11 MARINE ECOLOGY

Introduction

11.1 This section identifies and evaluates the nature and extent of potential impacts on marine ecological resources that may arise from the construction and operational phases of HATS Stage 2A. Baseline conditions, evaluation of potential impacts, and recommended mitigation measures, where necessary, are discussed.

11.2 The impacts arising from disinfection processes (E. coli levels, Dissolved oxygen depletion) and the potentially harmful products associated with this disinfection such as Total Residual Chlorine and Chlorination By-products are discussed in detail in the Agreement No. CE 7/2005 (EP) “Harbour Area Treatment Scheme Environmental Impact Assessment Study for the Provision of Disinfection Facilities at Stonecutters Island” (ADF EIA). For reference, a brief summary of the findings is presented below.

11.3 The ADF EIA concluded that no adverse ecological impacts associated with disinfection processes and subsequent discharge of disinfected effluent would be anticipated during operation of the Project because:

· Disinfection of sewage will improve the water quality in Western Buffer Water Control Zone and western Victoria Harbour Water Control Zone by reducing E. coli levels.

· The levels of total residual chlorine (TRC) and chlorination by-products (CBP) in the disinfected sewage effluent will only cause highly localised changes in water quality at the Stonecutters Island Sewage Treatment Works (SCISTW) outfall and thus there will be no unacceptable ecological risk on marine mammals and other marine life in relation to toxicity of TRC and CBP.

· As no adverse impacts on marine ecological resources are predicted, no mitigation measures are required.

11.4 This report focuses on the deterioration of water quality parameters and subsequent impacts arising from the construction and operation of HATS Stage 2A.

Environmental Legislation, Policies, Plans, Standards and Criteria

11.5 Evaluation of impacts on marine ecological communities resulting from the project is conducted according to criteria in the Technical Memorandum on Environmental Impact Assessment Process (EIAO TM). Annex 16 of the EIAO TM sets out the methodology for assessment of impacts and Annex 8 provides the criteria for the evaluation of ecological impacts.

11.6 Other legislative requirements and evaluation criteria relevant to the current study for the protection of species and habitats of marine ecological importance are summarised below.

l Wild Animals Protection Ordinance (Cap. 170), designated wild animals are protected from being hunted, whilst their nests and eggs are protected from injury, destruction and removal.  All marine cetaceans and sea turtles are protected under this Ordinance.

l The Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586) provides protection for certain plant and animal species through controlling or prohibiting trade in the species. Certain types of corals are listed in Schedule 1 of the Ordinance, including Blue coral (Heliopora coerulea), Organ pipe corals (family Tubiporidae), Black corals (order Antipatharia), Stony coral (order Scleractinia), Fire corals (family Milleporidae) and Lace corals (family Stylasteridae). Cetacea including whales, dolphins, porpoises, and rorquals are also listed under Schedules 1 & 2 of the Ordinance. The import, export and possession of scheduled corals, no matter dead or living, is restricted.

l The Marine Parks Ordinance (Cap. 476) and Subsidiary Legislation allows for designation, control and management of marine parks and marine reserves through regulation of activities therein to protect, conserve and enhance the marine environment for the purposes of nature conservation, education, scientific research and recreation.

l The amended Town Planning Ordinance (Cap. 131) provides for the designation of coastal protection areas, Sites of Special Scientific Interest (SSSIs), Conservation Area, Country Park, Green Belt or other specified uses that promote conservation or protection of the environment.

l EIAO Guidance Note No. 6/2002 clarifies the requirements of ecological assessments under the EIAO.

l EIAO Guidance Note No. 7/2002 provides general guidelines for conducting ecological baseline surveys in order to fulfil requirements stipulated in the EIAO TM.

11.7 Also relevant are the following national and international conventions and conservation treaties:

l International Union for Conservation of Nature and Natural Resources (IUCN) 2006 Red Data Books - provides taxonomic, conservation status and distribution information on threatened species that have been evaluated using the IUCN Red List Categories and Criteria. This system is designed to determine the relative risk of extinction, and the main purpose of the IUCN Red List is to catalogue and highlight those taxa that are facing a higher risk of global extinction.

l United Nations Convention on Biological Diversity of 1992.  The Convention requires signatories to make active efforts to protect and manage their biodiversity resources. The PRC is one of the contracting parties.

l The PRC National Protection Lists of Important Wild Animals and Plants - lists detail Category I and Category II key protected animal and plant species under Mainland Chinese Legislation.

Assessment Methodology

11.8 The marine ecological impact assessment was conducted in accordance with the EIAO TM Annex 8 and Annex 16. In accordance with the EIA Study Brief No. ESB-129/2005, the assessment area for the marine ecological impact assessment should be the same as the assessment area for water quality impact assessment.

11.9 For this EIA study, the ecological baseline conditions in the assessment area, comprising Water Control Zones (WCZs) of North Western, Western Buffer, Southern, Victoria Harbour, Eastern Buffer and Junk Bay, were elucidated via a desktop study of available current literature. A review of the ecological information available covering the assessment area, indicates that existing data is extensive. In the Agreement No. CE42/2001 Environmental and Engineering Feasibility Assessment Studies in Relation to the Way Forward of the Harbour Area Treatment Scheme (HATS EEFS) (CDM, 2004), a comprehensive literature review is presented as well as results of subtidal and intertidal surveys (to fill in data gaps). Other sources were also used to further supplement the information available in the HATS EEFS report.

Description of the Environment

11.10 The assessment area for the HATS 2A project includes the following water control zones as designated under the Water Pollution Control Ordinance (WPCO): Eastern Buffer, Southern, Victoria Harbour, Junk Bay, Western Buffer and North Western. This ecological baseline conditions in the assessment area are described below, comprising:

l Benthic communities

l Coral Communities

l Intertidal communities

l Marine mammals (Chinese White Dolphin, Finless Porpoise), Green Turtles, Horseshoe Crab

l Artificial Reefs (ARs) at Sha Chau and the International Airport

l Sha Chau and Lung Kwu Chau Marine Park, Cape D’ Aguilar Marine Reserve and SSSIs

11.11 Location maps of the ecological resources within the assessment area are shown in Figures 11.1a and 11.1b.

Benthic Communities

11.12 Recent detailed information on Hong Kong’s benthic community can be found from a study conducted for the Agriculture, Fisheries and Conservation Department (AFCD) in 2002, titled; Consultancy Study on Marine Benthic Communities in Hong Kong. This study was carried out by the City U Professional Service Limited. The study included 120 sampling stations (Figure 11.2) and was carried out during both the wet season (June-July, 2001) and dry season (November-December, 2001). AFCD reported that sediment in the assessment area, except the area near Sha Chau and Lung Kwu Chau Marine Park and areas near Soko Islands, is composed of very fine sand and silt or clay. The main species reported in this study are summarised below in Table 11.1. Species were only recorded as present if occurrence was ≥50% of 120 sampling stations. The location of the recorded species is organized to correspond to the current assessment area for HATS Stage 2A.

Table 11.1 Summary of Main Marine Benthic Species Recorded in Each WCZ During the AFCD (2002) Study

Species

NW

WB

VH

EB

JB

S

W

D

W

D

W

D

W

D

W

D

W

D

Polychaete

Mediomastus sp.

X

X

X

X

X

X

X

X

X

X

X

X

Sigambra hanaokai

X

X

X

X

X

X

X

X

X

X

X

X

Aglaphamus dibranchis

X

X

X

X

X

X

X

X

X

X

X

X

Sigambra sp.

X

X

X

X

X

X

Cossurella dimorpha

X

X

X

Ophiodromus angustifrons

X

X

X

X

X

X

X

X

X

X

Paraprionospio pinnata

X

X

X

X

X

X

X

X

X

X

Prionospio malmgreni

X

X

X

X

X

X

X

X

X

X

X

Prionospio ehlersi

X

X

X

X

X

Otopsis sp.

X

X

X

X

X

Crustacean

Callianassa japonica

X

X

X

X

X

Neoxenophthalmus obscurus

X

X

X

X

X

X

X

X

X

Echinoderm

Amphiodia obecta

X

X

X

X

X

X

X

X

Sipunculan

Apionsoma trichocephalus

X

X

X

X

X

X

X

X

Key: NW - North Western; WB - Western Buffer; VH - Victoria Harbour; EB - Eastern Buffer; JB - Junk Bay; S - Southern; X - Species present in WCZ; D - Recorded in dry season; W - Recorded in wet season. Species is only listed as present if occurrence was ≥50% of 120 sampling stations.

Source: Table is summarised from AFCD, 2002

11.13 The AFCD (2002) study reports that the species in Table 11.1 above were the most common and ubiquitous recorded and some of these species are also known to be well adapted to organic pollution. The most abundant species reported were, Polychaete annelids, Crustaceans and Bi-valves, comprising: 46.9%, 18.2% and 11.1% of the total species, respectively.

11.14 According to AFCD (2002), Species Richness (Margalef Index), Diversity (H’) and Evenness (J’) are reported in Table 11.2 for all sampling stations relevant to the HATS Stage 2A assessment area. Wade (1972) provided an evaluation of an exemplary highly diverse, minimally disturbed, soft bottom habitat using these same indicators. Wade reported high values in terms of species richness (d) >10, diversity (H’) >3 and eveness (J’) >0.8. This provides an evaluative framework to which the AFCD findings can be compared.

Table 11.2 Summary of Species Richness, Diversity and Eveness of Marine Benthic Communities in the WCZs Within Assessment Area

WCZ	Station	d		H’		J
		S	W	S	W	S	W
Northwestern Waters	9	3.45	1.90	0.94	1.43	0.31	0.80
	10	3.67	5.86	1.63	2.51	0.56	0.72
	11	5.18	8.03	1.30	1.94	0.37	0.48
	12	3.43	10.21	2.26	3.23	0.88	0.80
	13	5.89	3.52	2.56	2.30	0.80	0.87
	14	5.95	3.83	2.83	2.13	0.86	0.83
	15	6.51	5.91	3.12	3.01	0.93	0.93
	16	6.81	10.00	2.73	3.53	0.78	0.89
	17	6.63	6.08	2.25	2.40	0.62	0.67
	18	5.62	8.06	1.52	2.14	0.42	0.54
	19	6.92	9.13	2.64	2.94	0.71	0.74
	20	5.54	4.15	2.69	2.48	0.82	0.97
	21	6.80	7.20	2.66	2.98	0.73	0.83
Southern Waters	22	6.16	5.63	2.61	2.27	0.74	0.62
	23	11.33	10.79	3.15	3.52	0.74	0.86
	24	11.54	11.43	3.03	2.96	0.70	0.68
	25	10.36	10.36	3.13	3.09	0.79	0.76
	26	10.28	10.13	2.86	2.93	0.67	0.70
	27	9.21	10.70	3.29	3.22	0.84	0.79
	28	10.32	10.50	3.27	3.18	0.80	0.77
	29	9.86	10.63	3.10	3.20	0.76	0.76
	30	3.94	4.36	2.43	1.76	0.95	0.58
	31	5.91	7.74	2.85	2.83	0.89	0.77
	32	3.24	7.76	2.24	2.82	0.93	0.76
	33	8.57	11.00	2.74	2.77	0.71	0.66
	34	7.64	7.45	2.69	2.61	0.71	0.70
	35	6.46	7.78	2.92	3.00	0.83	0.82
	36	7.87	6.77	2.90	2.85	0.77	0.81
	37	8.03	8.05	3.20	3.01	0.86	0.81
	38	8.27	9.41	3.35	2.75	0.89	0.68
	39	7.67	7.74	3.02	3.27	0.83	0.93
	40	7.84	8.79	2.65	3.35	0.71	0.89
	41	6.02	4.83	2.78	2.56	0.80	0.85
	42	7.32	7.49	3.16	3.14	0.90	0.91
	44	4.80	4.55	2.68	1.93	0.95	0.64
	45	5.45	4.67	2.51	2.57	0.79	0.89
	47	2.91	4.35	1.83	2.59	0.80	0.96
	51	3.60	9.08	1.39	2.82	0.44	0.68
	55	6.59	6.16	2.62	2.79	0.73	0.84
	56	7.95	7.84	2.86	3.10	0.78	0.84
	57	9.11	6.57	3.31	2.94	0.88	0.87
	58	7.64	7.12	3.13	3.10	0.87	0.90
	59	7.23	6.65	2.89	2.84	0.81	0.83
	60	8.26	10.86	3.20	3.32	0.89	0.82
	61	9.40	8.20	3.43	3.25	0.91	0.88
	62	8.87	8.51	3.36	3.29	0.88	0.88
	63	6.57	4.44	2.96	2.55	0.88	0.88
	64	9.44	5.85	3.16	2.80	0.82	0.86
	65	5.14	4.79	2.24	2.57	0.70	0.83
	66	6.47	5.40	2.99	2.62	0.90	0.82
	70	8.32	7.68	1.63	1.53	0.42	0.38
Western Buffer	43	4.82	5.53	2.58	2.47	0.88	0.78
	46	5.21	6.65	2.65	3.14	0.85	0.97
	48	4.16	3.22	2.19	2.14	0.77	0.97
	49	5.16	6.42	2.66	2.92	0.85	0.88
	50	3.28	4.91	1.82	2.62	0.66	0.91
Eastern Buffer	75	13.17	11.98	3.50	2.96	0.81	0.68
	80	12.47	12.65	3.29	3.21	0.75	0.72
Junk Bay	85	5.44	5.04	2.73	2.43	0.87	0.77
Victoria Harbour	52	2.04	3.55	1.14	1.78	0.52	0.67
	53	6.46	5.84	2.35	2.36	0.60	0.63
	54	4.14	4.98	1.23	0.91	0.34	0.25

Key: The shaded values refer to values d>10, H>3 and J>0.8.

S – Recorded in summer, W – Recorded in winter.

Source: The above data is adapted from AFCD (2002)

11.15 As shown in Table 11.2, species richness, diversity and eveness in the assessment area are generally lower, than in Wade’s (1972) study, i.e. d = <10, H’ = <3 and J’ = <0.8. It is also apparent that there is lower species diversity and eveness in Victoria Harbour and Western Buffer WCZs compared to the Eastern and Southern waters. These indices thus reflect the response of benthic communities to local hydrographic, sediment type and water quality parameters. The lower diversity and eveness figures for most of Hong Kong waters, compared to Wade’s (1972) study, indicate a relatively high level of disturbance throughout the majority of the assessment area.

11.16 In Victoria Harbour WCZ, the benthic fauna is characterized by species that can adapt to eutrophic environments (AFCD, 2002). Based on Shin and Thompson (1982), the sea bed area in the North Point area is a muddy habitat made up of fine sands with high organic matter. The marine benthic community is dominated by the bivalve Tapes philippinarium and the polychaete Minuspio cirrifera. A more recent EIA report (Mouchel Asia Ltd., 2001) found that the benthic community in the middle of the harbour adjacent to Kai Tak Runway and Kung Tong Typhoon Shelter is dominated by the Amphipods; Cheiriphotis sp., and the Polychaetes; Elasmopus sp., Dorvillea sp., Lanice maera, Minuspio sp., Naineris sp., and Neanthes sp.. In the middle of the harbour, there are more species, higher total biomass and higher abundance of infaunal organisms than in the area near Kung Tong Typhoon Shelter. The lowest biomass and biodiversity were found near the Kai Tak runway.

11.17 A detailed description of the benthic marine species recorded in Sha Chau and Lung Kwu Chau (North Western WCZ) Marine Park was also provided in AFCD (2002). The Sha Chau and Lung Kwu Chau Marine Park had relatively low individuals and biomass compared with the entire assessment area. In summer, there were 13-33 species per 0.5 m², 66-220 individuals m^-2 and a biomass of 3.66-25.38 g m^-2. In winter, there were 52-57 species per 0.5 m², 328-484 individuals m^-2, and a biomass of 6.08– 9.88 g m^-2. The polychaete Mediomastus californiensis was dominant in both seasons. Other species common in summer were the polychaete Lumbrineris nagae, Mediomastus sp., Otopsis sp. and Aglaophamus dibranchis, and the bivalve Potamocorbula laevis. In the winter, other polychaetes were dominant, including Paraprionospio pinnata, Prionospio malmgreni, Prionospio pygmaea, Prionospio sp. and Sigambra sp.. No rare and protected benthic species were recorded.

11.18 The entire East Lamma Channel (Southern WCZ) has been surveyed for marine macrobenthic fauna by Binnie Consultants Ltd. (1994). It was found that the communities were dominated by invertebrates, with species richness (Margalef index) varying from 2.89 to 5.32 across all sampling stations. A total of 426 specimens were collected by grab sampling and these represented 63 taxa in eight phyla. The benthic epi- and in-fauna were characterised by 3 species of polychaetes in terms of abundance: Nephtys sp. (20.89%), Prionospio saccifera (17.14%) and Sternaspis scutata (12.68%).

11.19 A more targeted study on marine soft bottom benthic community was completed in 1999 for the Strategic Sewage Disposal Scheme Environmental impact Assessment Study (SSDS EIA) (Montgomery Watson et al., 1999). The major findings are summarised in Table 11.3.

Table 11.3 Benthic Characteristics in Areas Surrounding Lamma Island (Southern WCZ)

Community	Green Island	West Lamma	East Lamma	S. East Lamma
Characteristic Species	Glossobalanus sp. (90%) Aglaophamus lyrochatea Lumbrineris heteropoda Alpheus sp.	Aglaophamus lyrochatea Mabellarca consociate Glossobalanus sp. Typhlocarcinops transversa	Glossobalanus sp. Aglaophamus lyrochatea Mabellarca consociate Lumbrineris heteropoda	Aglaophamus lyrochatea Mabellarca consociate Alpheus sp. Scalopidia spinosipes
Common Species	Paraprionospio pinnata Heteromastus filiforms Mediomastus Californienis Typhlocarcinops transversa Sternaspis scutata Glycera chirori	Lumbrineris heteropoda Glycera chirori Cossurella dimorpha Eocylichna cylindrella Neoxenophthalmus Obscurus Scalopidia spinosipes	Heteromastus filiforms Paraprionospio pinnata Glycera chirori Sternaspis scutata Lumbrineris nagae Scalopidia spinosipes Alpheus sp. Amphioplus laevis	Glossobalanus sp. Cossurella Dimorpha Sternaspis scutata Ophelina Acuminate Eocylichna cylindrella Typhlocarcinops transversa Folfingia sp. Neoxenophthalmus obscurus
No. of Species	44	36	57	50
Density (ind./m2)	476	100	285	122
Biomass (g/m2)	47.93	40.74	30.78	57.18
H’	1.37	2.64	2.29	2.92
J’	0.41	0.84	0.66	0.84

H’ = Species Diversity, J’ = Eveness

11.20 These results indicated that ecological values of soft bottom communities in the area surrounding Lamma Island are relatively low. The communities are dominated by deposit feeding infaunal organisms such as Glossobalanus sp. As well as infaunal predatory species such as Glycera chirori.

11.21 Tathong Channel (Eastern Buffer WCZ) was reported to have the highest abundance and relatively high species richness. The cephalochordate, Branchiostoma belcheri (Amphioxidae), of conservation importance was recorded in the Tathong Channel and some other areas in eastern Hong Kong waters. Branchiostoma belcheri, is now designated as a second priority protection species in China.

11.22 Soko Islands in Southern WCZ has the second highest abundance, lower average biomass and the second highest taxonomic richness. Following this, Soko Islands and the Tathong Channel can be said to support high biodiversity (d>10, H’>3 and J’ >0.8).

11.23 An evaluation study (for Victoria Harbour WCZ) was carried out after the commissioning of the outfall of the Stonecutters Island Sewage Treatment Works (SCISTW) during SSDS Stage 1 and found that the benthic communities changed drastically right after the commission of the outfall, but recovered shortly after (Mouchel Asia Limited, 2001). There is therefore little evidence for the existence of an adverse impact on the benthic community in the Stonecutters Island area as a result of effluent discharge from SCISTW outfall.

11.24 At Sites of Special Scientific Interest (SSSI) Sham Wan (North Western WCZ) and Cape D’ Aguilar (Southern WCZ), the benthic community diversity is considered low because species richness (d) is less than 10.

11.25 The findings of the AFCD, 2002 study indicate that, apart from the record of Branchiostoma belcheri in the Tathong Channel, all species in the assessment area are common and widespread in Hong Kong.

11.26 For the HATS EEFS (CDM, 2004), further surveys were carried out covering more specific areas including, Stonecutters Island, East Lamma Channel, Sandy Bay, North Point, Junk Bay, Tathong Channel (see Figure 11.3 for sampling locations). These surveys are summarized below.

Stonecutters Island Area (Western Buffer/Victoria Harbour WCZ)

The infaunal benthic community at Stonecutters Island is characterized by low abundance, low biomass, and low biodiversity. The community is dominated by common small polychaetes and anthozoans in terms of the number, but over dominated by one anthozoan, Pteroeides sp., which is found in other soft benthic environments. The ecological value of marine benthos near SCISTW outfall is therefore very low.

East Lamma Channel (Western Buffer/Southern WCZ)

The infaunal benthic community is characterized by low abundance, very low biomass, and low biodiversity. The community is dominated by small polychaetes and molluscs. Most of these species are small individuals with very little conservation importance.

Sandy Bay (Western Buffer WCZ)

The infaunal benthic community in Sandy Bay is characterized by relatively high abundance, very high biomass, and high biodiversity. The infaunal community is equally represented by common polychaetes, crustaceans and echinoderms in terms of number, but over dominated by echinoderms in terms of biomass. Infaunal benthic species found here have very little conservation importance. Large variation in benthic community structure was detected among stations at this site.

North Point (Victoria Harbour WCZ)

The infaunal benthic community is characterized by the highest abundance, highest biomass and the highest biodiversity among the sites. The community is dominated by common polychaetes and molluscs. The most dominant species is the mollusc Ruditapes sp., which is a commercial species, although the conservation importance is not high. Although distribution of this mollusc is patchy in this area, in previous studies it is also reported as the dominant species. This indicates that the community structure in the North Point area has been relatively stable over time and thus is quite robust to environmental disturbance.

Junk Bay (Junk Bay WCZ)

The infaunal benthic community is characterized by very low abundance, low biomass and low biodiversity. The community is dominated by small opportunistic polychaetes and molluscs. All recorded infaunal species have very little conservation importance. The marine benthic environment is a relatively disturbed environment due to human activities.

Tathong Channel (Eastern Buffer WCZ)

The infaunal benthic community is characterized by relatively high abundance, low biomass and high biodiversity, a characteristic identified in most previous studies, indicating that the community structure is relatively stable. Despite a high biodiversity, the infaunal benthic community is dominated by small opportunistic species of polychaetes with very low conservation importance.

Summary of Baseline Benthic Conditions from Literature Review

Victoria Harbour and Western Buffer WCZs support the lowest species richness and evenness of benthic invertebrates and the value of marine benthos is therefore very low.

Northwestern, Junk Bay and a large proportion of Southern and Eastern Buffer WCZ do not support a high biodiversity of benthic communities.

The highest species diversity was recorded in Tathong Channel (Eastern Buffer WCZ), in the AFCD (2002) and HATS EEFS (CDM, 2004) surveys. The cephalochordate, B. belcheri (Amphioxidae), of conservation importance was recorded in the Tathong Channel and some other areas in eastern Hong Kong waters.

The dominant species in assessment area were generally polychaetes and mollusca in terms of abundance.

Coral Communities

11.27 In studies conducted for the Civil Engineering Department (Binnie Consultants Limited, 1995, 1997), the greatest diversity and abundance of hard corals were generally found in the north eastern waters of Hong Kong due to the optimal environmental conditions for settlement, growth and survival. Corals have also been recorded in the assessment area at; Lamma Island (Ngan Chau, Pak Kok, Luk Chau, Luk Chau Wan, Tung O Wan, Wong Chuk Kok, Sham Wan), Ap Lei Chau (Ap Lei Chau and Ap Lei Pei), near Sandy Bay (Telegraph Bay), near Junk Bay (Ching Chau and east of Tung Lung Chau) and at Kau Yi Chau. In particular, Kau Yi Chau, southern Lamma Island (Sham Wan, Tung O Wan and Wong Chuk Kok) and Tung Lung Chau were found to have good hard coral communities and high conservation importance.

11.28 More recently a survey conducted by ERM (1999) reported observation of significant hard and soft coral communities, with high ecological value, at the south western end of Lamma Island (Ha Mei Tsui south). In another survey, significant soft coral communities, with high ecological value, were observed at Green Island and Little Green Island (Babtie BMT Harris and Sutherland, 2000).

11.29 The Junk Bay area was surveyed in 2000 by M2 Environmental Ltd. A dive survey of hard shores found moderate hard coral abundance and diversity along the east coast of Tung Lung Chau just beyond Fat Tong Mun. The study reported good populations of gorgonians, soft corals and hard corals at relatively abundant levels in deep areas close to shore. The soft coral Dendroneptha sp. existed in low density and decreased in abundance with increasing depth. Distribution of gorgonians did not appear to be affected by depth. It is reported that that habitats and communities were healthy and that they appeared to be functioning well.

11.30 A coral survey conducted for AFCD (Oceanway, 2002), studied approximately 72km of sub-littoral benthic communities using three standardised ‘nested’ survey methods and the following was concluded:

l Hermatypic Corals are mainly distributed in the rocky sea area to the east of Hong Kong.

l Hong Kong waters do not support a major reef development. Incipient reefs were best developed in eastern and north eastern waters while south eastern and southern locations supported coral communities with less accretion and western waters had no accretion.

l The highest coral coverage was found in the northeastern and eastern waters (30-50% or even up to 75%), intermediate coverage in the south eastern and southern (10-30%) and the lowest in the western (<5% and usually <1%).

l 88 species in 30 genera of 12 families of the Scleractinia, were reported, which is much higher than in previous reports. The highest diversity occurred in eastern and north eastern waters (generally >20 species per site). Southern and south eastern waters supported about 20-30 species per site, whereas the western waters supported <20 species.

l Five major community types with strong geographic and environmental affinities and key indicator species were identified: Platygyra – Favia community in eastern and north eastern waters, Acropora solitaryensis – Montipora peltiformis community in eastern, south eastern and southern waters, Psammocora-Bryozoan community in western, southern and south eastern waters, Porites deformis – Cyphastrea community in north eastern and southern waters, and the soft coral-mollusc community in western and south eastern waters.

l At most sites, the corals were in good condition.

11.31 More up to date information available in the Field Guide to Hard Corals of Hong Kong (Chan et al., 2005) reports that there are currently 84 species of scleractinian corals from 28 genera of 12 families in Hong Kong waters.

11.32 Coral surveys (Figure 11.4) were also performed for the HATS EEFS (CDM, 2004) in the waters around Junk Bay, North Point, Stonecutters Island, Sandy Bay and the East Lamma Channel, as these areas had not previously been systematically studied. A summary of the findings is presented below:

Stonecutters Island (Western Buffer/Victoria Harbour WCZs)

The surrounding natural habitat of the SCISTW outfall had already been heavily disturbed with dense urban and industrial development along the extensively reclaimed coastline. No hard corals were found. A few soft corals were recorded along the southern shore of Tsing Yi, and the nearest significant soft and hard coral community was located near Kau Yi Chau and Green Island (approximately 4 km from SCISTW outfall). Green Island area did not support assemblages of hard corals but soft corals and gorgonians were abundant but of low diversity. Four species of soft coral and gorgonians including the Pink Soft Coral (Dendronephthya sp.), Orange Sea Fan (Echinogorgia complexa), White Sea Whip (Euplexaura curvata) and Purple Sea Whip (Ellisella gracilis) were recorded at Green Island and Little Green Island. The seabed was covered by thick mud with little hard substrate and the overall ecological value of the Stonecutters Island waters was considered low.

Ap Lei Chau (Western Buffer WCZ)

At Ap Lei Chau, the soft coral coverage is <5%, Echinomuricea sp., and Dendronephthya sp. were the two most common soft coral species. Fourteen species of hard corals were recorded with <5% coverage. Faviids were the most abundant taxon. The survey location at Ap Lei Chau had moderate to high hard coral diversity but coverage was low for both soft and hard corals. The distance between the SCISTW outfall location to the coral is approximately 9.1 km.

East Lamma Channel (Southern WCZ)

The northwestern water of Lamma Island had been modified considerably. South Lamma, however, remained relatively undisturbed except busy shipping lanes in the East Lamma Channel. The highest coral coverage was in Luk Chau Wan in comparison with other sites.

In Luk Chau Wan (approximately 9km away form the SCISTW outfall), there was very little soft coral (<5% cover) in deep transects and no hard corals recorded. However, the shallower transect recorded 23 species of hard corals with a percentage cover of 25-50%. Turbinaria peltata was the most abundant species and the Faviids were also well represented. In Sok Kwu Wan, <5% of soft coral cover and two genera were recorded in deep transect of which Echinomuricea was the most abundant. In the shallow transect hard and soft coral cover was <25%. Twenty-two hard coral species were recorded of which Platygyra acuta was the most abundant species with the Faviids generally well represented. The coverage and diversity of corals at Luk Chau Wan and Sok Kwu Wan were high.

In Luk Chau, along the deep transects, there was no hard coral and low numbers of soft coral. The middle zone again had no hard coral, soft coral community was dominated by Echinomuricea sp. with <25% percent cover. Hard and soft corals were recorded from the shallow transects with both having a percent cover of <5%. Dendronephthya sp. were the most abundant soft coral taxa and of the seven species of hard corals recorded, Plesiastrea vesipora was the most abundant.

Sandy Bay Area (Western Buffer WCZ)

The Sandy Bay area is a highly disturbed environment with re-created shoreline habitats. From spot-check dives to a maximum depth of 12m, both hard coral (14 taxa) and soft coral (5 taxa) were observed from surveys. The most ubiquitous taxa were the soft corals Echinomuricea sp. and the bryozoans Schizoporella errata.

In east Sandy Bay, there was little soft coral cover (<5%). Only small isolated Echinomuricea colonies were observed. Nine hard coral species were observed in the shallow transect with <5% cover. Psammocora superficialis and Porites lobata were the most abundant species and the Faviids were also well represented.

In west Sandy Bay, at both deep and middle transects, soft corals were present and had a percentage cover 10-50%. Seven genera were recorded with Echinomuricea sp. being dominant. In shallow water, soft corals were present with a percentage cover <10% with Echinomuricea sp. again being the most abundant taxa. 11 hard coral species with <5% cover were reported. Faviids were the most abundant hard corals.

The percentage cover of soft corals in east Sandy Bay was low. However at west Sandy Bay cover was medium. Percentage cover for hard corals in both east and west Sandy Bay was low. The species diversity was low compared with the adjacent East Lamma survey point. The distance between the SCISTW outfall location and the coral at Sandy Bay is approximately 5.8 km.

North Point (Victoria Harbour WCZ)

The coastline of North Point has been modified heavily due to extensive urban development. The water near North Point is a major navigation channel with high levels of disturbance from marine traffic. No hard and soft coral communities were reported in this study.

Junk Bay (Junk Bay WCZ)

Coral surveys covered east Joss House Bay, west Joss House Bay, east and west Junk Bay. From spot-check dives, 21 hard coral and 8 soft coral taxa were recorded. The most ubiquitous was the hard coral Cyphastrea sp. and the soft coral Echinomuricea sp.. Junk Bay has the most diverse soft coral communities while Joss House Bay and north-west Tung Lung Chau had reasonably diverse corals but a low cover of hard coral.

In east Joss House Bay, 23 species of hard corals were recorded with a percentage cover of 10-25% in the shallow transect. Of these hard corals, Platygyra acuta was the most abundant species. Faviids in general were well represented.

In west Joss House Bay, <5% coverage was reported for soft corals. Isolated Dendronephthya colonies were observed. On the shallow transect, 8 species of hard corals were recorded with a percentage cover <5%. Cyphastrea seralia was the most abundant species.

In east Junk Bay, <5% coverage soft corals were recorded on the deep transect. On the middle transect, soft corals coverage was 25-50% of which 6 genera were present with Echinomuricea sp. being dominant. On the shallow transect, soft corals were present with 10-25% cover with Echinomuricea sp. again being the most abundant. One colony of Acanthastrea echinata was also observed on the shallow transect.

In west Junk Bay, for the middle and deep transects, 25-50% coverage of soft corals was recorded. Seven species of soft corals were recorded with Echinomuricea sp. being dominant. At the shallow depth zone, soft corals were present with <10% coverage. Echinomuricea sp. again was the most abundant. Within the shallow area, 8 hard corals species were recorded with <5% coverage. Goniopora stuchburyi was the most abundant hard coral in this area. Junk Bay is approximately 13km from the SCISTW outfall.

East Hong Kong (near Cape Collinson – Eastern Buffer WCZ)

Near Cape Collinson, in the deep and middle depth transect, Echinomuricea sp. was dominant and the soft coral cover was between 10-50%. Within the shallow depth zone, the soft coral community was much more developed and diverse and the colonies were larger than those in deeper water. Seafans, gorgonians and other soft corals were recorded with a percentage cover of 25-50%. Seven species of hard coral were recorded in shallow transects with Goniopora stuchburyi being abundant, however, hard coral colonies were scattered with low percentage cover (<5%). The Cape Collinson area is over 18km from the SCISTW outfall.

South Tung Lung Chau (Eastern Buffer WCZ)

In south Tung Lung Chau, both deep and middle transects revealed that soft coral coverage was low (<5%) with only 4 genera present. Echinomuricea sp. was abundant. At shallow depth, soft corals were present but in very low numbers; 4 species of hard corals were recorded, but the colonies were scattered and percentage cover was low (<5%). South Tung Lung Chau is approximately 18km from the SCISTW outfall.

North Tung Lung Chau (Eastern Buffer WCZ)

In north Tung Lung Chau, <5% soft coral cover was recorded in both middle and shallow depth transects. Echinomuricea sp. was only present in very low numbers. Seven hard coral species were recorded in the shallow transect with 10-25% cover. Favites were dominant. North Tung Lung Chau is approximately 17km from the SCISTW outfall.

11.33 The “Further Development of Tseung Kwan O Feasibility Study, Environmental Impact Assessment (CEDD, 2005)” provided more information for the Junk Bay WCZ in Chiu Keng Wan. The findings are summarized below:

l The survey method employ the Rapid Ecological Assessment (REA) techniques with a total 200m² of belt transect at three different water depths (shallow, middle and deep) in September 2004.

l The survey results show that hard coral was sparse along the entire Chiu Keng Wan coast at all depth zones. Hard coral cover did not reach higher than 1% cover in any of the transects. Hard corals were typically small, of encrusting growth and attached to bedrock. In all, the surveys identified 8 species of hard coral from the Chiu Keng Wan coast namely Goniopora strtchburyi, Plestiastrea versipora, Psammocora superficialis, Oulastrea crispata, Favites pentagona, Favia cf. favus, Turbinaria peltata and the ahermatypic Tubastrea sp..

l The cover of soft coral was also generally low, ranging from 0-15%. The highest soft coral cover of 10-15% was found at South Chiu Keng Wan coast. 2 soft corals and 4 gorgonian seawhip / seafan corals were reported. Soft corals were Dendronephthya sp. and Cladiella sp.. The gorgonians were Echiomuricea sp., Menella sp. and Eulexaura sp.. No black corals were found during the surveys.

Coral Survey for HATS Stage 2A at Aberdeen Preliminary Treatment Works (PTW)

11.34 The only marine works to be carried out during the HATS Stage 2A project, involves the demolition and reconstruction of a small area of seawall at the Aberdeen PTW. To update the current knowledge on baseline conditions of corals at this site, spot check and REA surveys were carried out in February 2007 by Eco-Enviro Consultants Company. The survey report is given in Appendix 11.1. The results are summarised below.

l Spot check dives were carried out at 8 sites (Figure 11.5) along the shore of the Aberdeen PTW. The surveyed sites included the existing seawall, rocky/boulders and mud sediment. Species found included sea urchins, sponges, tubeworms and byrozoans. They were sparsely distributed species, found commonly in Hong Kong Waters.

l During the spot check survey, only coral species Oulastrea crispata was recorded at site 4.

l During the REA survey (100m transect, laid parallel to the shore) 8 Oulastrea crispata colonies were identified (Appendix 11.1a). All colonies found were small (approx. 3-5cm) and cover was low. Only three of these colonies were located in the proposed works area (Figure 11.13). It was also noted that all colonies were located on small boulders < 50cm in diameter so translocation would be possible.

l Oulastrea crispata is a common species found throughout Hong Kong waters including the more turbid and harsh western waters (Chan, et al. 2005). Oulastrea crispata has a wide range of adaptations to different environmental conditions (including those unfavourable to corals) as well as geographic locations, which is a result of its stress-tolerant ability (Chen, et al. 2003). With an opportunistic life history trait, a wide range of reproductive strategies and surface-orientation independent growth, Oulastrea crispata is able to colonise a variety of substrata and to flourish as a pioneer coloniser of newly immersed structures (Lam, 2000a & 2000b).

l Owing to the sparse cover, small size, low species richness and commonness of the coral found, the marine habitat of the survey site is considered as having low ecological value. No other rare or species of conservation importance were recorded during the surveys.

11.35 No further field survey on coral communities is deemed necessary as all gaps in the data were addressed.

11.36 A summary of the above literature review on coral community baseline conditions within the HATS Stage 2A assessment area is presented below.

· In the Victoria Harbour WCZ, the Green Island area did not support assemblages of hard corals but soft corals and gorgonians were abundant and of low diversity (CED, 1998). In areas within Victoria Harbour WCZ other than Green Island, no corals were recorded, and thus the ecological value for coral community in this habitat is low.

· In the Western Buffer WCZ, a few soft coral species were found at Tsing Yi waters nearest to the SCISTW outfall. Further to the south, at Ap Lei Chau and West Lamma (within Sandy Bay Area), low to moderate diversity of hard coral species were recorded (14 taxa) but the percentage cover was low (<5%). The highest percentage of soft coral cover was recorded from West Lamma (10-50%). No rare species were recorded. In terms of species richness and biodiversity, the ecological value for the coral community in this WCZ is considered as low to moderate.

· In the Northwestern WCZ, both soft and hard corals were recorded. Corals were recorded in Sha Chau and Lung Kwu Chau Marine Park, Sham Tseng and Tsing Lung Tau. Soft corals are dominant in this WCZ, with occasionally one colony of hard coral, or less than 1% coverage in this WCZ. All the species recorded were common and widespread in Hong Kong. The ecological value for corals community for this WCZ is considered as low.

· In the Southern WCZ, there were many areas with corals cover. Stretching from Soko Island in south Lantau to Beaufort Island, the coral species richness and diversity and varied from place to place. Sham Wan were identified as a coral richness hotspot with a rare species Stylocoeniella sp.. Cape D’ Aguilar was designated as Marine Reserve, for its geological and geomorphological interest (AFCD 2004) as well as high biodiversity of coral species. Sung Kong and Waglan Island supports (10-30%) hard coral covers. Sok Kwu Wan (25-50%) and Luk Chau Wan (<25%) also support moderate-high coral coverage and more than 20 hard coral species recorded. In terms of species richness, biodiversity, coral communities in Sung Kong, Waglan, Sok Kwu Wan, Luk Chau Wan, Sham Wan, Tai Tam and Cape D’ Aguilar are considered as high ecological value. Other coral communities with low species richness and supporting low coral covers (1-5%) are considered as low ecological value: in Southern WCZ, Chung Hum Kok, Po Toi, Peng Chau, Hei Ling Chau, Cheung Chau and Cheung Sha Wan in South Lantau. Po Toi, East Beaufort Island, Hei Ling Chau, Cheung Chau, Cheung Sha Wan in South Lantau, Siu A Chau (Soko Island) and Peng Chau, Tai Lei mainly supports soft coral.

· In the Junk Bay WCZ, Chiu Keng Wan support soft corals from 0-10 % and the hard corals coverage were <1%, with low species diversity. Species recorded were identified as common and widespread species in Hong Kong. While from the HATS EEFS, a maximum of 23 hard coral species were recorded in East Joss House Bay with 10-25% cover; at other locations like West Joss House Bay and East and West Junk Bay, the percentage cover of hard coral was <5% with < 8 hard coral species recorded. The ecological value for corals community in this WCZ in terms of species abundance, rarity, diversity was considered as low-moderate.

· In the Eastern Buffer WCZ, surveys were made in areas near Cape Collinson and Tung Lung Chau. The coral coverage in Cape collinson for soft coral and hard coral were 10-50% and <5% respectively. Both soft coral and hard coral recorded were common and of low biodiversity. Due to the moderate high soft coral coverage, the ecological value for the coral community recorded was considered as low-moderate. For Tung Lung Chua, south of Tung Lung Chau supported low percentage cover (<5%) for both soft and hard coral, while for north of Tung Lung Chau, the hard coral coverage ranged from 10-25%, still with low soft coral cover (<5%). The survey results indicated that Cape Collinson supported moderate soft coral coverage, while north Tung Lung Chau supported moderate hard coral coverage. However, no protected or rare species were recorded.

Intertidal Communities

11.37 Intertidal communities in the assessment area comprised of rocky shores, artificial seawalls, sandy shores and mudflat.

11.38 Intertidal surveys for the HATS EEFS (CDM, 2004) were conducted at Fat Tong Chau, Junk Bay, Tung Lung Chau, Lamma Island and Sandy Bay in September 2002. The study area for HATS EEFS covered the assessment area of this EIA Study including Western Buffer (Sandy Bay and Lamma Island), Junk Bay (Junk Bay and Fat Tong Chau) and Eastern Buffer (Tung Lung Chau). The survey areas are presented in Figure 11.3 and representative photos of different intertidal communities in Appendix 11.2 of this EIA. A summary of the findings are presented below:

Lamma Island (Southern WCZ)

· In total, 13 species of invertebrates were found in the intertidal rocky zone; with 3 species in the high intertidal zone, 11 species in the mid intertidal zone and 12 species in the low intertidal zone. Among all invertebrates identified, grazing snail Nodilittorina trochoides and N. vidua were dominant and made up of 28.8% and 39.7%, respectively, of total individuals found in the intertidal zones. Other abundant invertebrates included the grazing snail Monodonta labio and limpet Siphonaria siria. A summary of the abundant invertebrates recorded across the vertical zonation of the intertidal rocky shore is presented in Table 11.4.

Table 11.4 Vertical Zonation of Abundant Invertebrates Recorded on Lamma Island Intertidal Rocky Shore

Vertical Zonation	Dominant Species in terms of abundance
High Intertidal Zone	N. trochoides N. vidua
Mid Intertidal Zone	Monodonta labio Siphonaria siria
Low Intertidal Zone	M. labio S. siria Acanthopleura japonica Thais clavigera

Sandy Bay (Western Buffer WCZ)

· In total, 15 species of invertebrates were found in the intertidal rocky zone; with 2 species in high intertidal zone, 9 species in mid intertidal zone and 13 species in low intertidal zone. Among all invertebrates identified, grazing snail N. vidua was the most dominant and represented 22.2% of total individuals found in the intertidal zones. Other abundant invertebrates included grazing snail N. trochoides (15%), M. labio (10.85%) limpet S. siria (11.7%) chiton A. japonica (12.4%). A summary of the abundant invertebrates recorded across the vertical zonation of the intertidal rocky shore is presented in Table 11.5.

Table 11.5 Vertical Zonation of Abundant Invertebrates Recorded in Sandy Bay Intertidal Rocky Shore

Vertical Zonation	Dominant Species in terms of abundance
High Intertidal Zone	N. trochoides N. vidua
Mid Intertidal Zone	M. labio S. siria N. vidua
Low Intertidal Zone	Cellana grata S. siria A. japonica Patelloida pygmaea

Junk Bay (in Junk Bay WCZ)

· In total, 17 species of invertebrates were found in the intertidal rocky zone; with 5 species in high intertidal zone, 16 species in mid intertidal zone and 13 species in low intertidal zone. Among all invertebrates identified, grazing snail N. trochoides and N. vidua were dominant and made up 34.7% and 26.1%, respectively, of total individuals found in the intertidal zones. Other abundant invertebrates included grazing limpet S. siria (18.2%) and Cellana toreuma (11.2%). A summary of the abundant invertebrates recorded across the vertical zonation of the intertidal rocky shore is presented in Table 11.6.

Table 11.6 Vertical Zonation of Abundant Invertebrates Recorded in Junk Bay Intertidal Rocky Shore

Vertical Zonation	Dominant Species in terms of abundance
High Intertidal Zone	N. trochoides N. vidua
Mid Intertidal Zone	N. trochoides N. vidua C. toreuma
Low Intertidal Zone	C. toreuma S. siria P. pygmaea A. japonica Acorn barnacle, Tetraclita squamosa Bivalve, Septifer virgatus Thais clavigera

Fat Tong Chau (in Junk Bay WCZ)

· In total, 15 species of invertebrates were found in the intertidal rocky zone; with 5 species in high intertidal zone, 9 species in mid intertidal zone and 15 species in low intertidal zone. Among all invertebrates identified, grazing snail N. trochoides and N. vidua was the most dominant and made up of 39.3% and 41.6.1%, respectively, of total individuals found in the intertidal zones. A summary of the abundant invertebrates recorded across the vertical zonation of the intertidal rocky shore is presented in Table 11.7.

Table 11.7 Vertical Zonation of Abundant Invertebrates Recorded in Fat Tong Chau Intertidal Rocky Shore

Vertical Zonation	Dominant Species in terms of abundance
High Intertidal Zone	N. trochoides N. vidua
Mid Intertidal Zone	N. trochoides N. vidua M. labio
Low Intertidal Zone	M. labio S. siria P. pygmaea T. clavigera

Tung Lung Chau (in Eastern Buffer)

· In total, 15 species of invertebrates were found in the intertidal rocky zone; with 4 species in high intertidal zone, 14 species in mid intertidal zone and 12 species in low intertidal zone. Among all invertebrates identified, grazing snail N. trochoides and N. vidua was the most dominant and made up of 33.9% and 20.2%, respectively, of total individuals found in the intertidal zones. Other abundant invertebrates included the grazing limpet C. grata (13.4%) and C. toreuma (7.5%). A summary of the abundant invertebrates recorded across the vertical zonation of the intertidal rocky shore is presented in Table 11.8.

Table 11.8 Vertical Zonation of Abundant Invertebrates Recorded in Junk Bay Intertidal Rocky Shore

Vertical Zonation	Dominant Species in terms of abundance
High Intertidal Zone	N. trochoides N. vidua
Mid Intertidal Zone	C. grata C. toreuma
Low Intertidal Zone	C. grata S. siria P. pygmaea T. squamosa S. virgatus T. clavigera

Artificial Seawall (Victoria Harbour WCZ)

· Recent results presented in the HATS Dive Survey Report for spot dives conducted close to seawalls inside Victoria Harbour (e.g. off Kai Tak, Hung Hom and North Point) in January 2003 recorded bryozoans (Schizoporella errata), barnacles, mussels (Perna viridis) and sponges. Morton and Morton (1983) suggested that common ‘biofouling’ organisms previously recorded on artificial seawalls and wharfs in Hong Kong include barnacles (Tetraclita squamosa, Capitelum mitella and Balanus amphitrite), polychaete tube-worms (Hydroides elegans, Spirobis foraminosus), mussels and oysters (Perna viridis, Septifer virgatus, Saccostrea cucullata), bryozoans (Bugula neritina), ascidians (Ascidia sydneiensis, Ciona intestinalis, Styela plicata) and various macro-algae (Ulva fasciata, Entromorpha prolifera, Codium cylindricum, Colpomenia sinuosa).

11.39 Almost all the recorded species in HATS EEFS (CDM, 2004) from intertidal rocky shore were herbivorous grazers and filter feeders. The artificial seawall supported bio-fouling species. Most of the species recorded in HATS EEFS were common and widespread in Hong Kong rocky shores and no rare species were recorded.

Junk Bay WCZ

11.40 Recent ecological surveys for the “Further Development of Tseung Kwan O Feasibility Study, Environmental Impact Assessment (CEDD, 2005)” conducted at Chiu Keng Wan provide information on intertidal community of Junk Bay WCZ. The habitats along Chiu Keng Wan comprise rocky shore (including rock pools), sandy shore and artificial seawall. The location of surveys is provided in Figure 11.6. The key findings are presented below:

Rocky Shore

· Ecological surveys were conducted twice at the rocky shore in Chiu Keng Wan in May and October 2004.

· Rocky shore fauna along the Chiu Keng Wan coast comprised species typical of other semi-exposed rocky shores of eastern Hong Kong waters and followed typical vertical zonation patterns mediated by tidal exposure. A summary of abundant invertebrates recorded in vertical zonation of intertidal rocky shore in the study period is presented in Table 11.9.

Table 11.9 The Vertical Zonation of Abundant Invertebrates Recorded in Junk Bay Intertidal Rocky Shore

Vertical Zonation	Dominant Species in terms of abundance
High Intertidal Zone	Nodolittorina spp. Ligia exotica
Mid Intertidal Zone	Tetraclita spp. M. labio C. toreuma
Low Intertidal Zone	Rock Oyster, Saccostrea cucullata Mussels, Sepifera virigatus Common Rock Crab, Grapsus albolineatus.

Rock Pools

· Along the Chiu Keng Wan coast, fish recorded in rock pools included the goby Bathygobius fusca and a single incidence of a stranded Doublebar cardinalfish (Apogon pseudotaeniatus). During the survey in May, it was also noted that small open tidal gullies along the low rocky shore provided shelter for dense schools of unidentified fish fry. Small schools of fish fry as well as juvenile Grey Mullet Mugil cephalus were also occasionally observed passing along the waters edge, whilst angler’s catches were noted to include Rockfish, Sebasticus marmoratus, Russell’s Snapper Lutjanus russellii, White-spotted Rabbit Fish Siganus canaliculatus, Chinese Damselfish Neopomacentrus bankieri, Japanese Seaperch Lateolabrix japonicus and Red Drum Sciaenops ocellatus.

· One marine species of potential conservation importance was discovered at the rocky shore habitat at Chiu Keng Wan. In May 2004, a large rock pool up to 70cm deep located on the high shore. The rock pool had a dense growth of Enteromorpha seaweed, sand/rubble/small boulder bottom substrata and contained 5 individuals of the Grassy Puffer fish (also known as the Starry or Snowy Puffer), Takifugu niphobles. Several other dead individuals were found stranded on the high shore nearby. Ad hoc surveys conducted in October 2004 focusing on this species found two individuals, T. niphobles in a large rock pool in Chiu Keng Wan.

· T. niphobles is listed as ‘data deficient’ in The IUCN Red List of Threatened Species (Roberts 1996, UNEP/GEF 2003). Listing of taxa in this category indicates that more information is required and acknowledges the possibility that future research will show that threatened classification is appropriate. As an intertidal spawner, T. niphobles gathers at the waters edge at dusk at the full or new moon when tidal heights are at their highest and strands in rock pools to spawn. Spawning is stimulated by groups of 2-4 males that bite and hang on the side of single females as they deposit eggs in sand and rubble at high tide. Individuals may remain stranded in rock pools on the high shore, until they are freed by the next high tide (Yamahira 1997a,b). The fish species T. niphobles, of conservation importance was recorded in rock pool in Chiu Keng Wan. It is listed in IUCN Red List of Threaten Species. Despite its IUCN listing, T.niphobles has a widespread regional distribution, with records from throughout the Pacific North-west region (including Japan, Korea, Taiwan, China, Hong Kong and Vietnam, Roberts, 1996). According to Sadovy & Cornish (2000), T. niphobles “is moderately abundant in Hong Kong and is known recently from several individuals along shallow boulder shores, such as within the Cape D’ Aguilar Marine Reserve”. Although it appears not to be among species recorded during monitoring of artificial reefs (Wilson 2003), this may be because it generally occupies waters that are shallower than the depths at which artificial reefs are deployed. Other researchers (e.g. Yu & Yu 2002) have also reported this species to be common in Hong Kong coastal waters.

Sandy Shore

· Sandy shore surveys were conducted at low tide in May 2004 and October 2004 along Chiu Keng Wan.

· At Chiu Keng Wan, the factors contributing to the apparent presence of very few burrowing macrofauna are likely to include water pollution and the coarse grain size of sand on the beaches. Only Large Ghost Crab (Ocypode ceratophthalma) were recorded from burrows on this sandy shore. Pollution caused by anthropogenic activities is a possible source of low species diversity on soft shore habitats. Eutrophication of sandy shore habitats at Chiu Keng Wan was suggested by the presence of large numbers of pollution tolerant polychaete tube-worms (Hydroides elegans) on the underside of boulders found along the shores. Sandy shores with coarse grain size are well-draining, which limits interstitial water retention leading to rapid desiccation of the shore and hence intolerable conditions for sandy shore infauna at the intertidal zone.

Artificial Seawall

· A study recorded in Morton and Morton (1983) on re-establishment of intertidal communities on the fringes of reclaimed land in Hong Kong indicated that it might take some eight to ten years for assemblages of colonising intertidal organisms to reach peak complexity (i.e. a ‘climax’ community state). Given that seawalls in Junk Bay are relatively new, it can be inferred that these seawalls support limited intertidal biota and are of low ecological value.

· Morton and Morton (1983) reported that only common biofouling species would be found from artificial seawalls.

Western Buffer WCZ

11.41 Information on intertidal shores in the Western Buffer WCZ is available from the “Improvement to Castle Peak Road between Ka Loon Tsuen and Siu Lam, Environmental Impact Assessment Study (Highways Department (HyD), 2001)”, is summarised below:

· The coastal waters near Tai Lam Chung are low in salinity with moderate wave exposure (Morton and Morton, 1983). The marine ecological habitats in the study area are categorized into natural boulder coast, artificial seawall and beach.  The artificial seawall is located between Siu Lam and the area near Ka Loon Tsuen, while the natural boulder coastline and sandy beach is located in Ka Loon Tsuen. Field surveys were conducted on the natural boulder coastline and the artificial seawall at Ka Loon Tsuen in May 2000.

Natural Boulder Coastline

· The natural boulder coastline is a typical sheltered rocky shore with little exposure to strong-waves.  The field survey indicated that the assemblages were typical of sheltered shore communities with high quantities of winkles, Nodilittorina radiata, dominating the lower shore.  Other intertidal species including common whelk, Thais sp., limpet, Cellana toreuma, smooth limpet, Notoacmoae sp., false limpet, Siphonaria spp. and barnacles Tetraclita japonica were recorded.  No rare species was recorded in the surveys.

Artificial Seawall

· The artificial seawall had been in place for over 20 years and small marine organisms had colonized along this old reclaimed sea-edge (HyD, 1996). Species composition was identified at the artificial seawall in Ka Loon Tsuen. The field survey indicated that the assemblages were typical of moderately exposed rocky shore communities with high quantities of Littoriaria articulata dominating the higher shore and Monodonta sp. dominating the lower shore.  Other intertidal species included Nodilittorina radiata, Cellana toreuma, Notoacmaea sp., Nerita albicilla and Thais sp..

11.42 At Aberdeen PTW a small area of seawall will be demolished and reconstructed and therefore intertidal surveys to strengthen knowledge on the baseline conditions were considered necessary. Intertidal surveys were conducted on January 26^th and November 6^th 2007 and March 6^th 2008. The results are summarised below.

· The whole coastline in the area was homologous artificial vertical seawall. No natural coastline was identified in the area. The vertical seawall is about 8m high and half of it is submerged in the water. The low tide mark is approximately 4m above the sea bottom.

· Transects were laid from the top of the seawall at Aberdeen PTW to the low tide mark. Transects were approx. 4m long. Quadrat samples with a sampling dimension 0.5 m x 0.5 m were taken at 1m intervals along the transects. Sessile epifauna within the quadrats were identified, counted and recorded. See Figure 11.7 for location of transects at Aberdeen PTW..

Table 11.10 Intertidal Survey Results from Aberdeen PTW

· A total of 8 species were recorded during the surveys. These were Cellana grata (Limpet), Monodonta labio (Topshell), Tetraclita squamosa (Acorn Barnacle), Acanthoplerua japonica (Chiton), Capitulum mitella (Stalked Barnacle), Siphonaria laciniosa (False Limpet), Thais clavigera (Dog Whelk) and Ligia exotica (Sea Slater). The dominant species on all transects were Capitulum mitella and Tetraclita squamosa. The distribution pattern of organisms was found to be quite similar at all transects, however the number or individuals was much higher at transect B when compared to the other transects. All species recorded are common and widespread in Hong Kong.

· No species of conservation importance or nursery/breeding activities was observed or recorded on the site. Because of the low diversity, species richness and the commonness of the species observed, ecological value of the site was considered low.

11.43 No further field survey on intertidal communities is deemed necessary as all gaps in the data were addressed.

Beach

· Species composition was identified at the beach in Ka Loon Tsuen.  Five cores (diameter 10cm, length 40cm) were sampled at high and low shores. The samples were sieved and stained with rose bengal.  No macro-invertebrate was recorded in this field survey.

Southern WCZ

11.44 Intertidal habitats in Southern WCZ are comprised of Artificial Seawall and Rocky Shores.

11.45 Information on artificial seawall in Southern WCZ is available from the “Helipad at Yung Shue Wan, Lamma Island, Environmental Impact Assessment (CEDD, 2006)” and is summarised below:

Artificial Seawall

· The ecological survey was conducted in March 2003. The sloping seawall was approximately 200m long and an epifauna community was present only at the lower part, within the tidal range. The limpet Cellana toreuma and the top shell Monodonta australis dominated the community. Other species, widespread on the lower wall, but less abundant, were the amphipod Ligia exotica and the acorn barnacle Teraclita squamosa. The pockets between the boulders of the sloping seawall were barren and no vegetation had become established. The limpets C. toreuma and M. labio dominated the artificial seawall and are common and widespread intertidal species found in Hong Kong. No rare and protected species were recorded from this study.

11.46 Information on intertidal community Rocky Shore diversity is available from the “Peng Chau Sewage Treatment Works Upgrade, Environmental Impact Assessment (DSD, 2004)”. The findings are summarised below.

Rocky shores

· The ecological surveys were conducted near Tai Lei Island in June 2003 and February 2003. In total, 13 and 15 infaunal species were recorded along Tai Lei Island in the dry and wet season respectively. The dominant species recorded in both dry and wet seasons were N. vidua, Patelloida saccharina and C. toreuma. One study site was an artificial seawall, and M. labio, C. toreuma, N. trochoides and N. radiate were found in this study. Table 11.11 summarizes the dominant species (>30% of total infaunal abundance) recorded in the vertical zonation along rocky shores in Tai Lei Island. The limpets N. vidua, Patelloida saccharina and C. toreuma which dominated the intertidal rocky shore were common and widespread intertidal species found in Hong Kong. No rare and protected species were recorded from this study.

Table 11.11 Vertical Distribution of Dominant Species in Intertidal Rocky Shore

Vertical Zonation	Tai Lei Island (Dominant Species)
	Dry Season	Wet Season
High Intertidal Zone	N. vidua N. radiate	N. vidua N. radiate
Mid Intertidal Zone	C. toreuma P. saccharina	P. saccharina P. pigmata
Low Intertidal Zone	P. saccharina Siphonaria atra C. toreuma	C. toreuma

11.47 For the “Outlying Islands Sewage Stage 1, Phase II and Package J – Sok Kwu Wan Sewage Collection, Treatment and Disposal Facilities, Environmental Impact Assessment (DSD, 2003)” a verification survey for intertidal habitats was performed in April 2002 to verify the 1999 data on Sok Kwu Wan (in Southern WCZ) semi-exposed rocky shores. A summary of findings is presented below.

· In total, 10 taxa and 385 species were recorded from the verification survey. The top three dominant species in terms of abundance were N. pyramidalis, Tetraclita sp. and Saccostrea cucullata. These species are common and widespread in Hong Kong. No rare and protected species were recorded from this study. The survey findings were consistent with that of the previous survey in 1999.

11.48 Ecological surveys were carried out on monthly basis on springs low tides between November 1996 and October 1998 at Cape D’ Aguilar Marine Reserve semi-exposed rocky shore (Hutchinson, 1999). The shore consisted of even sloping rock surfaces, sparsely covered with sessile invertebrates. Public access was limited and collection of organisms was prohibited, so there was limited anthropogenic disturbance. In summer, the rocky shore was dominated by algae Ralfsia expansa, Hapalospongidion gelatinosum, Hilderbrandia rubra. In winter, it was dominated by mollusca grazers; Acanthopleura japonica, Cellana toreuma, Patelloida saccharina, Monodonta labio and Nerita albicilla. The species recorded were typical of semi-exposed shores. No rare species were recorded. All species were common and widespread in Hong Kong.

Northwestern WCZ

11.49 Intertidal habitats in Northwestern WCZ are comprised of Rocky Shores, Sandy Shores and Mudflat.

11.50 The “Siu Ho Wan Water Treatment Works Extension, Environmental Impact Assessment (DSD, 2004a)” provides recent information on intertidal community in the Northwestern WCZ. The data is summarised below:

· Ecological surveys covering the wet season were conducted from July 2003 to October 2003 in Pui O Bay. In addition, ad hoc observations of fauna were made during site visits conducted in the 2003/2004 dry season.

Rocky Shore

· Rocky shore habitat was identified in the southwest corner of the assessment area fringing Pui O Bay.  The rocky shore comprised moderate to large rocky boulders with medium wave exposure. Rocky shore habitat supported typical and widespread species of moderately exposed rocky comprising rock oysters (Saccostrea cullculata), barnacles (Tetraclita sp., Capitella mitella), sea slaters (Ligia exotica), small shore crabs (Hemigrapsus sanguineus), limpets (Notoacmaema schrenkii) and snails (Monodonta labio, Nerita albicilla and Morula musiva).

Sandy Shore

· Sandy shore habitat supported ghost crabs (Ocypodes ceratophthalmus, Ocypodes gaimardi) with frequent burrows at the high shore.  Sand-bubbler crabs (Scopimera globosa) were also occasionally recorded. Hermit crabs (Clibanarium sp.) were infrequently recorded usually inhabiting Turitella shells. Surf clams (Donax sp.) were occasionally recorded on the low shore. At the backshore, the common sesarmine crab Perisesarma bidens was commonly recorded particularly in a small pool area behind the western end of Pui O beach.

11.51 The sandy shore in Pui O Wan is a gazetted beach and supported mostly the common crab species, while the semi-exposed rocky shore supported common and wide spread species in Hong Kong. No rare species were recorded.

11.52 The intertidal survey for the “Tung Chung – Ngong Ping Cable Car Project, Environmental Impact Assessment (MTRC, 2003)”, included sandy beaches (with small boulders) in Tung Chung Bay and Mudflat communities at San Tau. It was conducted in June and July 2002. This study is summarised below.

San Tau Mudflat

· On the mudflats beside San Tau colonies of the seagrass Halophila ovalis and Zostera japonica were recorded. The seaweeds Enteromorpha sp. and Colpomenia sinuosa were also seasonally abundant on the mudflat near the seagrass beds. The epifauna and infauna communities were dominated by gastropods. The mudflat was also an important habitat for the horseshoe crabs Tachypleus tridentatus and Carcinoscorpius rotundicauda. The mudskipper Periophthalmus cantonensis is widespread. The gastropod species dominating the mudflat included Cerithidea djadjariensis, Batillaria multiformis, Batillaria zonalis, Nerita striata and Clithon oualaniensis. These species entirely covered the mudflat in some areas. Other occasional epifauna species were the mudskipper Periophthalmus cantonensis that was present wherever there were tidal pools and the crab Uca chlorothalamus. The crab Uca lactea was locally dominant at open and elevated (well drained) areas of mudflat near the backshore.

Tung Chung Bay

· The Bay’s estuarine waters linked the coastal marine environment and the freshwater habitats of San Tau Stream and Tung Chung Stream. Due to the variable physio-chemical environment brought about by changing salinity in the Bay, the coastal waters supported a diversity of fish species. The most abundant species included the Flathead Mullet (Mugil cephalus) and Tiger Fish (Therapon jaruba).

11.53 Intertidal survey’s were carried out in Sha Chau Island and Lung Kwu Chau Island rocky shores between October 2003 and November 2004 as recorded in the “Biological Monitoring in Sha Chau and Lung Kwu Chau Marine Park, Final Report submitted to the Agriculture, Fisheries and Conservation Department, HKSAR (Put O Ang, Jr. et al, 2005)”. The dominant species included Littoraria articulate, Saccostrea cucullata, Balanus Amphitrite, Tetraclita squamosa, Nodilitorina trochoides, Septifer virgatus and juvenile snail (<1mm). In upper shore, it was dominated Littoraria articulate, Tetraclita squamosa, Nodilitorina trochoides, Septifer virgatus and juvenile snail (<1mm). In upper shore, it was dominated Littoraria articulate, Tetraclita squamosa, Nodilitorina trochoides, and juvenile snail. In middle shore, it was dominated by Littoraria articulate, Saccostrea cucullata, Balanus Amphitrite and Tetraclita squamosa. In lower shore, it was dominated by Littoraria articulate, Saccostrea cucullata, Balanus Amphitrite, Tetraclita squamosa and Septifer virgatus. In general, the middle supported highest species diversity. The species recorded were typical semi-exposed shore species. No rare species were recorded. All were common and widespread in Hong Kong.

11.54 A summary of intertidal community baseline conditions in the HATS Stage 2A assessment area is presented below.

· The coastline in the assessment area comprises habitat types including sandy shore, rocky shore, boulder shore, mudflat, and artificial seawall and boulder shore.

· Most of intertidal habitats in the assessment area support low biodiversity and are dominated by common and widespread infauna of Hong Kong. Sea grasses, Halophila ovalis and Zostera japonica were recorded at San Tau mudflat. Seagrass, Halophila beccarii, was recorded in Tai Ho Wan in (The University of Hong Kong 1999). Juvenile Horseshoe crabs were recorded from the San Tau Mudflat. Takifugu niphobles was recorded from a large rock pool in Chiu Keng Wan. This species is listed IUCN Red List of Threatened Species. However, Takifugu niphobles is moderately abundant in Hong Kong and is known recently from several individuals along shallow boulder shores, such as within the Cape D’ Aguilar Marine Reserve. Although it appears not to be among species recorded during monitoring of artificial reefs (Wilson 2003), this may be because it generally occupies waters that are shallower than the depths at which artificial reefs are deployed. Other researchers (e.g. Yu & Yu 2002) have also reported this species to be common in Hong Kong coastal waters.

· Sandy shores are dominated by species such as the large ghost crab, while rocky shores, are usually dominated by grazing snails N. trochoides and N. vidua and grazing limpets C. toreuma. Artificial seawalls, were dominated by common widespread species, with low ecological value. Infaunal composition most likely to be biofouling species (Morton and Morton, 1983).

Marine Mammals, Green Turtles and Horseshoe Crabs

11.55 Some of the assessment area is frequented or traversed by cetaceans, sea turtles and horseshoe crabs, which are all species of conservation importance.

Marine Mammals

11.56 A total of fifteen species of cetaceans has been recorded from Hong Kong waters (Parsons et al., 1995), of which only two species are resident year round: the Indo-Pacific Humpback Dolphin, also known locally as the Chinese White Dolphin (Sousa chinensis) and the Finless Porpoise (Neophocaena phocaenoides).

11.57 Both species are recognized internationally as of ecological importance and are listed in CITES Appendix I as well as “Data Deficient” in The IUCN Red List of Threatened Species. Furthermore, the Chinese White Dolphin is listed in China as a “Class 1 National Key Protected Species”, whereas the Finless Porpoise is listed as a “Class 2 National Key Protected Species” (AFCD, 2007).

Chinese White Dolphin (Sousa chinensis)

11.58 In Hong Kong, Chinese White Dolphins (Sousa chinensis) predominantly frequents the less saline brackish waters around the Pearl River Estuary although loss of habitat to numerous developments, fishing, shipping activity and pollution from various sources has reportedly placed increasing pressure on the local Chinese White Dolphin population (e.g. Liu and Hills, 1997; Jefferson, 2000a).

11.59 The most comprehensive and updated information on the population biology of the Chinese White Dolphin (Sousa chinensis) in Hong Kong waters is found in the “Monitoring of Indo-Pacific Humpback Dolphin (Sousa chinensis) in Hong Kong Waters” reports (Jefferson, 2005, Hung, 2007). Monitoring of the Indo-Pacific Humpback Dolphin has been ongoing annually since 1996. The monitoring work is commissioned by AFCD. A summary of the most recent sightings and distribution data is presented below.

Sightings and Distribution

11.60 Detailed sighting surveys were conducted from April 2006 to March 2007 to determine the abundance and the habitat use for Chinese White Dolphin, which reported their distribution mainly in those western waters influenced by the Pearl River Estuary. The most important habitats were assessed based on the highest concentrations of sightings. Most sightings were made to the west and north-west of Lantau Island. Some sightings were made at north-east Lantau and only very few sightings at southwest Lantau. One individual was sighted off south-east Lantau (Figure 11.8). No individuals were observed south of Hong Kong Island, in Western Buffer or Victoria Harbour WCZ (Hung, 2007)

11.61 Density varied dramatically among areas and seasons. By far, the highest density area was West Lantau, with high densities in all four seasons. Summer was the season with the highest density in West Lantau.. Dolphin sightings were concentrated in the waters around Lung Kwu Chau, near Black Point, around the Brothers Islands, Sham Shui Kok and the entire stretch of West Lantau waters from Tai O Peninsula to Fan Lau. In west Lantau dolphin densities were highest near Tai O Peninsula, Peaked Hill and Fan Lau (Hung, 2007)

Seasonal Variation and Abundance

11.62 Seasonal variation in dolphin distribution was evident during the study period (Figure 11.9). In South Lantau, dolphins only occurred in small numbers in winter and summer months. In West Lantau, number of dolphin sightings dropped significantly in spring months, and the dolphins were more evenly distributed in summer months than in autumn and winter months there (Figure 8). In North Lantau, seasonal variation in dolphin distribution was more prominent (Figure 9). In spring months, dolphins were found in very small number near Lung Kwu Chau, and were rarely observed in north-east Lantau waters. In summer months, dolphins were more widely distributed with regular occurrence in north-east Lantau waters especially around the Brothers and Sham Shui Kok. In autumn months, dolphin distribution shifted westward with a lot more sightings made within Sha Chau and Lung Kwu Chau marine park, with dolphins rarely occurring in north-east Lantau waters. In winter, dolphins continued to occur regularly around Lung Kwu Chau, and were only observed few times around the Brothers Island (Hung, 2007)

11.63 Previous data (Jefferson, 2005) indicates that abundance also varies extensively. The total of the estimates for Hong Kong waters was similar in three seasons (185 in winter, 190 in summer, and 207 in autumn). In spring, it dropped to only 91 individuals. In the Hong Kong survey areas, abundance was the lowest in spring in every case.

11.64 When all the seasonal totals for all the survey areas (in Hong Kong and China) were compared, the totals were very similar in three seasons (1171 in winter, 1076 in spring, and 1139 in autumn). Only in summer, was the total dramatically different, with the sum adding to only 678 individuals (Jefferson, 2005)

11.65 In summary, the total abundance estimates for all the survey areas (Hong Kong and China) during three of the four seasons (about 1080 -1170 in autumn through spring) is highly suggestive that the majority of the population was included in the estimates for these seasons. Therefore, the total population size should be about 1200-1300 individuals (Jefferson, 2005)

Calving Periods

11.66 Jefferson (2005) reported that analysis revealed some Chinese White Dolphin births occur in every month of the year but that there is a clear peak in spring and summer months (from March to August). During this half of the year, 76.3% of calves are born. A peak in calving during the warmer months of the year may be typical for the species (Cockcroft 1989).

11.67 Recent survey data (Hung, 2007) reports that there were totally 14 calves and 42 juveniles observed in the surveyed area from April 2006 to March 2007. Calves were mostly observed near Lung Kwu Chau Marine Park while juveniles were mostly observed along the west Lantau coastline. Some sightings of calves were also made near the Brothers Islands, and their distribution appears to be clustered to these 3 areas, i.e. Lung Kwu Chau, Brothers Islands and west Lantau). Over the past few years and indeed in the most recent survey west Lantau has the highest encounter rate for young calves indicating this is the most important habitat in Hong Kong for nursing activities.

Feeding Habits

11.68 Feeding habits of Chinese White Dolphin are analyzed based on post-mortem examination of stranding specimens. Croakers, Johnius sp., lionhead, Collichthis lucida, and anchovies Thryssa sp., were the most common prey. Little evidence shows that cephalopods or crustaceans are their major prey items (Parsons 1995).

Finless Porpoise (Neophocaena phocaenoides)

11.69 In Hong Kong waters, Finless Porpoises occur year round. These animals can be found primarily in the southern and eastern waters of the territory, and are also sighted in adjacent Chinese waters just south of Hong Kong (Jefferson and Braulik 1999; Jefferson et al., 2002a). The porpoises appear to avoid the western waters of Hong Kong, which are heavily influenced by freshwater input from the Pearl River, and are the major habitat of the humpback dolphin population (Jefferson et al., 2002a)

11.70 The most comprehensive and updated information on the population biology of the Finless Porpoises (Neophocaena phocaenoides) in Hong Kong waters is in “Monitoring of Finless Porpoise (Neophocaena phocaenoides) in Hong Kong Waters. Final Report submitted to the Agriculture, Fisheries and Conservation Department, HKSAR (Hung, 2005) Key baseline information based principally on surveys carried out from 1 November 2003 to 31 October 2005 is described below. Where more recent data was available the baseline data has been updated accordingly.

Abundance

11.71 According to the monitoring results in Hung (2005), ninety-eight groups of Finless Porpoises totaling 314 individuals were sighted during line-transect surveys (84 sightings) and helicopter sightings (14 sightings). Most of the porpoise sightings were recorded in Po Toi (36 sightings) and South Lantau (29 sightings) (Figure 11.10).

11.72 The most recent available data (Hung, 2007) recorded 39 sightings, totaling 139 finless porpoises during the 2006-2007 period (Figure 11.10)

Distribution

11.73 Sightings during Hung’s (2007) study were evenly distributed in Southwest Lantau (10 sightings), Southeast Lantau (11), Lamma (9), Po Toi (7) and Ninepins survey areas. The distribution pattern recorded during this survey (2006-2007) fits well with the historical distribution records of finless porpoise in Hong Kong from the past decade of porpoise monitoring (Figure 11.10)

Seasonal Variation (2003-2005)

11.74 Significant seasonal variation in porpoise distribution was recorded within Hong Kong waters. In winter and spring months (December to May), the majority of sightings were made off South Lantau and Lamma survey areas, while only a handful of sightings were made in eastern survey areas during these months. On the other hand, the distribution of porpoises noticeably shifted from southern waters to the eastern waters during summer months (June to August), this pattern remained more or less the same until autumn (September to November) when some porpoises gradually occurred off the southeastern part of Lantau Island and western part of Lamma Island. The season distribution is presented in Figure 11.11.

Calving Period

11.75 77% of finless porpoises are thought to be borne during the late autumn and early winter months of October to January.

Feeding Habits

11.76 More than 50% of the sightings with feeding behaviour were made near Ha Mei Tsui. Analysis of stomach contents of stranded animals revealed that Finless Porpoises in Hong Kong preyed on 25 species of fish, six species of cephalopods and one species of shrimp (Barros et al. 2002). Apogonidae, Sciaenidae, Engraulidae, Leiognathidae, and cephalopods species of the families Loligindae, Octopodidae and Seppiddae are the most important prey items. These prey species are primarily inshore, bottom-dwelling and mid-water species, suggesting that Finless Porpoises probably feed at different levels in the water column of nearshore habitats (Barros et al. 2002).

Cetacean Mortality in Hong Kong

11.77 Jefferson (2005) reported that the numbers of stranding of Chinese White Dolphin was about 6 to 14 per year in Hong Kong and most of the dolphins found stranding were neonates (less than 137 cm in length). In addition, the monthly pattern of strandings of neonates shows a large peak from May to August, which is partly a reflection of the seasonality of calving.

11.78 The cause of death of the cetaceans could be due to physical incidents and the effect of environmental contamination. Jefferson (2005) mentioned that in Hong Kong, of the 89 humpback dolphin strandings that were investigated, cause of death could only be determined with certainty for 10 specimens, although a possible cause of death was found for three others. Three specimens were diagnosed as having died from net entanglement, four from vessel collisions, one from debris (in this case, net) ingestion, one from a heart or brain pathology, and one from a bone infection. The report also mentioned the effect of contaminants to the health of cetacean. For example, recent study found that organochlorines interfere with reproductive capacity, cause immunosuppression, and have carcinogenic and teratogenic effects. In Hong Kong, organochlorine concentrations of humpback dolphin specimens are quite high, and DDT and PCB levels are higher than that in the finless porpoise population. However, due to very small sample size for tissue analysis, it is unlikely to assume that contaminants would cause either chronic or acute effects for cetacean from a proved scientific statistical analysis. The cause of stranding in the finless porpoise is also not understood as most stranding specimens were recovered after decomposition had made cause of death impossible to determine.

Green Turtle (Chelonia mydas)

11.79 Five species of sea turtle have been recorded in local waters, including the Green Turtle, Hawksbill, Leatherback, Loggerhead and Olive Ridley. Some of the records are of live sightings, while others are from the stranding of dead specimens. Most local records are of the Green Turtle, the only species of sea turtle that breeds in Hong Kong.

11.80 Green Turtles are listed in Appendix l of the CITES and the Bonn Convention, indicating the international recognition and agreement to protect this highly endangered species. In Mainland China, Green Turtles are listed as a Class II Protected Animal in the List of State Key Protected Wildlife in China, giving the animal a national protection status against hunting and commercial exploitation. A detailed description of Green Turtle is presented below based on “Green Turtles in Hong Kong (Chan 2004)”.

11.81 It has been observed that the number of nesting females has declined significantly in the last few decades in many parts of the world. This has led to concern about the survival of the species, and hence the international efforts to protect the Green Turtle. Sham Wan in Hong Kong and Gangkou National Nature Reserve for Sea Turtles, are among the few remaining nesting sites for sea turtles along the coast of South China.

11.82 The sea turtles used to nest on remote beaches of Hong Kong, for example, Lamma Island (Tung O and Ha Mei Wan), Lantau Island (Tong Fok Miu Wan and Tai Long Wan) and Hong Kong Island (Shek O and Tai Tam Bay). However, due to rapid urban and rural development, and human activities around these areas, sea turtles no longer nest there today. Sham Wan, on Lamma Island, is now the only Hong Kong site in which a small population of Green Turtles is known to nest regularly. In addition to some sporadic and incomplete historical records, regular nesting of Green Turtles at Sham Wan beach has been recorded in recent years.

11.83 The Sham Wan nesting beach and its nearby shallow waters were made a Site of Special Scientific Interest (SSSI) in June 1999 in recognition of ecological value and scientific importance. The SSSI should be protected against disturbance and encroachment by development. Only a few listed uses, essential to sustain the site or conducive to the conservation or education purposes, are permitted. To avoid or minimize human disturbance to the Green Turtle nesting site, the sandy beach at Sham Wan was gazetted as a Restricted Area, under the Wild Animals Protection Ordinance in July 1999.

11.84 The major threats against the Green Turtle include: loss of suitable nesting sites as a result of coastal development, disturbance from human activities (e.g. artificial illumination and noise), marine pollution, debris washed ashore hindering the movements of egg-laying females and emerging hatchlings, incidental capture in fishing gear, injury from boat propellers, and poaching of eggs.

Horseshoe Crabs

11.85 Horseshoe crabs are an ancient and taxonomically isolated group (Class Merostomata, sub-class Xiphosura) related to spider, ticks and mites. They are important in biomedical applications where the blood of horseshoe crabs is the source of compounds used to screen for pathogens in medical facilities and on medical equipment. Three species have previously been reported to occur in HKSAR waters, Tachypleus tridentatus, T. gigas and Carcinoscorpius rotundicauda. However recent work (Shin et al., 2007) only reported two species, T. tridentatus and C. rotundicauda. Information gathered on distribution and abundance of these species in Hong Kong is summarised below as reported by Shin at al. (2007).

Distribution

11.86 Random quadrat sampling along shore transects at 17 survey sites in Hong Kong recorded a total of 15 juvenile T. tridentatus distributed among Tsim Bei Tsui, Pak Nai, Ha Pak Nai in northwestern New Territories, and San Tau and Yi O on Lantau Island. No C. rotundicauda were recorded in this transect study at the 17 sites. However additional walk-through observations on the shores revealed the presence of T. tridentatus at Sheung Pak Nai in Northwestern New Territories, and Shui Hau Wan, Tai Ho Wan, Sham Wat and Tung Chung on Lantau Island, and C. rotundicauda at Tai Ho Wan on Lantau Island and Luk Keng and Lai Chi Wo in Northeastern New Territories.

11.87 Intensive distribution surveys were also carried out at four important horseshoe crab nursery grounds, Pak Nai, Ha Pak Nai, Shui Hau Wan and San Tau at monthly intervals between March and August 2005. All sites supported T. tridentatus with the maximum total abundance of 86 individuals recorded at Shui Hau Wan. Few individuals of C. rotundicauda were also observed at Pak Nai and Ha Pak Nai, while a higher abundance (64 individuals) were recorded at San Tau on Lantau Island. Overall population of C. rotundicauda was comparatively lower than that of T. tridentatus.

11.88 The distribution of horseshoe crabs in open waters was assessed through interview studies with local fishermen. 332 individuals were reportedly caught in Hong Kong waters from, eastern waters, such as Sai Kung, Tseung Kwan O and Kwo Chau Wan; western waters near Pak Nai, Lung Kwu Tan and Tuen Mun; southern waters, around Cheung Chau, Shek Kwu Chau and Ping Chau; and Lantau Island waters near Tung Wan, Shek Pik, Cheung Sha and Chok Ko Wan (Tai Siu A Chau).

11.89 The locations where horseshoe crabs were either observed or recorded during the study period are shown in Figure 11.12

Marine Park, Marine Reserve and SSSIs

Sha Chau and Lung Kwu Chau Marine Park

11.90 The Sha Chau and Lung Kwu Chau Marine Park is situated in open waters on the western side of Hong Kong. This marine park was designated mainly for Chinese White Dolphins since 22 November 1996. It covers a total sea area of about 1,200 hectares.

11.91 The marine environment of Sha Chau and Lung Kwu Chau Marine Park is greatly influenced by the Pearl River freshwater run-off, with high organic loading and sediment loading. Marine organisms found in this region are highly adapted to a low salinity and highly turbid marine environment.

11.92 Sha Chau and Lung Kwu Chau Marine Park has rich fisheries resources. Fishes of the Engrulidae, Scieanidae and Clupeidae families are important food for Chinese White Dolphin which are commonly found in this marine park. It therefore provides an important feeding ground for the dolphins.

Marine Reserve

11.93 The Cape D' Aguilar Marine Reserve was designated on 5 July 1996. It lies in the southeastern tip of Hong Kong Island. The total sea area of this marine reserve is about 20 hectares.

11.94 The biodiversity is rich in this Marine Reserve, including numerous kinds of hard corals, soft corals, gorgonian and marine invertebrates. In order to protect these important habitats, water sports and coastal activities are not allowed.

SSSIs

11.95 The Shek O Headland SSSI is located about 8km south of Junk Bay. This exposed rocky shore habitat was designated a SSSI in February 1998 because it is among the areas with the richest assemblages of macroalgae (seaweed) in Hong Kong.

11.96 In 1991 the Cape D' Aguilar area was designated a SSSI in recognition of the growing interest in understanding and conserving Hong Kong's marine environment.

11.97 Sham Wan was designated as a SSSI as it provides nesting site for Green Turtles.

11.98 San Tau Beach is designated as an SSSI as it is the only known location on Lantau that supports both the seagrass species Halophila ovalis and Zostera japonica. This SSSI is also known for the diverse mangrove/ mangrove associated communities that it supports.

Artificial Reefs

11.99 There are two artificial reefs within the Assessment Area, one at Sha Chau and one near the International Airport. The goal of the artificial reefs was to enhance marine resources, rehabilitate degraded habitats, protect spawning and nursery ground for marine life and enhance the overall quality of seabed habitat.

Ecological Value

11.100 Based on the results from the water quality modeling (Section 6), predicting changes in DO, Salinity and Temperature etc., resulting from the operational stage of HATS Stage 2A, only a highly localised area surrounding the SCISTW outfall will be impacted. The impacted areas are restricted to waters within Victoria Harbour and Western Buffer WCZs. No significant adverse impacts on species/sites of conservation importance identified above are expected outside of this impact area. Therefore the following assessment focuses on ecological resources within the Victoria Harbour and Western Buffer WCZs.

11.101 It should be noted that exceedances of Total Inorganic Nitrogen (TIN) and Orthophosphate do occur in Southern and North Western WCZs which are outside the impact areas stated above. These WCZs are not included in the following assessment because water quality modeling predicts similar levels of these nutrients with and without implementation of the project. Additionally, the ambient nutrient levels of Southern and North Western WCZ already exceed the relevant WQO/WQC. This suggests that exceedances of WQO/WQC for these nutrients are likely due to non-HATS sources and not a result of operation of the project.

11.102 With reference to the baseline conditions described above, the ecological values of these two WCZs are assessed using criteria in EIAO TM Annex 8 and presented in Tables 11.12 to 11.15. Species of conservation importance identified within the potential impacted areas include various coral species and the Chinese White Dolphin, Sousa chinensis.

Table 11.12 Ecological Value of Soft Bottom Community in Potential Impacted Areas (Victoria Harbour and Western Buffer WCZs)

Criteria	Benthos
Broad area of potential impact	Western Buffer	Victoria Harbour
Naturalness	Benthic habitats have been subject to anthropogenic disturbance from urban developments and are under the influence of water pollutants from Pearl River and Hong Kong urban discharges.	Benthic habitats have been subject to high degree of disturbance from urban developments and are under the influence of water pollutants from Hong Kong urban discharges, as well as Pearl River discharges.
Size	Moderate large.	Moderate.
Diversity	Species richness is low (d< 10) and diversity is low (H’<3).	Species richness is low (d< 10) and diversity is low (H’<3).
Rarity	All species recorded are common and widespread in Hong Kong.	All species recorded are common and widespread in Hong Kong.
Re-creatability	Moderate, as habitats have been subject to medial disturbance.	High, as habitats have been subject to high level of disturbance.
Ecological linkage	No. They are not linked to other high value habitats.	No. They are not linked to other high value habitats.
Potential value	Low	Low
Nursery/breeding area	Possible but none documented.	Possible but none documented.
Age	N.A.	N.A.
Abundance	Low	Low
Ecological Value	Low	Low

Table 11.13 Ecological Value of Intertidal Community in Potentially Impacted Areas (Victoria Harbour and Western Buffer WCZs)

Criteria	Intertidal
Broad area of potential impact	Western Buffer	Victoria Harbour
Naturalness	The coastline along Western Buffer contains a range of habitats from disturbed habitats such as artificial seawall (e.g. in Tsing Yi Island), and gazetted beaches (e.g. in Lido, Ting Kau), to natural rocky shores (e.g. in Sandy Bay).	The coastline along the Victoria Harbour is not natural. The coastline is straightened with concrete lining and artificial seawalls.
Size	Moderate size of intertidal habitats in Western Buffer WCZ.	Relatively large as many artificial seawall habitats.
Diversity	Diversity and species richness is low.	Mainly biofouling species. Diversity and species richness is very low
Rarity	Low as habitats support common and widespread species in Hong Kong.	Low as species are generally bio-fouling species common and widespread in Hong Kong.
Re-creatability	Habitat can be recreated for sandy shore and artificial seawall. For natural rocky shore, it takes long time to allow species re-colonization.	Habitat can be recreated as most of the areas are artificial seawalls.
Ecological linkage	No. They are not linked to other high value habitats.	No. They are not linked to other high value habitats.
Potential value	Low	Negligible.
Nursery/breeding area	Possible but none documented	Possible but none documented
Age	N.A.	N.A.
Abundance	Low	Low
Ecological Value	Low	Low

Table 11.14 Ecological Value of Coral Community in Potentially Impacted Areas (Victoria Harbour and Western Buffer WCZs)

Criteria	Corals
Broad area of potential impact	Western Buffer	Victoria Harbour
Naturalness	Benthic habitats have been subject to certain degree of disturbance from urban developments and are under the influence of water pollutants from Pearl River and Hong Kong urban discharges.	Benthic habitats have been subject to high degree of disturbance from urban developments and are under the influence of water pollutants from Hong Kong urban discharges, as well as Pearl River discharges.
Size	Small to moderate. Soft corals recorded south of Tsing Yi. Soft and hard corals recorded at Ap Lei Chau and Sandy Bay	Small. Corals only recorded at Green Island which is on the border of Victoria Harbour and Western Buffer.
Diversity	Low diversity of soft corals were recorded at south of Tsing Yi. At Ap Lei Chau low soft coral diversity and moderate-high hard coral diversity were recorded. Sandy Bay had low soft coral diversity and moderate high hard coral diversity.	No hard coral was recorded in Green Island and soft corals and gorgonians were of low diversity.
Rarity	No rare species were recorded.	No rare species were recorded.
Re-creatability	Low. It takes long years for re-colonization.	Low. It takes long years for re-colonization.
Ecological linkage	No. They are not linked to other high value habitats.	No. They are not linked to other high value habitats.
Potential value	Low	Low
Nursery/breeding area	Possible but none documented.	Possible but none documented.
Age	N.A	N.A
Abundance	Low-moderate. Low abundance was recorded in Tsing Yi and Ap Lei Chau, but moderate abundance in Sandy Bay.	The soft corals recorded in Green Island were abundant.
Ecological Value	Low-moderate	Low

Table 11.15 Ecological Value of Chinese White Dolphin in Potentially Impacted Areas (Victoria Harbour and Western Buffer WCZs)

Criteria	Chinese White Dolphin
Protection status	Protected under the Wild Animals Protection Ordinance (Cap. 170); The Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586) and Marine Park Ordinance (Cap. 476) and Chinese White Dolphin is listed in CITES Appendix 1 and protected in the PRC.
Distribution	No records of Chinese White Dolphin were made from Victoria Harbour WCZ and less than 3 individuals per 100 km^2 were recorded in Western Buffer WCZ within 3 years surveying effort between 2002-2005 (Jefferson, 2005). The latest monitoring report (Hung, 2007) recorded no sightings of Chinese White Dolphin in the potentially impacted area during the 2006-2007 period. Victoria Harbour and Western Buffer WCZs are therefore not considered as important habitat for the Chinese White Dolphin.
Rarity	Locally common with over 1000 individuals reported from the Pearl River and Hong Kong waters.

Identification of Environmental Impacts

Construction Phase

11.103 During the upgrading works to existing PTWs at North Point, Wan Chai East, Central, Sandy Bay, Cyberport, Wah Fu and Ap Lei Chau, no direct impacts on marine ecological resources are expected as no marine works would be involved. However indirect impacts on water quality may arise as a result of site run-off, sewage from workforce, accidental spillage and discharges of wastewater from land based construction activities.

11.104 The pipeline connecting the PTWs to SCI will be constructed by deep tunneling below the sea bed. The tunnel would be constructed from a terrestrial based access point and therefore pipeline construction would not cause any disturbance to the seabed. Thus, no direct impact on marine ecological resources as a result of pipeline construction is expected.

11.105 Although no marine works are involved during the upgrade of the majority of PTWs, a small area of seawall (approx. 50m) would be demolished and reconstructed at the Aberdeen PTW site to complete the construction works. As confirmed by dive surveys, the subject site supported very limited marine life. Only 3 colonies of a common hard coral species (Oulastrea crispata), all in small size (3 to 5cm) and of low coverage were found in the potentially affected area (Figure 11.13). The corals in this area have a low ecological value due to the sparse cover, small size, low diversity and commonness of the coral found. However as the corals located in the direct impact area are attached to moveable boulders < 50cm in diameter it is suggested to translocate these corals to a nearby suitable habitat so as to avoid/minimise this impact.

11.106 Planned temporary bypass of sewage effluent via seawall or submarine outfalls of SCISTW and individual PTW would be required during the construction stage, and immediately prior to and/or during the early phase of the commissioning of the upgraded SCISTW and PTW. The temporary sewage bypass would cause transient increase of pollution levels in the receiving marine water. The potential impact of pollutants contained in sewage effluent on marine ecological resources is discussed below.

Operational Phase

11.107 Key parameters of concern relating specifically to the disinfection process would include total residual chlorine (TRC) and chlorination by-products (CBPs), E. coli, and dissolved oxygen (DO). The formation of TRC and CBPs in the Project effluent would be due to chlorination and dechlorination of the sewage effluent. The changes of E. coli in the Project would be a result of the effectiveness of proposed disinfection process. The potential oxygen depletion impact would be related to the dechlorinating agent used.

11.108 TRC and CBP which are toxic and persistent in nature could cause formation of mutagenic/carcinogenic and toxic by-products within organisms negatively impacting marine life (Monarca et al., 2000). At sub-lethal levels toxicity may include alteration of physiology of organisms e.g. foot activity and byssus production and filtration rate of mussels (Rajagopal et al., 2003). The potential impacts of acute and chronic toxicity to fish and marine mammals from the potentially harmful products within the disinfected effluent are addressed in detail under the Ecological Risk Assessment in Section 8.

11.109 E. coli contains many strains and not all strains are toxic in nature to marine organisms. There are pathogenic strains which would potentially adhere to the gill surfaces and cause mortality of fish species (Yin et al., 2006). Some marine organisms e.g. fish, may become aggressive when they are stimulated by pathogens (Efthimiou et al., 1994). However, not all the marine organisms would suffer from adverse impacts associated with pathogenic strains of E. coli. Hang et al. (2002) showed that during in-vitro tests, most marine organisms including crustacean species would induce anti-bacterial enzyme or chemicals within their haemolymph, cephalothorax, exoskeleton and gills as a body defence against pathogenic strains of E.coli.

11.110 Other environmental impacts associated to the HATS Stage 2A operational phase mainly involve changes in water quality arising from the effluent discharged. These impacts are long term and the severity of their nature depends largely on existing and future hydrographical parameters of the water bodies surrounding SCISTW outfall diffuser.

11.111 An increase in nutrient levels (eutrophication) such as Total Inorganic Nitrogen (TIN) and Orthophosphate can be caused by the discharge of sewage effluent at the SCISTW outfall. Elevations of nutrients like nitrates and phosphates can potentially lead to algal blooms. Certain Harmful Algal Bloom (HAB) species can produce toxins that are harmful to marine organisms but only a minority of blooms consist of species that synthesize toxins. Current scientific knowledge on the growth of HAB species and the conditions leading to their development, is insufficient to be able to predict when and where such events will occur (Landsberg, 2002).

11.112 Eutrophication can lead to hypoxia by stimulating algal blooms which decompose in the bottom of the water column and consume large amounts of oxygen. Hypoxia in the water column (DO < 2.8 mg O₂/L; as defined by Diaz and Rosenberg, 1995) can lead to mortality of benthic fauna. If dissolved oxygen reaches critically low levels marine benthic organisms may suffocate and die. If levels of DO are reduced to a low but sub-lethal level, many organisms can survive by increasing their ventilation rate and volume. However the increase in oxygen consumption rate is metabolically demanding and would reduce the energy available for other vital processes (Valverde et al., 2006).

11.113 Eutrophication is also recognized as a major cause of coral reef mortality (Ginsburg, 1993) for a number of reasons. Firstly, increased nutrient levels can decrease coral growth by favouring the growth of competing macro algae, thus introducing intense competition for light and substrate for the slower growing corals. Nutrients may also result in phytoplankton blooms, which in turn will reduce light penetration into the water column and inhibit photosynthesis of symbiotic zooxanthellae. Thirdly, eutrophication may lead to algal blooms with associated problems as described above.

11.114 To avoid direct detrimental effects on marine benthic communities and coral communities, nutrient levels should not exceed 3 mg/L Phosphate and 18 mg/L Nitorgen (Herbert et. al, 1992). For reference, following the HATS EEFS, this project applies much stricter mixing zone nutrient criteria for TIN and Orthophospahte of 0.4 mg/L and 0.04 mg/L, respectively.

11.115 Some fish species may be attracted to effluent discharge and if this increase in potential prey is significant enough, it may in turn attract cetaceans to sewage outfalls (Montgomery and Watson, 1999). However treatment processes will result in reduction of potentially toxic substances, such as ammonia and most metals, in sewage effluent, so the direct/indirect risks to dolphins and porpoises are low.

11.116 Another potential indirect affect on cetaceans is low DO affecting the distribution and abundance of their prey. Marine mammals will not avoid an area of low DO as they breathe air. However, if conditions become hypoxic or anoxic, they will avoid these highly unfavorable conditions.

11.117 Discharge of sewage effluent which is often of significantly lower salinity than seawater can potentially lower the salinity of receiving water. Salinity fluctuation in coastal waters causes disruption to the normal physical processes of diffusion and osmosis in marine organisms and requires them to adapt to new conditions to survive. Mechanisms of adaptation to changing osmotic and ionic conditions vary widely among marine organisms, but almost all have a safe range in which they can survive. If salinity varies above or below this adaptable range, high mortality and poor growth and breeding may occur.

11.118 Hard corals in general are not tolerant to salinities differing from the range of normal seawater. Following this, the distribution of corals in Hong Kong is limited by salinity (AFCD, 2002). The particular coral species found in Western Harbour areas and in the east Lamma Channel suggests that these species can tolerate salinity down to 25 ppt. If salinity is reduced further by fresh water discharge from SCI diffuser it may threaten the survival of these corals. However, because of the high initial dilutions at the SCISTW outfall, this impact is expected to be insignificant.

11.119 Discharge of sewage effluent can also potentially change the temperature of surrounding seawater and cause direct impacts to marine organisms as seawater temperature is often the most important environmental factor affecting these organisms. Temperature regulates the metabolic rate, and thereby influences the feeding, growth, metabolism, reproduction, larval development and distribution of marine organisms. Hong Kong’s sea temperature ranges from 15 to 30˚C, depending mainly on the degree of vertical mixing and the predominant oceanic currents. Temperature can also effect hard corals which only tolerate a narrow range. Corals do not develop properly where mean annual sea temperature is < 18˚C. Due to the high initial dilution factor at the SCISTW outfall, change in seawater temperature is expected to be insignificant.

11.120 Emergency discharge of preliminarily treated effluent may be required during heavy rainfall events or during equipment/power failure Heavy rain would potentially result in the need for emergency discharge via seawall bypass at SCISTW and all PTWs when inflow exceeds the capacity of the system. Emergency discharge would also occur during equipment/power failure at PTWs or SCISTW. If equipment/power failure occurs at SCISTW then preliminary treated sewage effluent would be discharged from all PTWs. If power/equipment failure occurred at an individual PTW then raw sewage would be discharged into the receiving water body via the seawall bypass of the same PTW. Emergency discharge of preliminarily treated sewage would cause a temporary deterioration in water quality in the receiving water body and have potential adverse impacts on marine ecological resources as described above.

11.121 There are a number of concurrent projects in the vicinity of the Project boundaries (refer to Section 2.32, Table 2.3). However, no dredging or filling activity is proposed in the vicinity of the proposed marine work area at Aberdeen PTW. Therefore no cumulative impact on deterioration of water quality and the associated marine ecological resources is expected.

Evaluation of Environmental Impacts

Construction Phase

11.122 Indirect impacts on water quality would potentially arise from land based construction activities. Sediment/ pollution laden site run-off, sewage from workforce, accidental spillage and discharges of wastewater entering the marine environment would potentially cause a deterioration in water quality which may have subsequent adverse impacts on marine ecological resources. Standard good site practice and the implementation of mitigation measures, proposed in Water Quality Section 6, such as the use of silt/sediment and grease traps, effective site drainage, and provision of chemical toilets would minimise any adverse impacts to the marine environment resulting from land based construction activities. Thus no significant adverse impact is expected.

11.123 Subtidal surveys carried out at the seawall at Aberdeen PTW indicated there would be direct loss of a small number of coral colonies during the demolition and re-construction of the seawall. The coral found at this site was Oulastrea crispata which is a common species found across Hong Kong waters. Owing to the sparse cover, small size, low species richness and commonness of the coral found, the marine habitat of this survey site is considered to have a low ecological value. Only three colonies were identified in the directly impacted area and all were attached to small moveable boulders < 50cm in diameter, thus translocation is suggested to avoid/minimise this impact.

11.124 No significant indirect adverse impacts are expected on water quality as a result of seawall reconstruction at Aberdeen PTW as no dredging will take place and silt curtains or sheet piles will be used to prevent potential spread of filling material during re-construction.

11.125 Planned temporary bypass of sewage via seawall or submarine outfalls of SCISTW and individual PTW would be required during the construction stage, and immediately prior to and/or during the early phase of the commissioning of the upgraded SCISTW and PTW. This would lead to an increased level of E, coli and other sewage derived microorganisms in the receiving water body. It should be noted that the planned discharge would last 2 weeks, as the worst case scenario. Water quality modelling has shown that the level of E. coli in the receiving water bodies would fluctuate highly on a daily basis during this period. As most marine organisms including crustacean species would induce anti-bacterial enzyme or chemicals within their haemolymph, cephalothorax, exoskeleton and gills as a body defence against pathogenic strains of E.coli. (Hang et al., 2000) and deterioration in water quality would be transient, no significant adverse impact on marine ecological resources is expected from the planned temporary bypass of sewage.

Operational Phase

11.126 The predicted oxygen depletion is predicted by water quality modeling to be restricted to Western Buffer WCZ and Victoria Harbour WCZ. DO depletion levels at the SCISTW outfall were predicted to be highest in the wet season at 0.028 mg/L, in the initial and intermediate operation years of HATS Stage 2A. It would be expected that the actual levels would be smaller as it was predicted as a worst case scenario. Also this depletion of oxygen was measured in a 120m x 140m grid cell, in the adjacent cell oxygen depletion is less than half this figure so oxygen depletion should be considered insignificant. Such slight decrease in DO level localized at the SCISTW outfall would not pose significant impacts to marine benthic communities in Western Buffer and Victoria Harbour WCZs. Overall the model results indicated that implementation of HATS Stage 2A would improve the DO levels in the Victoria Harbour, Eastern Buffer and Junk Bay WCZs.

11.127 Water quality models for HATS Stage 2A indicate that there are exceedances of WQO and WQC for TIN and Orthophosphate (PO4) in the assessment area, in Western Victoria Harbour, Southern and North Western WCZ. The exceedances of TIN and Orthophosphate concentrations could potentially lead to increased algal activity but the increased concentrations predicted are much lower than guidelines identified that could directly impact benthic communities, i.e. 3 mg/L Phosphate and 18 mg/L Nitrogen (Herbert et al., 1992). It is important to note here that the model predicts similar levels of these nutrients with and without implementation of the project. Additionally, the ambient nutrient levels of western Victoria Harbour, Southern and North Western WCZ already exceeded the relevant WQO, suggesting that exceedances of these nutrients are due to non-HATS sources, such as the Pearl River. (See also Water Quality Section)

11.128 The incidence of Red Tides has not increased since HATS Stage 1 was commissioned in 2001, and in-fact the majority of Red Tide Events in 2005 are reported in Eastern waters where nutrient levels are the lowest in Hong Kong. A recent report suggested that the threshold nutrient level for algal blooms in Hong Kong would be 0.12 mg/l and 0.018 mg/l for N and P respectively (Wong et al., 2007). In the western waters (Victoria Harbour, Western Buffer, North Western and Deep Bay), the ambient nutrient levels are therefore potentially high enough to trigger algal blooms. However, algal blooms have seldom been observed in these waters possibly due to the fact that the water flushing effect and vertical mixing in these areas is relatively strong. The lack of algal blooms in these waters suggests that the occurrence of algal blooms is a dynamic process not limited by a single factor such as nutrient levels. Despite this it is widely agreed that excessive nutrients, while not necessarily critical do play an important role in the occurrence of algal blooms. Past water quality monitoring records indicate that N is much more abundant than P in the Assessment Area, and therefore P would be the most limiting factor should other algal bloom criteria be met. Although enhancing P removal for HATS Stage 2A would generally reduce the PO4 level in the Assessment Area, the reduction was predicted to be small, and since algal blooms are natural phenomena which could occur in unpolluted water with low nutrient content under the right environmental condition, adopting the enhanced P removal would not necessarily have a significant effect in reducing the red tide occurrence (For a detailed discussion see Water Quality Section 6). Besides, the enhanced P removal would have the environmental disbenefits in collecting, handling and disposal of increased quantities of sludge produced due to higher P removal efficiencies. It is therefore concluded that the enhanced P removal would not be an effective treatment option for the HATS Stage 2A in minimizing the environmental impact.

11.129 The discharge of treated effluent at SCISTW outfall will increase from 1.55 M m³/day to 2.45 M m³/day after implementation of HATS 2A. Based on water quality model predictions, the dilution effects on salinity will be highly visible within approx. 100m (Zone of Initial Dilution – ZID) of the outfall diffuser with an average dilution of 60:1. With a typical effluent salinity of 10 ppt and an ambient salinity of 30 ppt, the average decrease in salinity at the edge of the ZID will be approximately 0.3 ppt. Thus, any negative impacts due to salinity will be highly localized. For similar reasons, temperature effect will also be minimal and highly localised. Therefore no adverse impacts on benthic or coral communities are expected.

11.130 Near-field water quality modeling results show that unionized ammonia is diluted to a level in compliance with water quality criteria at the edge of the ZID and thus no adverse impact on benthic communities or marine mammals is expected. No adverse impact on sea turtles is expected due to the far distance between the SCI diffuser and the turtle nesting site (>20km). In general, the unionized ammonia levels would be improved in the North Western, Western Buffer and Victoria Harbour WCZ after commissioning of Stage 2A.

11.131 Emergency discharge of sewage effluent at PTW and SCISTW may occur during periods of heavy rain when inflow exceeds the capacity of the system or as a result of power/equipment failure. This would result in a rise in the level of E. coli in the receiving water body and thus a subsequent deterioration in water quality which would potentially cause adverse impacts to marine ecological resources. Water quality modelling showed that pollution levels for parameters such as nutrients and DO were not predicted to be adversely affected by emergency discharges. Additionally modelling predicted that increases in the level of suspended sediment resulting from emergency discharges would not exceed the assessment criterion of 100g/m²/day at coral sites (See Appendix 6.5). Water quality is predicted to return to normal condition 1 to 2 days after emergency discharges. Due to the highly transient nature of potential emergency discharges and the ability of marine organisms to naturally resist pathogenic strains of E. coli (Hang et al., 2000) only minor and acceptable adverse impacts are expected on marine ecological resources. For a detailed discussion of the modelling results associated with emergency discharges of sewage effluent via seawall bypass associated with heavy rainfall or equipment/power failure, see Water Quality Section 6, Para. 6.280-6.311.

11.132 Water quality modelling predicts that no exceedance of WQO/WQC would occur at coral sites within the assessment area during normal operation of the project or emergency discharge situations.

11.133 Based on the above, in accordance with the EIAO TM Annex 8 criteria, the potential ecological impacts on marine benthic community, coral community, intertidal community and Chinese White Dolphin are presented in Tables 11.16 to 11.19. The potential ecological impacts on Green Turtle and Finless Porpoise are not tabulated below as they are not recorded from the potentially impacted areas, Victoria Harbour WCZ and Western Buffer WCZ, and therefore no adverse ecological impacts are anticipated.

Table 11.16 Potential Ecological Impacts on Benthos Habitats Within Potential Impacted Areas (Victoria Harbour and Western Buffer WCZs)

Criteria	Western Buffer WCZ	Victoria Harbour WCZ
Habitat quality	Low	Low
Species	Dominant species are polychaetes and crustaceans, which are common and widespread in Hong Kong	Dominant species are polychaetes and crustaceans, which are common and widespread in Hong Kong
Size/ Abundance	Moderate size of benthic habitat would be impacted	Moderate size of benthic habitat would be impacted
Duration	Long term	Long term
Reversibility	No	No
Magnitude	Low. Small localized change of DO, Salinity and Temperature at SCISTW outfall and resulting ecological impacts would be insignificant. Increases in TIN and Orthophosphate concentration may cause HABs	Low. Small localized change of DO, Salinity and Temperature at SCISTW outfall and resulting ecological impacts would be insignificant. Increases in TIN and Orthophosphate concentration may cause HABs
Potential Impact	Low	Low

Table 11.17 Potential Ecological Impacts on Coral Community Within Potential Impacted Areas (Victoria Harbour and Western Buffer WCZs)

Criteria	Western Buffer WCZ	Victoria Harbour WCZ
Habitat quality	Low- Moderate	Low-moderate
Species	Few soft coral species were recorded in waters south of Tsing Yi and no hard coral species were recorded in Tsing Yi. The diversity of soft coral species recorded in Sandy Bay and Ap Lei Chau were low. Moderate-high number of hard coral taxa (>14 taxa) were recorded in Ap Lei Chau and Sandy Bay.	Only Green Island within this WCZ had records of soft coral and they were of low diversity. Green island is situated on the border or Victoria Harbour and Western Buffer WCZ.
Size/ Abundance	Low abundance of soft coral and no hard coral communities were recorded south of Tsing Yi. Low abundance of both soft and hard corals was recorded in Ap Lei Chau. Moderate high abundance of soft corals and low abundance of hard corals were recorded in Sandy Bay	The soft corals recorded in Green Island were abundant
Duration	Long term	Long term
Reversibility	No	No
Magnitude	Low. Small localized change of DO, Salinity and Temperature at SCISTW outfall and resulting ecological impacts would be insignificant. Increases in TIN and Orthophosphate concentration may cause HABs	Low. Small localized change of DO, Salinity and Temperature at SCISTW outfall and resulting ecological impacts would be insignificant. Increases in TIN and Orthophosphate concentration may cause HABs
Potential Impact	Low	Low

Table 11.18 Potential Ecological Impacts on Intertidal Communities Within Potential Impacted Areas (Victoria Harbour and Western Buffer WCZs)

Criteria	Western Buffer WCZ	Victoria Harbour WCZ
Habitat quality	Low	Low
Species	The dominant species of herbivorous grazers and limpets are common and widespread in Hong Kong	The dominant species would be the bio-fouling organisms and are common and widespread in Hong Kong
Size/ Abundance	Low abundance of species recorded	Low species diversity, moderate area
Duration	Long term	Long term
Reversibility	No	No
Magnitude	Low. Small localized change of DO, Salinity and Temperature at SCISTW outfall and resulting ecological impacts would be insignificant. Increases in TIN and Orthophosphate concentration may cause HABs	Low. Small localized change of DO, Salinity and Temperature at SCISTW outfall and resulting ecological impacts would be insignificant. Increases in TIN and Orthophosphate concentration may cause HABs
Potential Impact	Low	Low

Table 11.19 Ecological Impact on Chinese White Dolphin Within Potential Impacted Areas (Western Buffer and Victoria Harbour WCZs)

Criteria	Chinese White Dolphin
Habitat quality for Victoria Harbour and Western Buffer WCZs	The habitats have already been subjected to disturbance from urban developments and are under the influence of water pollutants from Pearl River and Hong Kong urban discharges
Species	Chinese White Dolphin is an ecologically important species listed under IUCN Red List of Threatened Species, CITES Appendix 1 and protected Animals under Hong Kong Legislation and in the People Republic of China
Size/ Abundance	No records of Chinese White Dolphin were made from Victoria Harbour WCZ and less than 3 individuals per 100 km2 were recorded in Western Buffer WCZ within 3 years surveying effort between 2002-2005 (Jefferson, 2005). The latest monitoring report (Hung, 2007) recorded no sightings of Chinese White Dolphin in the potentially impacted area during the 2006-2007 period
Duration	Long term
Reversibility	No
Magnitude	Low. Small localized change of DO, Salinity and Temperature at SCISTW outfall and resulting ecological impacts would be insignificant. Increases in TIN and Orthophosphate concentration may cause HABs.
Potential Impact	Low

11.134 The existing SCISTW outfall location was chosen specifically to be in an area with low value ecological resources. No significant adverse ecological impacts are anticipated during operation of the Project because:

· Disinfection process will result in improvement of water quality with reduction in E. coli levels in Western Buffer WCZ and western Victoria Harbour WCZ;

· Only localized and small changes in TRC, CBPs and DO around the existing SCISTW outfall;

· No unacceptable ecological risk on marine mammal and marine life in relation to acute and chronic effects;

· Water quality criteria for unionized ammonia is met at the edge of the ZID and this is out of the normal distribution range of dolphins, porpoises and green turtles;

· Unionized ammonia levels would be improved in the North Western, Western Buffer and Victoria Harbour WCZ;

· Oxygen depletion is minimal and highly localized around the SCISTW outfall;

· Improved DO levels in the Victoria Harbour, Eastern Buffer and Junk Bay WCZs;

· Highly localised salinity and temperature changes would not have adverse impacts on the ecological habitats identified;

· Increases in the levels of TIN and Orthophosphate predicted are not significant enough to have direct impacts on identified ecological communities;

· There is no documented data on the specific conditions leading to HABs and they have been documented in polluted and un-polluted water. Increases in nutrient levels during discharge of sewage effluent would be unlikely to trigger HAB events;

· TIN and Orthophosphate levels have increased in the Assessment Area since the implementation of HATS Stage 1, but no increase in the number of HAB events has been observed;

· Water quality modelling predicts little difference in levels of TIN and Orthophosphate with or without the implementation of the project. Additionally, with the implementation of HATS Stage 2B, TIN and phosphate discharge will be reduced;

· Western Buffer WCZ and western Victoria Harbour WCZ, the areas affected by the effluent, generally support low to moderate ecological resources;

Mitigation of Environmental Impact

11.135 According to EIAO-TM Annex 16, ecological impacts on habitats and the associated wildlife, especially on those important habitat and species of conservation importance, caused by the proposed works should be mitigated to the maximum practical extent. Following EIAOTM Annex 16 and EIAO Guidance Note No. 3/2002, mitigation measures are discussed in this section to avoid, minimize and compensate for the identified ecological impacts, in the order of priority.

Avoidance

11.136 Potential direct impacts on the marine benthic environment that could have resulted from the laying of the pipeline that will connect all the PTWs to SCISTW, have been avoided by the decision to use subterranean tunneling technique. By this method all pipeline will be laid under the seabed and tunneling will begin from terrestrial based access points. This means that there would be no direct impact on marine benthic communities as a result of pipeline construction.

Minimisation

11.137 To minimize the potential indirect impacts on water quality from construction site runoff and various construction activities, the practices outlined in ProPECC PN 1/94 Construction Site Drainage should be adopted. Detailed mitigation measures to minimise the impacts on water quality associated with all construction activities are discussed in Water Quality Section 6, Para. 6.293-6.324.

11.138 Only 3 colonies of a common hard coral species (Oulastrea crispata) were found at the Aberdeen PTW area to be affected by seawall reconstruction (Figure 11.13). They were all small in size and attached to movable boulders. To avoid/minimize the impact to corals, it is proposed that they are translocated to the eastern end of the existing seawall, which has similar hydrographic parameters and supports healthy growth of the same species and is thus considered as a suitable recipient site (Figure 11.13).. Coral translocation should be carried out during the winter season (November-March) in order to avoid disturbance to the transplanted colonies during the spawning period (i.e. July to October).

11.139 Dredging works will not be carried out and sheet piles or silt curtains will be used to contain filling material used during demolition/re-construction of the seawall. Water quality modelling predicts that no adverse impact on water quality at the proposed recipient (Figure 11.13) site would occur during construction works. Following this, no construction phase monitoring on translocated coral would be required. However, post-translocation monitoring is suggested to be carried out every 3 months for one year. This would be carried out by a marine ecological specialist that is approved by the AFCD. Translocation plan for corals will be submitted to AFCD for approval prior to the commencement of construction works.

11.140 The existing SCISTW outfall location was chosen at an area with low ecological value to avoid adverse impacts on key marine ecological resources. As discussed above, WQO’s for unionized ammonia, salinity, temperature and DO would be met and any changes in these parameters would be highly localised around the SCISTW outfall. There are small exceedances of TIN and Orthophosphate predicted during operation (most likely due to non-HATS sources), but no direct adverse impact on marine ecological communities is expected. Thus, no mitigation measures would be required during operation.

11.141 It is recommended that temporary sewage bypass should be programmed to avoid temporary sewage bypass in wet or bathing season (March to October) in order to minimize the potential impacts. Relevant government departments including EPD and LCSD should be informed of the planned sewage bypass prior to any discharge. During the sewage bypass period, water quality monitoring should be carried out at the water sensitive receivers to quantify the water quality impacts and to determine when the baseline water quality conditions are restored. Also, a framework of the response procedures has been formulated to minimize the impact of temporary discharges. Details are provided in the standalone EM&A Manual.

11.142 Emergency discharges of screened sewage from PTWs would be the consequence of power or equipment failure at SCISTW. Dual power supply would be provided at the SCISTW to minimize the occurrence of power failure. In addition, standby facilities for the main treatment units and standby equipment parts / accessories would also be provided at the SCISTW in order to minimize the chance of emergency discharge. To provide a mechanism to minimise the impact of emergency discharges and facilitate subsequent management of any emergency, an emergency contingency plan has been formulated to clearly state the response procedure in case of total power or equipment failure at SCISTW (details refer to the standalone EM&A Manual). The plant operators of SCISTW should closely communicate with relevant departments including EPD and LCSD during the emergency discharge. An event and action plan and a detailed water quality monitoring programme for the emergency discharge is given in a standalone EM&A Manual.

Compensation

11.143 Seawall area that would be removed during construction activities at Aberdeen PTW would be re-constructed to mitigate direct loss of intertidal habitat.

Evaluation of Residual Impacts

11.144 Based on the above assessment, under normal operation of the project no significant residual impact is anticipated.

11.145 No insurmountable residual impact is expected on marine ecological resources under the emergency discharge scenarios because, emergency discharges would be highly transient in nature, historical records indicate that emergency discharges due to heavy rain and power/equipment failure are rare, mitigation measures to prevent power/equipment failure would be provided and emergency discharge volume is insignificant when compared with the total sewage discharges from the HATS project.

Environmental Monitoring and Auditing

11.146 It is recommended to implement monitoring of the transplanted corals after translocation, every 3 months for one year (this follows previous examples of post-translocation monitoring methodology, proposed in the EM&A Manual for Dredging Work for Proposed Cruise Terminal at Kai Tak).. Information gathered during each post-translocation monitoring survey should include observations on the presence, survival, health condition and growth of the transplanted coral colonies. Oulastrea crispata is not expected to grow significantly over the one year monitoring period but previous study (Lam, 2000) has shown it to have a growth rate of 0.9-1.04 mm per month and thus, growth should be detectable during the post-translocation monitoring period. This would be done by an experienced marine ecological specialist that has been approved by the AFCD. Translocation plan for corals will be submitted to AFCD for approval prior to the commencement of construction works.

11.147 Environmental monitoring and auditing requirements relevant to protection of ecological resources are covered in the Water Quality Assessment, Ecological Risk Assessment in Section 6 and Section 8 respectively and in the standalone EM&A Manual.

Conclusions

11.148 A literature review of previous studies and EIA reports was initially conducted to establish the baseline conditions of the Assessment Area. In areas that were identified to be directly impacted by the project, i.e. Aberdeen PTW, ecological surveys (intertidal and dive surveys) were conducted to gather up to date, detailed information on the baseline condition of the affected site. The assessment of potential impacts was then conducted in accordance with the EIAO TM requirements.

Construction Phase

11.149 Few marine works are necessary during the upgrade of PTWs however, indirect impacts on water quality may result from site run-off, sewage from workforce, accidental spillage and discharges of wastewater associated with land based construction activities. If standard good site practice and the mitigation measures, proposed in Water Quality Section 6, such as the use of silt/sediment and grease traps, effective site drainage and provision of chemical toilets are implemented properly then no significant adverse impact on water quality would be expected.

11.150 Although no marine works are involved during the upgrade of the majority of PTWs, a small area of seawall (approx.50m) would be demolished and reconstructed at the Aberdeen PTW site to complete the construction works. As confirmed by dive surveys, the subject site supported very limited marine life. Only 3 colonies of a common hard coral species (Oulastrea crispata), all in small size (3 to 5cm) and of low coverage were found in the potentially affected areas. All were attached to moveable boulders < 50cm diameter and thus feasible for translocation. Coral translocation and post translocation monitoring is proposed to minimise the adverse impacts on these corals.

Operational Phase

11.151 The water quality impact modeling results in Section 6 indicated that the potential impact zone during operation of the project would be restricted to the Victoria Harbour and Western Buffer WCZs. No significant impacts on ecological resources outside of this zone are expected.

11.152 However, it should be noted that exceedances of Total Inorganic Nitrogen (TIN) and Orthophosphate do occur in Southern and North Western WCZs which are outside the impact areas stated above. These WCZs are not considered to be impacted by the operation of the project because water quality modeling predicts similar levels of these nutrients with and without implementation of the project. Additionally, the ambient nutrient levels of Southern and North Western WCZ already exceed the relevant WQO/WQC suggesting that exceedances of WQO/WQC for these nutrients are likely due to non-HATS sources.

11.153 The existing SCISTW outfall location was chosen specifically to be in an area with low value ecological resources. No significant adverse ecological impacts are anticipated during operation of the Project because:

· Disinfection process will result in improvement of water quality with reduction in E. coli levels in Western Buffer WCZ and western Victoria Harbour WCZ;

· Only localized and small changes in TRC, CBPs and DO around the existing SCISTW outfall;

· No unacceptable ecological risk on marine mammal and marine life in relation to acute and chronic effects;

· Water quality criteria for unionized ammonia is met at the edge of the ZID and this is out of the normal distribution range of dolphins, porpoises and green turtles;

· Unionized ammonia levels would be improved in the North Western, Western Buffer and Victoria Harbour WCZ;

· Oxygen depletion is minimal and highly localized around the SCISTW outfall;

· Improved DO levels in the Victoria Harbour, Eastern Buffer and Junk Bay WCZs;

· Highly localised salinity and temperature changes would not have adverse impacts on the ecological habitats identified;

· Increases in the levels of TIN and Orthophosphate predicted are not significant enough to have direct impacts on identified ecological communities;

· There is no documented data on the specific conditions leading to HABs and they have been documented in polluted and un-polluted water. Increases in nutrient levels during discharge of sewage effluent would be unlikely to trigger HAB events;

· TIN and Orthophosphate levels have increased in the Assessment Area since the implementation of HATS Stage 1, but no increase in the number of HAB events has been observed;

· Water quality modelling predicts little difference in levels of TIN and Orthophosphate with or without the implementation of the project. Additionally, with the implementation of HATS Stage 2B, TIN and phosphate discharge will be reduced;

· Western Buffer WCZ and western Victoria Harbour WCZ, the areas affected by the effluent, generally support low to moderate ecological resources;

11.154 Emergency discharge of sewage effluent at PTW and SCISTW may occur during periods of heavy rain when inflow exceeds the capacity of the system or as a result of power/equipment failure. This would result in a rise in the level of E. coli in the receiving water body and thus a subsequent deterioration in water quality which would potentially cause adverse impacts to marine ecological resources. Water quality modelling showed that pollution levels for parameters such as nutrients and DO were not predicted to be adversely affected by emergency discharges. Additionally modelling predicted that increases in the level of suspended sediment resulting from emergency discharges would not exceed the assessment criteria at coral sites. Water quality was also predicted to return to normal condition 1 to 2 days after emergency discharges. Due to the highly transient nature of potential emergency discharges and the ability of marine organisms to naturally resist pathogenic strains of E. coli (Hang et al., 2000) no insurmountable impact on water quality is predicted to result from emergency discharges.

11.155 Environmental monitoring and auditing requirements relevant to ecological resources protection are described in detail in the standalone EM&A Manual.

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