4 Baseline Conditions & Sensitive Receivers

4.1 Introduction

This Section of the report describes the environmental baseline conditions in the Study Area focussing on the key elements of the Project. The information is taken from a variety of sources including published literature, consultancy reports, recent field survey information and grey literature. References are presented in each of the following sections for data sources. Where previously approved EIA Reports have been referred to, the guidelines in the EIAO-TM have been followed.

4.2 Water Quality

4.2.1 Introduction

This Section describes baseline hydrodynamics, water and sediment quality within the Study Area for the proposed CMPs at South Brothers/East of Sha Chau.

4.2.2 Hydrodynamics

The hydrodynamic regime in the vicinity of the proposed CMPs at South Brothers and East of Sha Chau is complex and varies with a number of factors including the lunar cycle (spring and neap cycle), the season and the rate of flow of the Pearl River. In general, the main ebb tide currents flow south along the Urmston Road, with a subsidiary flow bifurcating northwest of Chek Lap Kok to flow south down the west coast of Lantau, and southeast around the east of Chek Lap Kok Island. Flood tides show the reverse pattern.

During the dry season the influence of the Pearl River is at its least because of reduced flows, resulting in typically well-mixed coastal waters. In contrast during the summer (wet) season, the flow of the Pearl River increases and the coastal waters become highly stratified as the large influx of brackish water overlies the denser, more saline oceanic waters near the sea bed.

Currents in the area are generally strongest on dry season spring tides. The strength of the currents has been measured in two studies. The first found moderate to low velocities (generally less than 0.4 m s^-1) predominated by velocities rising to 1.0 - 1.5 m s ^-1 during spring tides ([1]). The second study, which looked only at spring tides, recorded a maximum of 0.6 m s^-1 ([2]). Acoustic Doppler Current Profiler surveys were undertaken in the vicinity of the CMP IV pits as part of the EIA Study on the spring tide of 19-20 January 1996 (dry season) and the spring and neap tides of July-August 1996 (wet season). These data were used in calibration and validation of the TELEMAC model which was used in the previous CMP IV EIA. The study found current velocities of up to 1.1 m s^-1 on spring tides and up to 0.7 m s^-1 on neap tides.

Within the Study Area lies the Airport Sea Channel. The airport platform was designed such that the channel between it and the northern coast of Lantau Island would be retained. The main purpose of this channel was to achieve adequate flows in the East Tung Chung Bay, which would not have been possible had the airport been connected to the Lantau coastline. The design of the sea channel was such that it should be at a minimum self-flushing (complete exchange of water in the channel at least once per day). A series of water quality monitoring surveys have been conducted around the airport platform, in the Airport Sea Channel and East Tung Chung Bay. Early field investigations (ADCP measurements) and computer modelling studies revealed that flows within the Airport Sea Channel were exceeding specifications and so the design purpose of the channel was confirmed. The predicted flows within the sea channel have also since been confirmed.

Further to the east of the Airport is Tai Ho Bay, which is located and enclosed by the North Lantau Expressway. The bay is connected to the sea via one main box culvert through which small vessels can pass and this is the main area for tidal exchange. There are two other smaller culverts along the reclamation seawall. The current velocities within Tai Ho Bay have been demonstrated in recent field investigations to be extremely low (0.08 ms^-1 median velocity at the landward side of the box culvert at the mouth of the bay decreasing to 0.02 ms^-1 within 300m of the box culvert ^([3])).

South Brothers

The current velocities are generally very low in the area around the proposed pits (Part 2, Section 2.2). Current velocities are highest in the surface layer and range from < 0.25 m s^-1 during slack tides to < 0.75 m s^-1 during peak flood and peak ebb. Velocities in the bed layer do not exceed 0.25 m s^-1. An examination of the plots for each of the three pits (see Part 2, Section 2) indicates that in general Pit A can be considered as the most dispersive as the current velocities are highest of the differing states of the tide and seasons. Pit C is the least dispersive as current velocities rarely exceed 0.25 m s^-1.

East of Sha Chau

The pits are located closer to the main flow path of the Urmston Road and consequently, in comparison to the current velocities at South Brothers those at East of Sha Chau are generally much higher (see Part 3, Section 3). Current velocities can reach 2.0 m s^-1. Ebb tide currents are towards the southeast where the flood tide currents move to the northwest. In a similar fashion to the South Brothers site the bed layer currents are of low velocity rarely exceeding 0.25 m s^-1.

4.2.3 Water Quality

Changes in the hydrodynamic regime that result from changes in the flow of the Pearl River have a major influence on the water quality in the vicinity of the CMPs at South Brothers and East of Sha Chau. During the summer (wet) season (mid-April to mid-October) there is a large influx of freshwater from the Pearl River which results in steep salinity gradients. The river water typically carries high silt and organic pollutant loads which impact the ambient water quality. In contrast, during the winter (dry) season (mid-October to mid-April), freshwater input is much lower, and conditions are more typically oceanic, as saline water moves northwards into the Pearl River Delta and the water bodies become well-mixed. Data from the Environmental Protection Department (EPD) collected under the Routine Water Quality Monitoring Programme have been utilised to define the background water quality parameters in the Study Area (Table 4.1Table 4.1Table 4.1). In addition to the annual average, both wet and dry season means have been calculated.

The data from EPD, which were collected between 1998 and 2002, appear to indicate that there have been elevations in Suspended Solids (SS), Total Inorganic Nitrogen (TIN) and Ammonia Nitrogen over time. There has also been a sharp increase in E. coli, which has been attributed to an increase in sewage discharges through the Northwest New Territories Outfall ^([4]). In terms of compliance with WQOs, no exceedances have been recorded with the exception of TIN, which regularly exceeds the WQO. The average annual 90^th percentile suspended solids concentration (ambient) for the period 1998 – 2002 was 17.4 mg L^-1. In the dry season the ambient was 19 mg L^-1 and in the wet season the ambient was 15.5 mg L^-1. These values would give an allowable increase in suspended sediment concentrations according to the WQO of 5.2 mg L^-1 annually (or 5.7 mg L^-1and 4.7 mg L^-1for dry and wet season respectively).

Information on metal concentrations in the water column in the vicinity of the CMPs at South Brothers and East of Sha Chau is presented in Table 4.2Table 4.2Table 4.2. These data were collected between November 1997 and December 2000 during the CMP IVa and IVb EM&A programme. It should be noted that the objective of the monitoring was to identify whether there were differences between concentrations of contaminants in waters samples collected in areas down-current from the CMP during backfilling operations in comparison to those up-stream. As such, the data collected at the up-stream stations can be considered to be reflective of ambient conditions.

Table 4.1 EPD Routine Water Quality Monitoring Data Collected between 1998 and 2002

Parameter	EPD Water Quality Monitoring Station
		NM2			NM3			NM5			NM6
	Annual	Wet Season	Dry Season	Annual	Wet Season	Dry Season	Annual	Wet Season	Dry Season	Annual	Wet Season	Dry Season
Temperature (°C)	23.7 (16.8- 29.7)	26.3 (21.8- 29.7)	21.1 (16.8- 28.1)	23.5 (16.8- 28.9)	26.0 (21.8- 28.9)	21.0 (16.8- 28.2)	23.7 (16.8- 30.1)	26.3 (21.9- 30.1)	21.6 (16.8- 28.4)	23.8 (16.3- 29.6)	26.9 (21.8- 29.6)	20.8 (16.3- 27.9)
Salinity (ppm)	28.2 (9.4 - 33.3)	26.6 (9.4- 32.6)	31.3 (25.7- 33.3)	28.8 (11.1- 33.2)	26.5 (11.1- 32.2)	31.1 (19.6- 33.2)	27.4 (4.9- 33.2)	24.6 (4.9- 32.1)	29.6 (7.9- 33.2)	26.1 (7.6- 33.7)	21.4 (7.6- 31.2)	30.7 (26.2- 33.7)
Dissolved Oxygen (mg L^-1) (Depth Average)	6.0 (3.2- 9.2)	5.6 (3.2- 8.9)	6.5 (3.4- 9.2)	5.9 (2.2- 8.8)	5.2 (2.2- 8.6)	6.6 (3.7- 8.8)	5.9 (2.3- 9.2)	5.1 (2.3- 9.2)	6.4 (3.2- 9.0)	6.5 (3.9- 11.8)	6.1 (3.9- 11.8)	6.8 (4.1- 9.5)
Dissolved Oxygen (mg L^-1) (Bottom)	5.9 (3.2- 8.4)	5.1 (3.2- 7.6)	6.6 (4.3– 8.4)	5.6 (2.2- 8.6)	4.6 (2.2- 7.0)	6.7 (4.4- 8.6)	5.5 (2.3- 8.8)	4.4 (2.3- 6.3)	6.4 (3.2- 8.8)	6.4 (3.9- 11.8)	6.0 (3.9- 11.8)	6.9 (4..5- 9.2)
Dissolved Oxygen (% Saturation) (Depth Average)	83.4 (46.0- 132.0)	74.3 (52.0- 93.0)	87.0 (52.0- 120.0)	81.2 (32.0- 128.0)	74.1 (32.0- 128.0)	88.2 (55.0- 109.0)	80.6 (33.0- 130.0)	73.3 (33.0- 130.0)	86.4 (45.0- 114.0)	89.0 (56.0- 170.0)	86.9 (56.0- 170.0)	91.0 (59.0- 120.0)
Dissolved Oxygen (% Saturation) (Bottom)	81.1 (46.0- 114.0)	73.6 (46.0- 114.0)	88.3 (66.0- 109.0)	77.9 (32.0- 108.0)	66.7 (32.0- 98.0)	89.1 (66.0-108.0)	75.9 (33.0- 110.0)	63.5 (33.0- 94.0)	85.9 (45.0- 110.0)	88.8 (56.0- 167.0)	85.0 (56.0- 167.0)	92.6 (61.0- 116.0)
Suspended Solids (mg L^-1)	8.2 (1.1- 47.0)	6.4 (1.7- 32.0)	10.0 (1.1- 47.0)	10.5 (1.2- 71.0)	9.6 (1.8- 46.0)	11.5 (1.2- 71.0)	12.7 (1.6- 210.0)	15.0 (2.0- 210.0)	10.8 (1.6- 73.0)	9.6 (1.2- 60.0)	7.4 (1.2- 25.0)	11.8 (2.1- 60.0)
5-day Biochemical Oxygen Demand (mg L^-1)	0.7 (0.1- 3.5)	0.8 (0.1- 3.5)	0.5 (0.1- 1.5)	0.7 (0.1- 2.2)	0.8 (0.1- 1)	0.6 (0.1- 1.7)	0.8 (0.1- 4.1)	0.8 (0.1- 2.9)	0.8 (0.1- 4.1)	0.9 (0.1- 4.9)	1.0 (0.1- 3.5)	0.8 (0.1- 4.9)
Unionised Ammonia (mg L^-1)	0.005 (0.001- 0.02)	0.01 (0.001- 0.02)	0.04 (0.002- 0.01)	0.005 (0.001- 0.03)	0.005 (0.001- 0.03)	0.004 (0.001- 0.01)	0.006 (0.001- 0.03)	0.006 (0.001- 0.02)	0.006 (0.002- 0.03)	0.005 (0.001- 0.02)	0.006 (0.001- 0.02)	0.003 (0.001- 0.01)
Total Inorganic Nitrogen (mg L^-1)	0.4 (0.1- 1.4)	0.5 (0.2- 1.4)	0.3 (0.1- 1.0)	0.4 (0.2- 1.3)	0.5 (0.2- 1.3)	0.3 (0.2- 0.6)	0.5 (0.1- 1.6)	0.7 (0.2- 1.6)	0.4 (0.1- 1.4)	0.5 (0.05- 1.6)	0.7 (0.1- 1.6)	0.3 (0.05- 0.6)
Chlorophyll-a (mg/L)	3.0 (0.0- 23.0)	3.3 (0.5- 18)	2.7 (0.0- 23.0)	2.7 (0.2- 25.0)	2.4 (0.3- 1.2)	2.9 (0.2- 25.0)	3.0 (0.2- 28.0)	3.0 (0.2- 23.0)	2.9 (0.3- 28.0)	3.8 (0.4- 44.0)	4.5 (0.4- 44.0)	3.0 (0.4- 27.0)
E. coli (cfu 100 ml^-1)	681 (5- 6,000)	739 (5- 6,000)	625 (24- 3,300)	2893 (46-180,000)	4,557 (46-180,000)	1,250 (56- 34,000)	1189 (13- 28,000)	1356 (13- 28,000)	1,055 (48- 6,400)	66 (1- 720)	77 (1- 720)	56 (0.4- 350)
Notes: 1. Data presented are depth averaged, except as specified. 2. Data presented are annual arithmetic mean except for E. coli, which are geometric means and dissolved oxygen, which are 10th percentile. 3. Data enclosed in brackets indicate the ranges. 4. Shaded cells indicate non-compliance with the WQOs

Table 4.2 Dissolved Metal Data Recorded between 1997 and 2000 at East of Sha Chau

Parameter	DL^a	All Stations			Upstream (Control) Stations
		Ave	Min	Max	Ave	Min	Max
Cadmium (mg L^-1)	0.2	0.1	0.1	0.4	0.1	0.1	0.2
Chromium (mg L^-1)	1.0	0.5	0.5	11.0	0.8	0.5	11.0
Copper (mg L^-1)	1.0	0.9	0.5	11.0	0.9	0.5	3.0
Lead (mg L^-1)	1.0	0.5	0.5	4.0	0.5	0.5	0.5
Mercury (mg L^-1)	0.1	0.1	0.1	0.3	0.1	0.1	0.3
Nickel (mg L^-1)	1.0	1.4	0.5	5.0	1.7	0.5	4.0
Silver (mg L^-1)	1.0	0.5	0.5	0.5	0.5	0.5	0.5
Zinc (mg L^-1)	10.0	6.2	5.0	90.0	6.3	5.0	20.0
Arsenic (mg L^-1)	2.0	1.8	1.0	10.0	1.4	1.0	8.0
Note: a. DL = Detection Limit

4.2.4 Sediment Quality

EPD collects sediment quality data as part of the marine sediment quality monitoring programme. There are three monitoring stations in the vicinity of the CMPs at South Brothers and East of Sha Chau. Data for these stations have been published in the latest marine water quality monitoring report and are presented in Table 4.3. The published data represent the range of values obtained in the period 1996 to 2002.

Recent data on sediment quality in the vicinity of the proposed CMPs at South Brothers and East of Sha Chau have also been collected under the CMP IVa and IVb EM&A programme ([5]). Under this monitoring programme a number of sediment stations were monitored, however, for the purposes of providing background information on the sediment quality in the vicinity of the proposed CMPs, one set of regional sampling stations is considered to be most representative of background conditions. These stations are located within the RMB site and are presented on Figure 4.2a. Data from these stations collected between November 1997 and December 2000 presented in Table 4.4Table 4.4Table 4.4. According to the data collected at these stations no exceedances of either the Lower Chemical Exceedance Level (LCEL) or Upper Chemical Exceedance Level (UCEL), as set by the ETWBTCW 34/2002, were recorded.

TTable 4.3 EPD Routine Sediment Quality Monitoring Data collected between 1996 and 2002

Parameter	LCEL^1	UCEL^2	EPD Sediment Quality Monitoring Station
				NS2			NS3			NS6
			Average	Min	Max	Average	Min	Max	Average	Min	Max
Particle Size Fraction (<63mm) (% w/w)	-	-	74	46	94	57.5	5	87	57.2	26	92
Total Solids (% w/w)	-	-	51.7	46	58	55.3	47	69	60.6	47	71
Total Volatile Solids (%TS)	-	-	6.28	5	7.2	6.17	3.1	7.5	5.07	3	8.3
Dry Wet Ratio -	-	-	0.496	0.46	0.54	0.552	0.44	0.69	0.592	0.47	0.72
Chemical Oxygen Demand (mg kg^-1)	-	-	13,600	10,000	16,000	15,140	8,400	18,000	12,370	7,400	17,000
Total Carbon	-	-	0.55	0.5	0.7	0.58	0.4	0.7	0.48	0.4	0.7
Ammonia Nitrogen (mg kg^-1)	-	-	3.65	1	7.2	5.52	0.5	12	3.755	0.51	16
TKN (mg kg^-1)	-	-	306	270	360	305	250	360	240	160	370
Total Phosphorus (mg kg^-1)	-	-	183	170	200	186	150	240	139.3	73	230
Total Sulphide (mg kg^-1)	-	-	17.33	1	47	25.8	4.7	94	4.7625	0.6	15
Total Cyanide (mg kg^-1)	-	-	0.1	0.1	0.1	0.2	0.1	0.5	0.1	0.1	0.1
Aluminium (mg kg^-1)	-	-	27,500	21,000	35,000	25,400	13,000	36,000	22,460	9,600	48, 000
Arsenic (mg kg^-1) *	12	42	11.3	9.2	14	11. 8	6.3	14	11.6	8	22
Barium (mg kg^-1)	-	-	33.7	25	41	31.3	17	44	27.5	16	48
Boron (mg kg^-1)	-	-	23	20	29	20.6	11	28	18.1	11	31
Cadmium (mg kg^-1)	1.5	4	0.1	0.1	0.1	0.14	0.1	0.3	0.15	0.1	0.2
Chromium (mg kg^-1)	80	160	33.5	30	43	32.1	16	41	25.8	15	45
Copper (mg kg^-1)	65	110	35	27	50	34.3	17	47	16.3	7	34
Iron (mg kg^-1)	-	-	29300	26000	36000	28300	15000	35000	26200	14000	45000
Lead (mg kg^-1)	75	110	39.4	32	55	38.9	20	54	29.8	17	49
Manganese (mg kg^-1)	-	-	448	400	510	447	230	620	374	200	700
Mercury (mg kg^-1)	0.5	1	0.09	0.06	0.16	0.12	0.06	0.19	0.1	0.05	0.15
Nickel (mg kg^-1)	40	40	18.7	16	24	18.7	10	25	16	9	27
Silver (mg kg^-1)	1	2	1	1	1	1	1	1	1	1	1
Vanadium (mg kg^-1)	-	-	34.3	28	41	37.9	17	54	33	19	65
Zinc (mg kg^-1)	200	270	96.9	73	120	90	48	120	68.6	34	120
Total PCBs (mg kg^-1)	23	180	8.67	5	15	12.3	8	15	9	9	9
Notes: 1. LCEL = Lower Chemical Exceedance Level 2. UCEL = Upper Chemical Exceedance Level 3. Grey shaded cells indicate exceedance of LCEL 4. * Arsenic data are only available for 1996-2000

Table 4.4 Sediment Quality Data Collected between 1997 and 2000 at East of Sha Chau

Parameter	DL^1	LCEL^2	UCEL^3	Average	StDev	Min	Max
Metals (mg kg^-1)
Cadmium	0.02	1.5	4	0.07	0.02	0.05	0.10
Chromium	0.05	80	160	20	6	12	30
Copper	0.05	65	110	15	4	11	23
Mercury	0.05	0.5	1	0.07	0.02	0.05	0.10
Nickel	0.05	40	40	12	4	7	19
Lead	0.05	75	110	27	7	22	38
Silver	0.05	1	2	0.12	0.04	0.09	0.20
Zinc	5	200	270	51	15	33	76
Metalloid (mg kg^-1)
Arsenic	0.5	12	42	8	2	6	12
Organic - PAHs (mg kg^-1)
Low M Wt PAHs	50	550	3160	75	0	75	75
High M Wt PAHs	150	1700	9600	26	2	25	32
Organics - non - PAHs (mg kg^-1)
Total PCBs	2	23	180	1.2	0.2	1.0	1.6
Notes: 1. DL = Detection Limit 2. LCEL = Lower Chemical Exceedance Level 3. UCEL = Upper Chemical Exceedance Level

Ground Investigation Works

In addition to the background data presented above, a ground investigation and marine sediment sampling survey was conducted within both the South Brothers and East of Sha Chau areas as part of the Site and Disposal Option Selection phase of the study. Although the primary objective of this survey was to investigate the thickness of mud, sediment samples were also analysed to determine the potential for contamination.

Locations of the vibrocores are presented in Figure 4.2a. The results from vibrocore V12 are considered to be applicable to the South Brothers area, this sample exhibited no exceedances of the LCEL. Vibrocore V1 provided information on the sediment quality in the East of Sha Chau area, which also exhibited no exceedances of the LCEL. It can be concluded from the ground investigation works that the sediments in the two locations appear to be predominantly uncontaminated.

4.2.5 Water Quality Sensitive Receivers

The sensitive receivers that may be affected by changes in water quality during the construction or operation of the facility are listed in the Study Brief, discussed below and presented on Figure 4.2b. For each of the sensitive receivers, established threshold criteria or guidelines have been identified and the method of reviewing these sensitive receivers (either through discrete points or contour plots) during the water quality modelling has been described. The shortest distances from the water quality sensitive receivers to the CMPs at South Brothers and East of Sha Chau is presented in Table 4.5.

Table 4.5 Water Quality Sensitive Receivers (SR)

SR	Name	Shortest Distance to CMPs (m)
		South Brothers	East of Sha Chau
Marine Parks	Sha Chau and Lung Kwu Chau SE (MP1)	7,289	2,005
	Sha Chau and Lung Kwu Chau E (MP2)	9,291	3,594
	Sha Chau and Lung Kwu Chau NE (MP3)	11,595	6,090
	Sha Chau and Lung Kwu Chau SW (MP4)	9,570	4,926
Fish Culture Zone	Ma Wan N (FCZ1)	8,114	10,885
	Ma Wan S (FCZ2)	7,932	10,949
Artificial Reefs	Airport AR (AR1)	2,397	1,041
	Sha Chau and Lung Kwu Chau AR (AR2)	9,778	4,232
Beaches	Lung Kwu Tan Lower (B1)	9,162	4,795
	Lung Kwu Tan Upper (B2)	10,951	6,662
	Butterfly Beach (B3)	5,596	2,730
	Tuen Mun Beaches (B4)	5,681	4,653
Intakes	Airport (I1)	3,047	1,700
	Airport (I2)	2,113	2,186
	Airport (I3)	4,109	4,967
	Airport (I4)	5,185	4,583
	Tuen Mun (I5)	5,246	3,435
	Castle Peak Power Station (I6)	8,737	3,950
	Area 38 Industries (I7)	6,746	2,150
Seagrass & Horseshoe Crabs	San Tau (SG1)	4,645	5,491
	Tai Ho Bay (SG2)	1,016	5,079
	Yam O Bay (SG3)	4,129	7,942
	Horseshoe Crab Tung Chung Bay (HC1)	4,449	5,890
EPD WQM Stations	NM1 – close to Yam O	5,418	8,100
	NM2 – close to Castle Peak Bay	4,858	3,822
	NM3 – close to River Trade Terminal	5,031	566
	NM5 - Urmston Road	9,854	4,477
	NM6 – between Marine Park and Airport	7,107	2,666

Fish Culture Zone

There is only one fish culture zone (FCZ) located within the northwestern waters of Hong Kong, which is at Ma Wan. This FCZ is actually outside of the water quality assessment area but is included for completeness. The only Water Quality Objective (WQO) that is specific to FCZs is for dissolved oxygen, which is set at no less than 5 mg L^-1. In addition to dissolved oxygen there is a general water quality protection guideline for suspended solids (SS), which has been proposed by AFCD ^([6]). The guideline requires that SS levels remain below 50 mg L^-1. With regard to the water quality modelling, the FCZs were included as discrete points for evaluation in the assessment against the above criteria and guideline.

Marine Ecological Resources

The following Marine Ecological Resources have been identified as water quality sensitive receivers.

Marine Parks

There is one designated Marine Park located within the Study Area which is the Sha Chau and Lung Kwu Chau Marine Park (see Section 4.3). The park was designated specifically for the protection of the Indo-Pacific Humpback Dolphin (Sousa chinensis). There are no specific legislative water quality criteria for Marine Parks rather; the water quality at this sensitive receiver is typically compared with the WQO. The Marine Park will be plotted as a discrete point at the marine water boundary facing the proposed mud pits for evaluation in the water quality assessment.

Artificial Reef Deployment Sites

There are two gazetted Artificial Reef Deployment Sites (ARD) within the Study Area:

· Sha Chau and Lung Kwu Chau ARD site (situated within the Sha Chau and Lung Kwu Chau Marine Park);

· Airport ARD site (Figure 4.2b).

The ARD sites are proposed as a fisheries resource enhancement tool to encourage growth and development of a variety of marine organisms and provide feeding opportunities for the Indo-Pacific Humpback Dolphin. There is no specific water quality criterion for the ARD sites; rather water quality impacts are measured presently against compliance with the WQO. The ARD sites will be treated as discrete points in the model.

Seagrass Beds, Mangroves & Horseshoe Crabs

There are seagrass beds, mangroves and areas where horseshoe crabs are known to breed within the Study Area, such as within Tung Chung Bay, Tai Ho and Yam O Bays (see Section 4.3). There are no specific legislative water quality criteria for these seagrass beds/breeding areas, rather, the water quality at these sensitive receivers is typically compared with the WQO. The sensitive habitats will be plotted as discrete points for evaluation in the water quality assessment.

Non-Gazetted & Gazetted Bathing Beaches

There are several non-gazetted and gazetted bathing beaches within the Study Area, which have been identified in the Study Brief as sensitive receivers. These include the beaches at Lung Kwu Tan and around Tuen Mun. Water quality impacts are determined based on the compliance with the WQO. Bathing beaches have been plotted as discrete points for evaluation in the water quality assessment.

Seawater Intakes

There are several water intakes in the Study Area which are mainly for cooling purpose. In absence of specific criteria for each intake we have assumed the WQO as a default. The exception to the above is for the Castle Peak Power Station intake for which there is a specific requirement that suspended sediment concentrations be maintained below a level of 150 mg L^-1 within a 5 km radius of the intake. The intakes will be plotted as discrete points for evaluation in the water quality assessment.

Summary

A summary of the assessment criteria to be applied for each sensitive receiver for this Project is presented in Table 4.6

Table 4.6 Summary of Assessment Criteria for Water Quality Sensitive Receivers

Sensitive Receiver	Specific Assessment Criteria	Value
Fish Culture Zone (FCZ)	Dissolved oxygen Suspended Solids	No less than 5 mg L^-1 No more than 50 mg L^-1
Marine Park, Artificial Reefs, Seagrass, Horseshoe Crabs, Non-gazetted & Gazetted Bathing Beaches	Water Quality Objectives
Seawater Intakes	Water Quality Objectives	Water Quality Objectives

4.3 Marine Ecology

4.3.1 Introduction

This section of the report presents baseline information on the marine ecological resources within the Study Area, summarises their ecological value and identifies sensitive receivers, examples of which can be see in Figure 4.2c.

The marine ecology of north Lantau is well documented. The distribution of the marine ecological important habitats, including seagrass, mangrove, mudflat, dolphin and benthic soft bottom habitats, have been comprehensively studied, sources are listed below:

· Barros NB, Jefferson TA and ECM Parsons (2004) Feeding habits of Indo-Pacific humpback dolphins (Sousa chinensis) stranded in Hong Kong. Aquatic Mammals. 30:179-188

· Binnie Consultants Limited (1996) Fill Management Study - Phase IV Investigations and Development of Marine Borrow Areas: Coral Growth at High Island Dam. For the Civil Engineering Department, Hong Kong SAR Government.

· Binnie Consultants Limited (1997) Chek Lap Kok Qualitative Survey. Final Report. For the Civil Engineering Department, Hong Kong SAR Government.

· Chiu HMC and Morton B (1999) The distribution of horseshoe crabs (Tachypleus tridentatus and Carcinoscorpius rotundicauda) in Hong Kong. Asian Marine Biology. 16, 185-196.

· CityU Professional Services Limited (2002) Agreement No. CE 69/2000 - Consultancy Study on Marine Benthic Communities in Hong Kong. Final Report. Submitted to the Agriculture, Fisheries and Conservation Department. Hong Kong SAR Government.

· ERM – Hong Kong, Ltd (1995) Proposed Aviation Fuel Receiving Facility at Sha Chau. Environmental Impact Assessment. Prepared for the Provisional Airport Authority.

· ERM - Hong Kong, Ltd (2000) Northshore Lantau Development Feasibility Study. Environmental Impact Assessment. Final Report. For the Civil Engineering Department, Hong Kong SAR Government.

· ERM - Hong Kong, Ltd (2002) Agreement No CE 44/97 - Environmental Monitoring and Audit for Contaminated Mud Pit IV at East of Sha Chau. Final Report. For the Civil Engineering Department, Hong Kong SAR Government.

· ERM-Hong Kong, Ltd (2000) Construction of an International Theme Park in Penny’s Bay of North Lantau together with its Essential Associated Infrastructures – EIA Report. For the Civil Engineering Department, Hong Kong SAR Government

· Fong TCW (1998) Distribution of Hong Kong seagrasses. Porcupine! 18, December 1998.

· Fong TCW (1999) Tai Ho Bay: breeding and nursery ground of horseshoe crabs. Porcupine! No. 20, November 1999.

· Jefferson TA (2000) Population biology of the Indo-Pacific Humpback dolphin in Hong Kong waters. Wildlife Monographs 144:1-65.

· Jefferson TA (2002) Monitoring of Indo-Pacific Humpback Dolphins (Sousa chinensis) in Hong Kong waters. Final Report. For the Agriculture, Fisheries and Conservation Department, Hong Kong SAR Government.

· Jefferson TA and SK Hung (2004) A review of the status of the Indo-Pacific humpback dolphin (Sousa chinensis) in Chinese waters. Aquatic Mammals. 30:149-158

· Jefferson TA, Hung SK, Law I, Torey M and Tregenza N (2002) Distribution and abundance of finless porpoises in Hong Kong and adjacent waters of China. Raffles Bulletin of Zoology Supplement 10:43-55.

· Lee SY (1997) Annual cycle of biomass of a threatened population of the intertidal seagrass Zostera japonica. Marine Biology 129: 183 - 193.

· Lun JCY (2003) Hong Kong. Reef Building Corals. Cosmos Books Limited.

· Mott Connell Ltd (2003) Environmental Impact Assessment for Tung Chung - Ngong Ping Cable Car Project. Final Report. For the MTR Corporation.

· Mouchel Asia Limited (2002) Agreement No CEO 01/2001 - Environmental Assessment Study for Backfilling of Marine Borrow Pits at North of the Brothers. Environmental Assessment Report. For the Civil Engineering Department, Hong Kong SAR Government.

· Mouchel Asia Ltd (2002) Permanent Aviation Fuel Receiving Facility for Hong Kong International Airport. Environmental Impact Assessment Report. For the Airport Authority Hong Kong.

· Scott PJB (1984) The Corals of Hong Kong. Hong Kong University Press.

· Tam NFY and Wong YS (1997) Ecological Study on Mangrove Stands in Hong Kong: Volume 1. University Press, Hong Kong.

· ERM – Hong Kong Ltd (2000) Environmental Impact Assessment, Construction of an International Theme Park in Penny’s Bay of North Lantau and its Essential Associated Infrastructures. Final EIA Report Annex (Volume 1)

· ERM (1998) Seabed Ecology Studies: Composite Report for CED

· ERM (2003) Study in Terrestrial Habitat Mapping and Ranking Based on Conservation Value. Report for SDU.

· ERM (2000) SUSDEV 21 Environmental Baseline Survey on Terrestrial Habitat Mapping and Ranking based on Conservation Value, Report for PlanD.

Taking into consideration the available literature, marine ecological baseline surveys were not considered necessary. The existing conditions of each of the ecological sensitive areas at north Lantau are presented in the following sections.

4.3.2 Existing Conditions and Ecological Value

The Study Area has been defined in the EIA Study Brief and is the same as that for the Water Quality Impact Assessment presented in Figure 4.2b. The waters lie wholly in the North Western Water Control Zone (WCZ), the baseline conditions of which have been described in Section 4.2. As unacceptable perturbations to water quality are unlikely to extend outside of the Study Area, the characterisation of existing conditions will focus on the marine ecological resources inside this area.

Based on current understanding of the Study Area, the following habitats and/or organisms of ecological interest have been identified within the Study Area:

· Soft Bottom Habitats;

- Subtidal Soft Bottom Habitats

· Infauna

· Epibenthic Fauna

- Intertidal Soft Bottom Habitats

· Mangroves

· Mudflats (including Horseshoe Crabs)

· Seagrass

· Hard Bottom Habitats;

- Subtidal Hard Bottom Habitats

- Intertidal Hard Bottom Habitats

· Marine Mammals;

· Sites of Special Scientific Interest (SSSI)

· Marine Parks

Key locations of each of the above habitats are presented in Figure 4.3a.

The existing conditions of each of the above habitats/organisms based on currently available literature, are presented in the following sections. Based on these conditions, the ecological value for each habitat has been determined according to the EIAO-TM Annex 8 criteria, as follows:

· Naturalness

· Size

· Diversity

· Rarity

· Re-creatability

· Fragmentation

· Ecological Linkage

· Potential Value

· Nursery Ground

· Age

· Abundance

Soft Bottom Habitats

Subtidal Soft Bottom Habitats

Infauna

Soft sediments consisting of mud, clay and sand dominate the seabed of Hong Kong. These soft bottom habitats support both infauna and epibenthic faunal marine communities, which in turn play a vital role as a food source for the majority of Hong Kong’s inshore fisheries resources. A number of studies provide information on infaunal assemblages with the Study Area. The most recent of these studies examined infaunal benthic assemblages throughout Hong Kong and, using multivariate statistics, identified 5 major groupings of infauna ([7]). The data from the studies allow a comparison to be made of the diversity and abundance of infaunal benthic assemblages within the Study Area (represented by Stations 11 – 21, with those throughout Hong Kong waters ([8]) (see Figure 4.3a).

From the summer survey results, it appears that all the stations within the Study Area, with the exception of Stations 11 and 12 in the vicinity of Lung Kwu Chau, lie within the same group as those in Western Harbour, South Lantau waters, Southern and Eastern Waters, thus the majority of stations in Hong Kong (48.5% of stations surveyed). Dominant fauna within this group were polychaetes. No species considered to be of high ecological value were identified. The two stations within the vicinity of Lung Kwu Chau were considered to be more similar to stations in Deep Bay due to the presence of more freshwater associated species present at these sites during the summer months. In contrast, during the winter months, all stations within the Study Area were found to be similar to other stations in Hong Kong (49.5% of stations surveyed). Dominant fauna within this group were again found to be polychaetes. No species considered to be of high ecological value were identified in the winter survey.

Based on the findings of the Hong Kong wide survey, the benthic infaunal assemblages within the Study Area can be expected to be typical of Hong Kong soft bottom habitats. Two stations, located within close proximity to Lung Kwu Chau, were identified as demonstrating seasonal changes, which are likely to be as a result of the more estuarine conditions experienced at these sites  ([9]) . The assemblages were all dominated by polychaetes and all species recorded occur frequently in Hong Kong with no rare species observed. Following the EIAO-TM criteria, the ecological importance of the benthic infaunal assemblages both within and within close proximity to, the proposed CMPs at South Brothers and East of Sha Chau has been assessed in Table 4.7.

Table 4.7 Ecological Value of Benthic Infaunal Assemblages at the proposed CMPs at South Brothers and East of Sha Chau

EIAO-TM Criteria	South Brothers	East of Sha Chau
Naturalness	The assemblages are expected to be moderately disturbed due to fishing operations and high marine traffic within these waters	The assemblages are expected to be moderately disturbed due to fishing operations and high marine traffic within these waters
Size	Total area of the temporarily affected subtidal habitats will involve approximately 164 hectares	Total area of the temporarily affected subtidal habitats will involve approximately 115 hectares
Diversity	The assemblages are of similar diversity to the majority of other areas in Hong Kong	The assemblages are of similar diversity to the majority of other areas in Hong Kong
Rarity	No organisms were found that are considered as rare	No organisms were found that are considered as rare
Re-creatibility	The habitat can be expected to recreate naturally within a relatively short timeframe through sediment deposition	The habitat can be expected to recreate naturally within a relatively short timeframe through sediment deposition
Fragmentation	The surrounding environment contains many other areas of soft substrate	The surrounding environment contains many other areas of soft substrate
Ecological Linkage	The benthic infauna act as a food source for epibenthic organisms	The benthic infauna act as a food source for epibenthic organisms
Potential Value	Unlikely that the site can develop conservation interest	Unlikely that the site can develop conservation interest
Nursery Ground	None identified	None identified
Age	The sediments in the habitat are constantly accreting and eroding and the fauna present there are typically short lived	The sediments in the habitat are constantly accreting and eroding and the fauna present there are typically short lived
Abundance	Abundance of infauna are comparable to the majority of other areas in Hong Kong	Abundance of infauna are comparable to the majority of other areas in Hong Kong
Summary	The subtidal soft bottom habitat within the proposed CMP at South Brothers is likely to support species that are typical of Hong Kong with no rare species present.	The subtidal soft bottom habitat within the proposed CMP at East of Sha Chau is likely to support species that are typical of Hong Kong with no rare species present.
Ecological Value	Low	Low

Epibenthic Fauna

Subtidal soft bottom habitats, as well as supporting infaunal species, commonly support epibenthic macrofauna. These organisms are generally greater than 1mm in size and live either on or within the surface sediments. As part of the ongoing monitoring studies of the existing CMPs, data on the epibenthic fauna in vicinity of the proposed CMPs have been extensively collected. Recent studies recorded species diversity as low in comparison to other areas in Hong Kong. Such characteristics have been attributed to periodic fluctuations in the physio-chemical environment associated with Pearl River run-off and high anthropogenic impact through intensive demersal trawling ([10]). Additional studies have also found the epibenthic faunal species within proximity to the proposed CMPs at South Brothers and East of Sha Chau to be composed of low commercial value bivalve, crab and shrimp species, commonly characterised by low abundance and diversity ([11]).

Following the EIAO-TM criteria, the ecological importance of the epifaunal assemblages both within, and within close proximity to the proposed CMPs at South Brothers and East of Sha Chau have been assessed in Table 4.8.

Table 4.8 Ecological Value of Epifaunal Assemblages at the proposed CMPs at South Brothers and East of Sha Chau

EIAO-TM Criteria	South Brothers	East of Sha Chau
Naturalness	The assemblages are expected to be disturbed due to fishing operations within these waters	The assemblages are expected to be disturbed due to fishing operations within these waters
Size	Total area of the temporarily affected subtidal habitats will involve approximately 164 hectares	Total area of the temporarily affected subtidal habitats will involve approximately 115 hectares
Diversity	The assemblages are of low diversity compared to the majority of other areas in Hong Kong	The assemblages are of low diversity compared to the majority of other areas in Hong Kong
Rarity	No organisms were found that are considered as rare	No organisms were found that are considered as rare
Re-creatibility	The habitat can be expected to recreate naturally within a relatively short timeframe	The habitat can be expected to recreate naturally within a relatively short timeframe
Fragmentation	The surrounding environment contains many other areas of similar substrate	The surrounding environment contains many other areas of similar substrate
Ecological Linkage	Epibenthic fauna act as a food source for demersal fisheries	Epibenthic fauna act as a food source for demersal fisheries
Potential Value	Unlikely that the site can develop conservation interest	Unlikely that the site can develop conservation interest
Nursery Ground	None identified	None identified
Age	The fauna appear to be typical of those present in Hong Kong's Epibenthic fauna assemblages	The fauna appear to be typical of those present in Hong Kong's Epibenthic fauna assemblages
Abundance	Abundance of epifauna is generally low in comparison to the majority of other areas in Hong Kong	Abundance of epifauna is generally low in comparison to the majority of other areas in Hong Kong
Summary	The subtidal epibenthic fauna assemblages within the proposed CMP at South Brothers are likely to be typical of common subtidal epibenthic fauna in Hong Kong with no rare species present.	The subtidal epibenthic fauna assemblages within the proposed CMP at East of Sha Chau are likely to be typical of common epibenthic fauna assemblages in Hong Kong with no rare species present.
Ecological Value	Low	Low

Intertidal Soft Bottom Habitats

Mangroves

Mangroves provide food, shelter and breeding grounds for a range of organisms including various pelagic and coastal fisheries, and birds ([12]). Three main mangrove stands are present within the Study Area located at Tung Chung Bay, Tai Ho Bay and Yam O. Within Tung Chung Bay, there are two separate stands, namely Tung Chung Bay itself and San Tau Beach (see Figure 4.3a). On the basis of the presence of locally rare mangroves and seagrass beds at San Tau Beach, this area covering approximately 2.7 ha has been designated as an SSSI and is discussed later in this section under the corresponding heading. One locally rare mangrove species has been recorded as present in Tung Chung Bay (San Tau Beach) during a Hong Kong wide study on mangrove habitats ([13]). However, due to the relatively large mangrove stand at this site (2.14 ha) and high floristic diversity (18 mangrove species and associated flora), this habitat ranked highly in comparison to other mangrove habitats in Hong Kong.

The mangrove habitat at Tai Ho Bay was found to be smaller in size (~1.9 ha) in comparison to that at Tung Chung Bay, with less floristic diversity (12 species of mangrove and associated flora) ([14]). The habitat is dominated by the relatively common mangrove Kandelia candel.

Mangrove habitats have also been recorded at Yam O, in the northeast of the Study Area which also support 2 small stands (~0.5 ha) ([15]). Of the two mangrove stands at Yam O, one at the Luk Keng entrance and one at Yam O Tuk (inner Yam O Bay), both were found to support moderate floristic diversity in comparison to other mangrove habitats in Hong Kong, particularly considering the small habitat size. However, both habitats appeared to be disturbed, possibly due to the log storage area works in close proximity to the site and the nearby Yam O reclamation works.

Following the EIAO-TM criteria, the ecological importance of mangrove habitats within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau has been assessed in Table 4.9.

Table 4.9 Ecological Value of Mangrove Habitats within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau

EIAO-TM Criteria	Mangrove Habitat
	Tung Chung Bay	Tai Ho Bay	Yam O Bay
Naturalness	The habitat is natural, although potentially affected by the Tung Chung Development	The habitat is natural	The habitat is natural, although potentially affected by the Yam O reclamation
Size	The 2 stands are both large (2.7 and 2.14ha)	Mangrove stand is medium in size (1.9ha)	Mangrove stand is small ~0.5ha
Diversity	Diversity is high in comparison to other mangroves in Hong Kong	Diversity is similar to other mangroves in Hong Kong	Diversity is moderate in comparison to other sites in Hong Kong
Rarity	One locally rare mangrove species has been recorded at San Tau Beach within Tung Chung Bay	No rare mangrove species recorded	No rare mangrove species recorded
Re-creatibility	Although re-creatable, the habitat may not return to it original status	Although re-creatable, the habitat may not return to it original status	Habitat is considered poor thus re-creatable
Fragmentation	The mangrove stand at this site is not fragmented	The mangrove stand at this site is not fragmented	The mangroves at this site are fragmented
Ecological Linkage	Site also includes mudflat, seagrass and horseshoe crab habitat	Site also includes mudflat, seagrass and horseshoe crab habitat	Site also includes mudflat and seagrass habitat
Potential Value	Mangroves provide high value habitat	Mangroves provide high value habitat	Mangroves provide high value habitat
Nursery Ground	Mangroves act as a nursery ground for many species	Mangroves act as a nursery ground for many species	Mangroves act as a nursery ground for many species
Age	Mangrove habitat are relatively slow growing	Mangrove habitat are relatively slow growing	Mangrove habitat are relatively slow growing
Abundance	Abundance of mangroves is high in comparison to other sites in Hong Kong	Abundance is similar to other mangroves in Hong Kong	Abundance is low in comparison to other sites in Hong Kong
Summary	The mangrove habitat has high species diversity and is large in comparison to other sites in Hong Kong. The site has associated mudflat and seagrass habitat and has been recorded as a nursery ground for horseshoe crabs in Hong Kong.	The mangrove habitat has medium species diversity in comparison to other sites in Hong Kong. The site has associated mudflat and seagrass habitat and has been recorded as a nursery ground for horseshoe crabs in Hong Kong.	The mangrove habitat is small in comparison to other sites in Hong Kong with moderate species diversity. The site has associated mudflat and seagrass habitat, however, is potentially under continued stress from nearby works.
Ecological Value	High	Medium	Low

Mudflats & Horseshoe Crab Habitats

Mudflats are classified as areas of fine-grained sediment (ie silt or fines) which lie between the high and low tide marks which are not covered by seagrass, mangroves or typical wetland vegetation and are generally fed with freshwater streams. Generally considered to be habitats of ecological importance, mudflats provide key breeding grounds for a variety of species, and species present there act as food source for both fish and, resident and wintering birds in Hong Kong.

Mudflats occur throughout Hong Kong, with the largest present in the Deep Bay area. Within the Study Area, each of the above locations described above for mangrove habitats also have mudflat habitats present (see Figure 4.3a). In addition of these mudflat habitats, those at Tung Chung Bay and Tai Ho Bay have been identified as having juvenile horseshoe crabs, namely the species Tachypleus tridentatus and Carcinoscorpius rotundicauda, recorded at each site ([16]) ([17]). In addition, recent surveys at Tai Ho Bay identified breeding pairs Carcinoscorpius rotundicauda present ([18]).

Following the EIAO-TM criteria, the ecological importance of mudflat habitats within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau has been assessed in Table 4.10.

Table 4.10 Ecological Value of Mudflat and Horseshoe Crab Habitats within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau

EIAO-TM Criteria	Mudflat and Horseshoe Crab Habitat
	Tung Chung Bay	Tai Ho Bay	Yam O Bay
Naturalness	The mudflats are natural but under stress from surrounding works and shellfish collection	The mudflats are natural	The mudflats are natural but under stress from surrounding works
Size	In comparison to other mudflats in Hong Kong the habitat is of medium size	In comparison to other mudflats in Hong Kong the habitat is of medium size	In comparison to other mudflats in Hong Kong the habitat is of small size
Diversity	In general species diversity on mudflats is high	In general species diversity on mudflats is high	In general species diversity on mudflats is high
Rarity	Two species of horseshoe crab have been identified as using these mudflats	Two species of horseshoe crab have been identified as using these mudflats	No rare species have been identified
Re-creatibility	The habitat can be expected to recreate naturally within a relatively short timeframe	The habitat can be expected to recreate naturally within a relatively short timeframe	The habitat can be expected to recreate naturally within a relatively short timeframe
Fragmentation	The mudflats at this site are relatively unfragmented	The mudflats at this site are relatively unfragmented	The mudflats at this site are relatively fragmented
Ecological Linkage	Site also contains mangroves and seagrass species	Site also contains mangroves and seagrass species	Site also contains mangroves and seagrass species
Potential Value	The site is of conservation interest	The site is of conservation interest	The site is of limited conservation interest due to small size and potential impact of nearby works
Nursery Ground	Mudflats act as a nursery ground for numerous species. Also identified as nursery ground for two species of horseshoe crab	Mudflats act as a nursery ground for numerous species. Also identified as nursery ground for two species of horseshoe crab	Mudflats act as a nursery ground for numerous species.
Age	Mudflats constantly accreting and eroding and the fauna present there are typically short lived	Mudflats constantly accreting and eroding and the fauna present there are typically short lived	Mudflats constantly accreting and eroding and the fauna present there are typically short lived
Abundance	Mudflats generally support organisms in high abundances in comparison to other marine habitats	Mudflats generally support organisms in high abundances in comparison to other marine habitats	Mudflats generally support organisms in high abundances in comparison to other marine habitats
Summary	The mudflats at Tung Chung Bay provide a nursery ground for horseshoe crabs in Hong Kong and have associated mangrove and seagrass habitat.	The mudflats at Tai Ho Bay provide a nursery ground for horseshoe crabs in Hong Kong and have associated mangrove and seagrass habitat.	The mudflats at Yam O Bay have associated mangrove and seagrass habitat, however, are under stress from nearby works
Ecological Value	Medium	High	Low

Seagrass

Seagrass beds occur in shallow, sheltered or subtidal areas and are recognised as areas of high biological productivity. They provide high value habitat as feeding and nursery ground for a range of marine species ([19]). Within Hong Kong, seagrass beds have been recorded with a very low distribution, occupying less than 0.1% of the total land area. Nevertheless, within the Study Area, three sites have been identified where seagrass beds have been recorded, namely San Tau, Tai Ho Bay and Yam O Bay ([20]) (see Figure 4.3a).

The mudflats at Yam O Bay and San Tau support seagrass beds of Halophila ovalis, with Zostera japonica also present at San Tau. Although the latter of these species has been recorded elsewhere in Hong Kong, San Tau represents this species only habitat, albeit of a relatively small size (15m²), on Lantau. In contrast, the seagrass beds (500m²) at Tai Ho Bay are seasonal and consist solely of the species Halophila beccarii. Studies on this species appear to indicate that the habitat is an important feeding ground for juvenile horseshoe crabs ([21]).

Following the EIAO-TM criteria, the ecological importance of seagrass beds within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau has been assessed in Table 4.11.

Table 4.11 Ecological Value of Seagrass Beds within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau

EIAO-TM Criteria	Seagrass Beds
	San Tau	Tai Ho Bay	Yam O Bay
Naturalness	The seagrass beds are natural but under stress from surrounding works and shellfish collection	The seagrass beds are natural	The seagrass beds are natural but under stress from surrounding works
Size	Size of the Zostera japonica bed is relatively small (15m^2) but the Halophila ovalis bed is large (2 ha)	Size of the seagrass bed is medium (500m^2)	Size of the seagrass bed is relatively large (~ 1 ha)
Diversity	In general, species diversity associated with seagrass beds is high	In general, species diversity associated with seagrass beds is high	In general, species diversity associated with seagrass beds is high
Rarity	Seagrass beds are relatively rare in Hong Kong. In addition, this site represents the only Zostera japonica habitat on Lantau. Two species of horseshoe crab have also been identified as using these seagrass beds	Seagrass beds are relatively rare in Hong Kong. In addition, two species of horseshoe crab have been identified as using these seagrass beds	Seagrass beds are relatively rare in Hong Kong.
Re-creatibility	Seagrass beds have been found to be difficult to re-create in Hong Kong	Seagrass beds have been found to be difficult to re-create in Hong Kong	Seagrass beds have been found to be difficult to re-create in Hong Kong
Fragmentation	The seagrass beds at this site are relatively unfragmented	The seagrass beds at this site are relatively unfragmented	The seagrass beds at this site are relatively unfragmented
Ecological Linkage	Site also contains mangroves and mudflat habitat	Site also contains mangroves and mudflat habitat	Site also contains mangroves and mudflat habitat
Potential Value	The site is of conservation interest	The site is of conservation interest	The site is of conservation interest
Nursery Ground	Seagrass beds act as a nursery ground for numerous species. Also identified as nursery ground for two species of horseshoe crab	Seagrass beds act as a nursery ground for numerous species. Also identified as nursery ground for two species of horseshoe crab	Seagrass beds act as a nursery ground for numerous species.
Age	The seagrass beds at this site are somewhat seasonal, therefore, relatively short-lived	The seagrass beds at this site are somewhat seasonal, therefore, relatively short-lived	The seagrass beds at this site are somewhat seasonal, therefore, relatively short-lived
Abundance	Seagrass at this site is of relatively low abundance	Seagrass at this site is of medium abundance	Seagrass at this site is of medium abundance
Summary	The seagrass beds atSan Tau within Tung Chung Bay provide a nursery ground for horseshoe crabs in Hong Kong and have associated mangrove and mudflat habitat. Although small in size, these seagrass beds are the only site on Lantau for Zostera japonica	The seagrass beds at Tai Ho Bay provide a nursery ground for horseshoe crabs in Hong Kong and have associated mangrove and mudflat habitat.	The seagrass beds at Yam O Bay have associated mangrove and mudflat habitat, however, are under stress from nearby works
Ecological Value	High	Medium	High

Hard Bottom Habitats

Subtidal Hard Bottom Habitats

As described above, the majority of the subtidal habitat within Hong Kong waters, including those within the Study Area, consists of soft bottom habitat. However, closer to the shoreline, the seabed will be commonly composed of hard bottom habitat, so much so that approximately 80% of Hong Kong's complex shorelines and many islands are composed of rocky outcrops. Of the numerous marine organisms that inhabit this substratum, corals, due to the protected status and ecological value, are of particular concern.

Over 80 species of coral occur in Hong Kong, with the highest diversities recorded in eastern waters. It appears that coral distribution in Hong Kong is primarily controlled by hydrodynamic conditions as Hong Kong’s western waters are influenced by the Pearl River, which lowers salinities and generally records higher concentrations of suspended solids. As such, the western waters of Hong Kong, in which the Study Area is located has previously been identified as being relatively devoid of coral species ([22]) ([23]).

Surveys of subtidal hard bottom habitats within the Study Area, excluding Artificial Seawalls (see below) have, however, indicated the presence of both hard and soft corals, albeit in both limited density and of limited diversity. Scattered hermatypic hard corals (family Faviidae), ahermatypic gorgonian seawhips and seapens have been identified within the Sha Chau and Lung Kwu Chau Marine Park, whereas, ahermatypic cup corals, soft corals such as Dendronephthya spp and seapens have also been recorded on the northern shore of the Study Area in the vicinity of Sham Tseng ([24]) ([25]).

Hermatypic hard corals possess vast numbers of symbiotic unicellular algae (zooxanthellae) within their endodermal lining. These photosynthesising algae require light for growth. The low salinity conditions coupled with high levels of suspended solids, which reduce light penetration, of the Study Area, reduce the potential for colonies of corals of high ecological value to be present.

Following the EIAO-TM criteria, the ecological importance of subtidal hard bottom habitats within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau has been assessed in Table 4.12.

Table 4.12 Ecological Value of Subtidal Hard Bottom Habitats within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau

EIAO-TM Criteria	Study Area
Naturalness	There is limited natural subtidal hard bottom habitat within the study area
Size	No subtidal hard bottom habitat will be permanently affected by the proposed works
Diversity	Due to the estuarine conditions, diverse assemblages are not expected to be present
Rarity	No rare species are expected to be present
Re-creatibility	Subtidal hard bottom habitats can be re-created
Fragmentation	The subtidal hard bottom habitat within the Study Area is fragmented
Ecological Linkage	The subtidal hard bottom habitats within the Study Area have low ecological linkage with habitats of conservation interest
Potential Value	Unlikely that these habitats can develop conservation interest within the Study Area
Nursery Ground	Unlikely that these habitats act as nursery grounds within the Study Area
Age	Subtidal hard bottom habitats within the study area are not expected to be mature
Abundance	Abundance of subtidal hard bottom associated species is expected to be low
Summary	Due to extensive development in the area, natural subtidal hard bottom habitat within the Study Area is limited. Artificial subtidal hard bottom habitat (eg seawalls) generally support less abundance and diversity than natural substratum. However, the estuarine conditions of the Study Area generally do not support subtidal hard bottom species of conservation interest.
Ecological Value	Low

Intertidal Hard Bottom Habitats

The majority of the coastal areas in the Study Area, although particularly in vicinity of the proposed CMPs at South Brothers and East of Sha Chau, have been reclaimed, thus in general artificial seawalls have replaced naturally occurring intertidal hard bottom habitats. The largest of these seawalls is at the Chek Lap Kok International Airport (see Figure 4.3a). Surveys have been conducted on the colonisation of organisms on artificial seawalls in Hong Kong and fouling organisms have been recorded as common on such artificial seawalls, wharf piles and other marine structures ([26]).

A relatively recent survey on the artificial seawall at the Chek Lap Kok International Airport found that colonisation had occurred by organisms such as polychaetes and bivalves, however, the habitat was considered to be in poor condition ([27]). Whilst colonisation of organisms considered to be of high ecological value, such as corals, has been recorded on artificial seawalls or structures in the waters in the east of Hong Kong, it is unlikely for the reasons stated above (see Subtidal Hard Bottom Habitats) that the artificial seawalls in the Study Area will be able to support high ecological value assemblages ([28]).

Following the EIAO-TM criteria, the ecological importance of intertidal hard bottom habitats within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau has been assessed in Table 4.13.

Table 4.13 Ecological Value of Intertidal Hard Bottom Habitats within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau

EIAO-TM Criteria	Study Area
Naturalness	There is limited natural intertidal hard bottom habitat within the study area
Size	No intertidal hard bottom habitat will be permanently affected by the proposed works
Diversity	Due to the estuarine conditions, diverse assemblages are not expected to be present
Rarity	No rare species are expected to be present
Re-creatibility	Intertidal hard bottom habitats can be re-created
	The intertidal hard bottom habitat within the Study Area is fragmented
Ecological Linkage	The intertidal hard bottom habitats within the Study Area have low ecological linkage with habitats of conservation interest
Potential Value	Unlikely that these habitats can develop conservation interest within the Study Area
Nursery Ground	Unlikely that these habitats act as nursery grounds within the Study Area
Age	Intertidal hard bottom habitats within the study area are not expected to be mature
Abundance	Abundance of intertidal hard bottom associated species is expected to be low
Summary	Due to extensive development in the area, natural intertidal hard bottom habitat within the Study Area is limited. Artificial intertidal hard bottom habitats (eg seawalls) generally support less abundance and diversity than natural substratum. However, the estuarine conditions of the Study Area generally do not support intertidal hard bottom species of conservation interest.
Ecological Value	Low

Marine Mammals

There are two resident species of cetacean in Hong Kong’s waters, the Finless Porpoise (Neophocaena phocaenoides) and the Indo-Pacific Humpback Dolphin, (Sousa chinensis). Recent studies appear to indicate that the Finless Porpoise only occurs in the southern and eastern waters of Hong Kong, with no sightings being recorded in the Study Area ([29]) (2) (3).

The distribution, abundance, habitat use, and life history of Indo-Pacific Humpback Dolphins in Hong Kong has been extensively studied since 1995 ([30])(4). The distribution and abundance of dolphins has been studied using line transect methods allowing any patterns to be determined. As sightings are obtained relative to known levels of search effort, corresponding densities have been obtained.

The line transect analysis of vessel surveys undertaken from 1995 to 2003 for the Indo-Pacific Humpback Dolphin Monitoring Programme showed that the abundance of dolphins is highest in the North Lantau area in all four seasons Figure 4.Figure 4.Figure4.3b.

Figure 4.3b Estimates of abundance of Indo-Pacific Humpback Dolphins in Hong Kong waters, based on line transect analysis of vessel surveys from 1995 to 2003 ([31])

In spring, almost all sightings of the Indo-Pacific Humpback Dolphins in Hong Kong have been made in North Lantau with a seasonal influx of individuals into South Lantau (and to a lesser extent, Deep Bay and East Lantau/Lamma areas) during summer, autumn and winter. The seasonal influx of Indo-Pacific Humpback Dolphins is thought to be due to the spread of freshwater from the Pearl River, directly to the west of Hong Kong ([32]). Indo-Pacific Humpback Dolphins are present in Hong Kong waters in their highest densities in summer and lowest in spring ([33]) ([34]). The proportion of the local population that utilize the North Lantau waters as opposed to other areas of Hong Kong varies from 72% in spring to 92% in winter when the abundance of Indo-Pacific Humpback Dolphins occurring in Hong Kong waters is at its lowest ([35]).

According to data from the Agriculture, Fisheries and Conservation Department, which has been collected between 1995 and 2004, it appears that the use of waters by Indo-Pacific Humpback Dolphins within the Study Area is not uniform (Figure 4Figure 4Figure 4.3c to Figure 4.Figure 4.Figure 4.3g). In all four seasons, Indo-Pacific Humpback Dolphins are most abundant in the western waters between Castle Peak and Black Point in the east and the islands of Sha Chau and Lung Kwu Chau in the west. High densities have also been recorded in areas to the north of the airport especially near the northeast corner and around the Brothers Islands ([36]).

Figure 4.3c Indo-Pacific Humpback Dolphin distribution in the Study Area in Spring (Data collected between 1995 and 2004) ([37]).

Figure 4.3d Indo-Pacific Humpback Dolphin distribution in the Study Area in Summer (Data collected between 1995 and 2004) ([38]).

Figure 4.3e Indo-Pacific Humpback Dolphin distribution in the Study Area in Autumn (Data collected between 1995 and 2004) ([39]).

Figure 4.3f Indo-Pacific Humpback Dolphin distribution in the Study Area in Winter (Data collected between 1995 and 2004) ([40]).

The exact status of the Hong Kong population of the Indo-Pacific Humpback Dolphin is not known with certainty. An analysis of recent dolphin data by Dr Thomas Jefferson for the present study comprises data collected between 1995 and mid 2002 appears to indicate that the population may be relatively stable, or at least that it is probably not decreasing at a rapid rate (Figure 4.3g) ([41]).

Studies have also revealed several areas of very low Indo-Pacific Humpback Dolphin density in the North Lantau area. One of these is the region along shore from Pillar Point to Brothers Point in the vicinity of the proposed CMPs at East of Sha Chau. Another such region is in the approximate location of the CMP at South Brothers, ie directly to the east of the airport platform and extending east along the Lantau coastline to Sham Shui Kok. Within this area very low numbers of dolphins have been sighted in comparison to other areas in North Lantau waters and in Hong Kong. It should also be noted that the coastline of West Lantau has densities of Indo-Pacific Humpback Dolphin among the highest known in Hong Kong Figure 4.3h.

Based on the review of baseline information on Indo-Pacific Humpback Dolphins in Hong Kong, it appears that the areas proposed for CMPs at South Brothers and East of Sha Chau have both recorded low sightings of dolphins in comparison to other areas in North Lantau and Hong Kong.

Following the EIAO-TM criteria, the ecological importance of the waters within the proposed CMPs at South Brothers and East of Sha Chau for marine mammals has been assessed in Table 4.14.

Figure 4.3g Trends in abundance of Indo-Pacific Humpback Dolphins in North Lantau (data collected between 1995 and 2002)

Figure 4.3h Distribution of Indo-Pacific Humpback Dolphin in Hong Kong

Table 4.14 Ecological Value of the Waters within the proposed CMPs at South Brothers and East of Sha Chau for Marine Mammals

EIAO-TM Criteria	South Brothers	East of Sha Chau
Naturalness	n/a	n/a
Size	Total area of the temporarily affected habitats is approximately 164 hectares	Total area of the temporarily affected habitats is approximately 115 hectares
Diversity	Only one species of marine mammal, Sousa chinensis, has been recorded within these waters	Only one species of marine mammal, Sousa chinensis, has been recorded within these waters
Rarity	Marine mammals are relatively common in western Hong Waters but are rarely sighted at the facility location	Marine mammals are relatively common in western Hong Waters but are less frequently sighted at the facility location
Re-creatibility	n/a	n/a
Fragmentation	This habitat is unfragmented	This habitat is unfragmented
Ecological Linkage	Areas of more frequent sightings are located to the west and northwest of the site	Areas of more frequent sightings are located to the west southwest and northwest of the site
Potential Value	Limited value due to relative small size in comparison to the more important marine mammal range areas to the west and northwest	Limited value due to relative small size in comparison to the more important marine mammal range areas to the west
Nursery Ground	The waters have not been identified as nursery grounds for marine mammals	The waters have not been identified as nursery grounds for marine mammals
Age	n/a	n/a
Abundance	Abundance of marine mammals within these waters are low to medium in comparison to other areas where marine mammals have been recorded in Hong Kong	Abundance of marine mammals within these waters are low to medium in comparison to other areas where marine mammals have been recorded in Hong Kong
Summary	The waters within the proposed CMP at South Brothers have relatively low sightings of marine mammals recorded in comparison to other sites in Hong Kong	The waters within the proposed CMP at East of Sha Chau have relatively low sightings of marine mammals recorded in comparison to other sites in Hong Kong
Ecological Value	Medium	Medium

Sites of Special Scientific Interest (SSSI)

Sites of Special Scientific Interest (SSSIs) may be land based or marine sites that are of special interest because of their flora, fauna, geographical, geological or physiographical features as identified by the AFCD. Hong Kong has a total of 51 SSSIs distributed throughout the region, of which two are found within the Study Area (see Figure 4.3a).

As described above, the intertidal marine habitat at San Tau supports mangrove stands, mudflats and seagrass beds. As such, this diverse habitat, which covers an area of approximately 2.7 ha, has been designated as an SSSI. The second of the SSSIs within the Study Area is the Lung Kwu Chau, Tree Island and Sha Chau SSSI and in within the Sha Chau and Lung Kwu Chau Marine Park, which is discussed below. .

Following the EIAO-TM criteria, the ecological importance of SSSIs within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau has been assessed in Table 4.15.

Table 4.15 Ecological Value of SSSIs within the Study Area for the proposed CMPs at South Brothers and East of Sha Chau

EIAO-TM Criteria	San Tau Beach SSSI	Lung Kwu Chau, Tree Island & Sha Chau SSSI
Naturalness	The SSSI at San Tau is natural under stress from surrounding works	The SSSI is natural and within the Marine Park
Size	No habitat will be lost through CMP works. SSSI is 2.7ha	No habitat will be lost through CMP works. The total land area of the SSSI is 78.7ha
Diversity	Species diversity within the SSSI is high	Species diversity within the SSSI would be expected to be relatively high
Rarity	Two species of horseshoe crab have been identified as using these mudflats as well as two species of seagrass	The SSSI is utilised during the winter by cormorants Phalacrocorax carbo
Re-creatibility	The SSSI would be expected to be difficult to recreate within a short timeframe	The SSSI would be expected to be difficult to recreate within a short timeframe
Fragmentation	The SSSI is relatively unfragmented	The SSSI is relatively unfragmented
Ecological Linkage	Site contains mangroves, mudflat habitat and seagrass species	The SSSI consists of numerous varying substratum but is land based
Potential Value	The site is of conservation interest	The site is of conservation interest and is designated within a Marine Park
Nursery Ground	The SSSI acts as a nursery ground for numerous species, including two species of horseshoe crab	The SSSI has been identified as night-time roosting site for cormorants
Age	Due to the nature of the habitat the substratum is accreting and eroding and the fauna present there are typically short lived	Not applicable
Abundance	The SSSI would be expected to support organisms in high abundances in comparison to other habitats	There are thought to be around 400 cormorants that roost during the winter.
Summary	The SSSI provides a nursery ground for horseshoe crabs in Hong Kong and has associated mangroves, mudflat habitat and seagrass beds	The SSSI provides night roosting opportunities for a large population of wintering cormorants.
Ecological Value	High	High

Marine Parks

There are currently four designated Marine Parks in Hong Kong waters and one Marine Reserve. The Sha Chau and Lung Kwu Chau Marine Park, is located within the Study Area (see Figure 4.3a). Covering an area of approximately 1,200 ha, the Marine Park encloses the Lung Kwu Chau, Tree Island and Sha Chau SSSI, which was designated for ornithological interest.

The marine environment of the Marine Park is greatly affected by the Pearl River freshwater run-off, with high organic loading and suspended sediments. As such, marine organisms that are present within these waters are highly adapted to salinity fluctuations with periods of continuous low salinity, and highly turbid environments. Nevertheless, the Marine Park acts as a protected habitat for fish species within the western waters and, according to recent surveys is an important feeding ground and nursery habitat for the Indo-Pacific Humpback Dolphin.

Following the EIAO-TM criteria, the ecological importance of the Sha Chau and Lung Kwu Chau Marine Park has been assessed in Table 4.16.

Table 4.16 Ecological Value of the Sha Chau and Lung Kwu Chau Marine Park

EIAO-TM Criteria	Sha Chau and Lung Kwu Chau Marine Park
Naturalness	The Marine Park is natural but under stress from surrounding works
Size	No habitat will be lost through CMP works. The MP covers 1,200ha
Diversity	Species diversity within the Marine Park would be expected to be relatively high
Rarity	The Marine Park is extensively utilised by Sousa chinensis and birds
Re-creatibility	The Marine Park would be expected to be difficult to recreate within a short timeframe
Fragmentation	The Marine Park is relatively unfragmented
Ecological Linkage	The Marine Park consists of numerous varying substratum
Potential Value	The Marine Park is of conservation interest
Nursery Ground	The Marine Park has been identified as acting as a nursery ground for Sousa chinensis
Age	Due to the estuarine conditions, the habitats within the Marine Park are not expected to be mature
Abundance	Due to it’s protected status the Marine Park would be expected to support organisms in high abundances in comparison to other habitats
Summary	Due to its designation and the use of the waters by Sousa chinensis the Marine Park is of conservation importance
Ecological Value	High

4.3.3 Marine Ecological Sensitive Receivers

The ecological value of each of the marine ecological habitats/organisms within the Study Area has been presented above based on the criteria presented in the EIAO-TM. A summary of the ecological values is presented below in Table 4.17. Based on these values, these habitats/organisms are determined whether or not they are considered to be a marine ecological sensitive receiver to the construction and operation of the proposed CMPs at South Brothers and East of Sha Chau.

Table 4.17 Marine Ecological Sensitive Receivers to the proposed CMPs at South Brothers and East of Sha Chau

Habitat/Organism		Ecological Value			Marine Sensitive Receiver
		South Brothers	East of Sha Chau	Study Area
Soft Bottom Habitats
Subtidal Soft Bottom Habitats
	Infaunal	Low	Low	n/a	û
	Epifaunal	Low	Low	n/a	û
Intertidal Soft Bottom Habitats
	Mangroves	n/a	n/a	Low to High	û^1
	Mudflats	n/a	n/a	Low to Medium	û^1,2
	Seagrass	n/a	n/a	Low to High	û^1
Hard Bottom Habitats
Subtidal Hard Bottom Habitats		n/a	n/a	Low	û
Intertidal Hard Bottom Habitats		n/a	n/a	Low	û
Marine Mammals		Medium	Medium	n/a	ü
Sites of Special Scientific Interest (SSSI)		n/a	n/a	High	ü
Marine Parks		n/a	n/a	High	ü
Notes: 1. High ecological habitat considered a marine sensitive receiver under the San Tau Beach SSSI and Yam O seagrass bed. 2. Due to it’s high ecological value Tai Ho Bay has been regarded as a marine sensitive receiver under SSSI.

4.4 Fisheries

This Section describes the baseline conditions of capture and culture fisheries resources within the Study Area. This area was defined in the Study Brief as the area for the Water Quality Impact Assessment. Consequently, this assessment of impacts has focussed on the fisheries resources and fishing operations of this area. Baseline conditions are evaluated based on information from the literature.

4.4.1 Literature Review

The availability of literature on the fisheries resources of the Study Area comes mainly from the AFCD 1996-1997 ([42]) and 2001-2002 Port Survey ([43]). Other relevant reports from the Study Area have been reviewed.

In Hong Kong, the commercial marine fishing industry is divided into capture and culture fisheries. To assess the capture fishery within the Study Area, the most up-to-date information on the Hong Kong fishery was consulted (1). Information from other relevant studies within the Study Area were also reviewed in order to determine if the areas are important nursery and spawning grounds for commercial fisheries (2).

The findings of fisheries surveys, fishermen’s interviews and accompanying literature reviews (3) conducted for AFCD’s Fisheries Resources and Fishing Operations in Hong Kong Waters Study have determined that commercial fish species reproduce throughout the year, though spawning for the majority of species appears to be concentrated during the period from June to September. The marine waters within the Study Area were not identified as a primary nursery ground for commercial fisheries but were noted as a spawning ground for Leiognathus brevirostris (shortnose ponyfish), Lateolabrax japonicus (sea bass) and Clupanodon punctatus (gizzard shad).

Capture Fisheries

In 2002, the estimated fisheries production in Hong Kong waters from both capture and culture fisheries amounted to 173,198 tonnes, valued at HK$ 1,700 million (4). Capture fisheries accounted for 98 % by weight (94.1 % by value) of the total production while the remaining 2 % (5.9% by value) corresponded to the culture sectors of the industry. Within Hong Kong waters, the highest yields for local fisheries within Hong Kong waters were mainly derived from the eastern and north-eastern coasts (5). The five most abundant fish species landed by weight from the capture sector were golden thread (Nemipterus virgatus 14%), lizardfish (Saurida sp 9%), big-eyes (Priacanthus sp 5%), scads (Decapterus sp 5%) and yellow belly (Nemipterus bathybius 4%).

Based on the latest AFCD Port Survey data (6), the highest range of fisheries production (ie 600 – 1000 kg ha^-1) was recorded near Cheung Chau, Penny’s Bay, Kau Yi Chau, Po Toi, Ninepin Group and Tap Mun. The top 10 families captured in Hong Kong were rabbitfish (Siganidae), sardine (Clupeidae), croaker (Sciaenidae), scad (Carangidae), squid, shrimp, anchovy (Engraulidae), crab, seabream (Sparidae) and threadfin bream (Nemipteridae).

For areas within the Study Area, the fisheries production ranged widely from <= 50 kg ha^-1 (for areas west of the Chek Lap Kok Airport) to 200 – 400 kg ha^-1 for areas near Sha Chau, Lung Kwu Chau and the Brothers (Siu Mo To) (7). These values are not in the high range for production in Hong Kong.

Up-to-date information from AFCD is available for use in this EIA and can be collated to allow an assessment be made of the importance of Fishing Zones in the Study Area to the Hong Kong fishery. The designated Fishing Zones within the Study Area have been identified and the importance of these zones is assessed and discussed below.

The Study Area interfaces with 14 Fishing Zones as identified in the AFCD Port Survey Report ^([44]). These Fishing Zones are identified as follows:

· Sha Lo Wan

· Tung Chung (South Brothers Study Area)

· Chek Lap Kok (South Brothers Study Area)

· Pak Mong (South Brothers Study Area)

· Sham Shui Kok

· Yam O

· The Brothers (East of Sha Chau Study Area and South Brothers Study Area)

· Lung Kwu Sha Chau

· Tai Lam Chung

· Pearl Island

· Castle Peak Bay

· Mong Hau Shek (East of Sha Chau Study Area)

· Tap Shek Kok (East of Sha Chau Study Area)

· Lung Kwu Tan

The area and number of vessels operating during 1996-1997 in each of the Fishing Zones is presented in Table 4.18. The total number of vessels varies widely from 20.8 in Lung Kwu Tan Fishing Zone to 256.9 in Lung Kwu Sha Chau Fishing Zone. Over 200 fishing vessels were reported to operate in The Brothers and Lung Kwu Sha Chau Fishing Zones and over 100 vessels were recorded for Sha Lo Wan, Sham Shui Kok and Yam O Fishing Zones. Except for Sha Lo Wan and Lung Kwu Sha Chau Fishing Zones where comparable numbers of < 15 m and > 15 m vessels were reported to operate in the fishing area, the other 12 fishing zones were found to be dominated by vessels < 15 m (Table 4.18).

According to the latest AFCD 2001-2002 Port Survey data, the most common type of vessel operating within the Study Area is sampan (P4/7) with particularly high numbers (100 - 400) recorded near Lung Kwu Chau, Sha Chau, The Brothers and along the northern coast of Lantau Island. Hang trawlers were reported to operate within the Study Area with relatively higher numbers (10 – 50) being reported near Sha Chau. Gill netters also operate in the area with numbers ranging from 0 to 50. Shrimp trawlers were found to operate throughout the Study Area with relatively higher numbers (100 - 200) reported near The Brothers. Relatively low numbers of other fishing vessels (<=10) such as stern trawler, pair trawler, long liner, hand liners and purse seiner and miscellaneous craft were also reported to operate within the Study Area. The information presented in indicates that the fisheries production levels vary markedly within the Study Area.

Of the 14 fishing zones identified, two of the fishing zones were ranked as recording high production (The Brothers 24^th and Lung Kwu Sha Chau 53^rd out of the 179 zones that reported a catch), seven recorded medium ranked catches (Sha Lo Wan 75^th, Pak Mong 78^th, Yam O 82^nd, Sham Shui Kok 89^th, Pearl Island 97^th, Tap Shek Kok 105^th and Tung Chung 106^th), and the remaining four zones recorded low catches including Castle Peak Bay 123^rd, Mong Hau Shek 135^th, Lung Kwu Tan 142^nd and Tai Lam Chung 148^th. Only one of the fishing zones reported fry catch (The Brothers) and ranked 76^th out of the 89 fishing zones that did report fry catches.

According to the AFCD Port Survey data ([45]), the top five adult fish species caught in this sector North of Lantau (SE02) included the mixed species, Caranx kalla (scad), Clupanodon punctatus (gizzard shad), Sardinella jussieu (sardine) and Argyrosomus spp (croaker). The main fish species reported in catches from the Study Area are of low commercial value including mixed species (juveniles of trash fish species such as pony fish, scad, rabbitfish and sardine) (Table 4.20). Only the silver shrimp is regarded as of high commercial value. Shrimp scad, hair tail, rock fish, sea bream, conger pike eel, mantis shrimp and prawn are regarded as of medium commercial value.

A recent demersal trawl survey, conducted in May 2001 at locations within the Study Area at sites around Lung Kwu Chau and around the mud pits as part of the ongoing EM&A for the contaminated mud pits at East Sha Chau ([46]) , recorded a total of 186 different species . Of these species, crabs, fish, gastropods, mantis shrimp, prawns and shrimps were the most abundant. Crabs were numerically dominant in these waters (a total of 7,028 individuals were recorded) with Charybdis japonica and Charybdis affinis being the most abundant species at locations near the mud pits.

A total of 2,225 individuals representing 72 fish species were recorded in the trawl survey. The most common fish recorded within the Study Area near the mud pits were the pony fish (Leiognathus brevirostris), the croaker (Johnius belangerii) and another croaker Johnius macrorhynus. The commercially important mantis shrimps (mostly Oratosquilla interrupta) and prawn (Penaeus japonicus) were also abundant.

Table 4.18 Area (Ha) and Number of Vessels Operating During 1996 - 1997 in Each AFCD Fishing Zone within the Study Area

Code	Fishery Area	Area (Ha)	Vessels < 15 m	Vessels > 15 m	All Vessels
18	Sha Lo Wan	961.00	72.7	77.7	150.4
19	Tung Chung	363.42	44.3	13.6	57.9
20	Chek Lap Kok
21	Pak Mong	533.22	47.1	21.9	69.1
22	Sham Shui Kok	531.60	135.8	15.3	151.1
23	Yam O	529.94	115.8	8.3	124.1
32	The Brothers	1,804.78	154.5	92.1	246.6
33	Lung Kwu Sha Chau	3,616.46	126.5	130.4	256.9
39	Tai Lam Chung	370.36	20.3	2.3	22.5
40	Pearl Island	286.83	13.1	5.7	18.8
41	Castle Peak Bay	579.77	28.7	10.2	38.9
42	Mong Hau Shek	1,329.63	41.0	22.5	63.6
43	Tap Shek Kok	822.57	73.5	19.2	92.7
44	Lung Kwu Tan	457.72	16.4	4.4	20.8
Total		12,187.3	*	*	*
Total of all Fishing Zones in Hong Kong		181,791	2,267	260	2,527
Percentage of Hong Kong Total		6.7%	*	*	*
* No values can be calculated for these parameters from the information provided as it cannot be determined whether the vessels reported as operating within one zone are the same vessels that are reported for another zone.

Table 4.19 Total Value ($), Adult Catch (kg) and Fry Catch (tails) Displayed on a Total Production, Production (Ha^-1) and Rank (Ha^-1) Basis for the AFCD Fishing Zones in the Study Area (1996 - 1997 Port Survey)

Code	Fishing Area	Total Production		Production (Ha^-1)			Rank Production (Ha^-1)
		Adult Fish (kg)	Fry (tails)		Adult Fish (kg)	Fry (tails)		Adult Fish (out of 179)	Fry (out of 89)
18	Sha Lo Wan	133,449.64	-		137.82	-		75	-
19	Tung Chung	28,662.43	-		78.87	-		106	-
21	Pak Mong	66,410.08	-		124.55	-		78	-
22	Sham Shui Kok	56,328.52	-		105.96	-		89	-
23	Yam O	63,008.77	-		118.90	-		82	-
32	The Brothers	570,682.23	22,983.87		316.21	12.74		24	76
33	Lung Kwu Sha Chau	651,700.01	-		180.20	-		53	-
39	Tai Lam Chung	7,908.49	-		21.35	-		148	-
40	Pearl Island	27,182.04	-		94.77	-		97	-
41	Castle Peak Bay	32,613.09	-		56.25	-		123	-
42	Mong Hau Shek	51,652.2	-		38.85	-		135	-
43	Tap Shek Kok	66,218.32	-		80.50	-		105	-
44	Lung Kwu Tan	14,336.79	-		31.32	-		142	-

Table 4.20 Top Five Adult Fish (by weight) Caught in Each AFCD Fishing Zone within the waters of the Study Area (1996 - 1997 Port Survey)

Code	Fishing Area	Top Five Fish Caught (by weight)
		Species	Common Name
18	Sha Lo Wan	Mixed Species	Mixed Species
		Caranx kalla	Shrimp Scad
		Sardinella jussieu	Sardine
		Trichiurus haumela	Hair Tail
		Argyrosomus spp	Croaker
19	Tung Chung	Caranx kalla	Shrimp Scad
		Mixed Species	Mixed Species
		Trichiurus haumela	Hair Tail
		Portunus sanguinolentus	3-Spot Crab
		Sardinella jussieu	Sardine
21	Pak Mong	Mixed Species	Mixed Species
		Collichthys lucida	Lion Head
		Caranx kalla	Shrimp Scad
		Trichiurus haumela	Hair Tail
		Argyrosomus spp	Croaker
22	Sham Shui Kok	Mixed Species	Mixed Species
		Sebasticus marmoratus	Rockfish
		Caranx kalla	Shrimp Scad
		Argyrosomus spp	Croaker
		Trichiurus haumela	Hair Tail
23	Yam O	Mixed Species	Mixed Species
		Sebasticus marmoratus	Rockfish
		Clupanodon punctatus	Gizzard Shad
		Mugil Affinis	Mullet
		Sparidae spp	Sea Bream
32	The Brothers	Mixed Species	Mixed Species
		Caranx kalla	Shrimp Scad
		Sardinella jussieu	Sardine
		Clupanodon punctatus	Gizzard Shad
		Decapterus lajang	Scad
33	Lung Kwu Sha Chau	Mixed Species	Mixed Species
		Caranx kalla	Shrimp Scad
		Clupanodon punctatus	Gizzard Shad
		Sardinella jussieu	Sardine
		Trichiurus haumela	Hair Tail
39	Tai Lam Chung	Acetes spp	Silver Shrimp
		Muraenosox cinereus	Conger Pike Eel
		Mixed Species	Mixed Species
		Sebasticus marmoratus	Rockfish
		Argyrosomus spp	Croaker
40	Pearl Island	Mixed Species	Mixed Species
		Acetes spp	Silver Shrimp
		Stromateoides argenteus	White Pomfret
		Trachurus japonicus	Scad
		Oratosquilla oratoria	Mantis Shrimp
41	Castle Peak Bay	Mixed Species	Mixed Species
		Oratosquilla oratoria	Mantis Shrimp
		Argyrosomus spp	Croaker
		Parapenaeopsis hungerfordi	Prawn
		Psenopsis anomala	Melon Seed
42	Mong Hau Shek	Mixed Species	Mixed Species
		Clupanodon punctatus	Gizzard Shad
		Mugil Affinis	Mullet
		Caranx kalla	Shrimp Scad
		Oratosquilla oratoria	Mantis Shrimp
43	Tap Shek Kok	Mixed Species	Mixed Species
		Clupanodon punctatus	Gizzard Shad
		Collichthys lucida	Lion Head
		Argyrosomus spp	Croaker
		Mugil Affinis	Mullet
44	Lung Kwu Tan	Sardinella jussieu	Sardine
		Mixed Species	Mixed Species
		Caranx kalla	Shrimp Scad
		Collichthys lucida	Lion Head
		Siganus oramin	Rabbitfish

Culture Fisheries

The closest AFCD designated Fish Culture Zone (FCZ) to the Study Area is located at Ma Wan which is approximately 2.3 km from the eastern edge of the Study Area for water quality assessment. Information from AFCD indicates that the Ma Wan FCZ consists of 127 licensed rafts with a total licensed area of 14,554 m² (total gazetted area = 46,300 m²). The main species cultured are the spotted grouper (Epinephelus chlorostigma), gold-lined seabream (Rhabdosargus sarba), mangrove snapper (Lutjanus argentimaculatus) and the pompano (Trachinotus blochii). There is no figure available for production at this FCZ.

Artificial Reefs

Two artificial reef sites have been identified within the Study Area. One of them is located east of the Chek Lap Kok Airport within the Chek Lap Kok Marine Exclusion Zone (AR1) and the other is within the Sha Chau and Lung Kwu Chau Marine Park (AR2). AR1 was deployed in May 2000 and has a footprint area of 1,200 m² and a space area of 3,600 m^{2 ([47])}. AR2 was deployed in March 2000 with a footprint and space area of 3,600 m² and 5,580 m², respectively ([48]). AR2 was deployed as part of the mitigation for the temporary aviation fuel line at Sha Chau in the Sha Chau and Lung Kwu Chau Marine Park. The deployed artificial reefs provide hard surfaces for colonization of invertebrates, including barnacles, bivalves, tube worms, sponges, bryozoans and squirts (tunicates). They also provide habitats for juveniles of many high value reef fish, including bream, snapper and sweetlip/grunt. Both artificial reef complexes (AR1 and AR2) are designed to enhance fisheries resources and promote feeding opportunities for the Indo-Pacific Humpback Dolphin.

The surveys conducted at AR2 as part of the Sha Chau and Lung Kwu Chau Marine Park Monitoring Programme during 2000 – 2001 showed an increase in fish abundance and diversity around the AR after its deployment ([49]). Species of commercial value such as Otolithes ruber (Toothed Croaker) was recorded in higher numbers around the AR area. A higher abundance and diversity in benthic fauna than control stations was recorded in one of the AR sites within the marine park. The results of the monitoring programme have provided evidence of the beneficial effect of AR2 to the marine ecology of the Sha Chau and Lung Kwu Chau Marine Park and potentially the feeding opportunities for the dolphins using the marine park area ([50]).

Based on the above review, the two artificial reefs within the Study Area are regarded as key sensitive receivers for the proposed project.

4.4.2 Fisheries Importance

The importance of the fisheries within the Study Area is addressed based on the baseline information provided above. The Fishing Zones within the Study Area are characterised as mainly of medium and low value, however, two were of high value (The Brothers and Lung Kwu Sha Chau). The catches from these zones were composed of juvenile mixed species, which are used as fish feed in mariculture.

The EIAO TM (Annex 9) states that spawning areas can be regarded as an important habitat type as they are critical to the regeneration and long term survival of many organisms and their populations. Consequently the seasonal spawning ground in the northwestern waters can be considered as important to fisheries.

4.4.3 Sensitive Receivers

Based on the preceding review of the available information on the capture and culture fisheries of the waters of the Study Area and its immediate vicinity, the sensitive receivers which may be affected by the proposed works associated with the Project are identified as follows:

· Fish Culture Zone at Ma Wan;

· The seasonal spawning ground in Northwestern waters ([51]) ; and,

· The two artificial reef complexes (Airport and Marine Park).

The locations of the sensitive receivers identified above are shown in Figure 4.2b.

4.5 Noise

4.5.1 Baseline Conditions

Both proposed CMPs (East of Sha Chau and South Brothers) are located to the south of Tuen Mun, with East of Sha Chau located approximately 3.2 km to the northeast of the Hong Kong International Airport (HKIA) and the South Brothers site located approximately 2 km to the east of the HKIA. North Lantau New Town is located to the south of the Study Areas.

Both Study Areas are directly under the flight paths of the HKIA. The proposed CMPs at East of Sha Chau and South Brothers are under 25R and 07R respectively. Hence, aircraft noise has dominant effects on the local noise climate. With reference to the information published by the Civil Aviation Department (CAD), the East of Sha Chau and South Brothers pits are within Noise Exposure Forecast (NEF) 25 zone at the ultimate capacity of the HKIA. The southern portion of East of Sha Chau and the northern part of the South Brothers CMP’s fall within NEF 30 zone.

In addition, road traffic noise emissions associated with the North Lantau Expressway and operation of the Lantau Airport Railway (LAR) are other noise sources contributing to the overall ambient noise levels.

Frequent movements of marine vessels (e.g. service between Tuen Mun and Tung Chung) in and around the Study Areas also contribute to the overall ambient noise levels.

4.5.2 Noise Sensitive Receivers

The NSRs in the vicinity of the Study Areas have been identified with reference to the most updated survey sheets and development plans. The identified NSRs and their respective distances to the boundary of the Study Areas, are given in Table 4.21 below. These NSR locations are also illustrated in Figure 4.5a. As the Pillar Point Refugee Camp has been closed, it is no longer regarded as a NSR. Also, the Lantau Logistics Park (LLP) is proposed on a reclamation outside Siu Ho Wan Depot, and hence no NSRs would be located at the LLP.

Table 4.21 Noise Sensitive Receivers near the Study Areas

NSR	NSR Type	Uses	ASR	Approx. Distance to East of Sha Chau Pits	Approx. Distance to South Brothers Pits
N1	Regal Airport Hotel	Hotel	C	2000 m	2980 m
N2	Seaview Crescent in Tung Chung	Residential	B	4700 m	2930 m
N3	Monterey Cove in Tung Chung	Residential	B	4600 m	2310 m
N4	Planned R(B)6 Residential Area at Area 77b (in Kei Tau Kok)	Residential	B	4000 m	1510 m
N5	Ho Yu School	School	B	4700 m	2090 m
N6	Planned Residential Area at Area 77 (in Kei Tau Kok)	School	B	4090 m	622 m

As N1 is located to the northeast of HKIA and directly affected by noise from the airport operations and the flights, the Area Sensitivity Ratings (ASR) are regarded as 'C'. NSRs N2, N3, N4, N5 and N6 are situated in Tung Chung New Town facing the proposed South Brothers facility directly. However, as N2, N3, N4, N5 and N6 are located more than 500 m from the HKIA, noise from the land-base operation and activities of the HKIA would not significantly influence to these NSRs. ASR "B" is therefore assumed for NSRs N2, N3, N4, N5 and N6.

4.6 Cultural Heritage

4.6.1 South Brothers 2 and East Sha Chau 1 Characteristics

The project covers two areas (see Part 1, Figures 2.4a and 2.4b):

· an area of seabed known as East Sha Chau 1 (ESC 1)—to the north of Chek Lap Kok; and

· South Brothers 2 (SB 2) an area of seabed to the east of Chek Lap Kok, north of Lantau Island.

4.6.2 Geology

Generally, the submarine deposits in the Hong Kong region are subdivided into three formations, Chek Lap Kok Formations and the overlying Hang Hau Formations.

The Chek Lap Kok Formations, the lowest part of the Quaternary succession are considered to be Middle to Late Pleistocene in age and consists of colluvium, alluvium and lacustrine sediments Fyfe, et.al., (2000). The marine sediments on top of this formation are sediments related to the Holocene period (from about 13,000 BP to the present day) and referred to as the Hang Hau Formations consisting of clayey silt sediments and some sand (mud, sandy mud).

The Sham Wat Formation, found between Chek Lap Kok Formations and Hang Hau Formations is considered to be the Eemian deposit with uncertain age and consisting of soft to firm silty clays with yellowish mottling. This formation is presently not widespread but only in a subcrop beneath the Hang Hau Formation (Fyfe, et.al. 2000).

More modern sediments are related to the discharge from the Pearl River, (and which would have an effect on the project area, being located down stream from the mouth of the Pearl River) having a seasonal discharge of about 370,000 million cubic metres each year (ibid). They consist of sand, mud and some gravel.

Fyfe, et.al (2000) further explains the rate of sedimentation:

“In general, present day sedimentation rates in Hong Kong waters are low, though they were undoubtedly greater earlier in the Holocene when sea level was rising rapidly. … Without tidal flushing, the sediment entering Victoria Harbour from the Pearl River, sewage solids and losses from dredging and reclamation might be expected to raise the seabed level by 40mm per year. However, comparison of Hydrographic charts of Victoria Harbour from 1903 to 1980 revealed no conclusive evidence of net sedimentation, implying that the seabed is a state of dynamic equilibrium. Assuming that sedimentation in Hong Kong waters began about 8 000 years ago, deposition of the 10 to 20 m of marine mud must have occurred at an average sedimentation rate of between 1.25 and 2.5 mm per year. Available evidence indicates that the rate of Holocene sedimentation has not been steady. Radiocarbon dating suggests that the majority of sedimentation has taken place over the past 4 000 to 5 000 years.”

During the late Pleistocene period (18,000BP) sea levels began to rise until about 6,000 years BP and which is about the level of present day sea level. “The extent of the rise could be as great as perhaps 140 metres in parts” (ibid: 40).

The sediments of the Late Holocene period, considered to be relatively homogenous very soft to soft silty clay and with high moisture content, offers the greatest potential (as compared to the surface of the seabed which is often found to have been disturbed by fishing and other shipping related activities) to include well preserved remains associated with the occupation and use of the islands in Hong Kong waters. These remains could include shipwrecks.

The coverage of the Hang Hau Formation in SB 2 varies from 17m to 25m and there is a band of about 10m of marine deposits, in ESC 1 it is unknown. The ESC 1 area under investigation in this study is adjacent to four groups of pits that have been used for the storage of contaminated mud. These pits use the following design features (ibid):

· The pit would be dredged to the base of the soft geological deposits, ie the Hang Hau and Sham Wat formations. This differs from CMP IV which extended deeper into pre-Holocene sand deposits.

· The pit would be dredged to a commonly adopted rule of thumb side slope of 1:3.

· Through hydrodynamic assessments made of previous purpose dredged CADs the pits are assumed to be backfilled with contaminated sediments to a level of 3 metres below the surrounding seabed level.

· On completion of backfilling, the contaminated sediments would be capped with 3 metres of uncontaminated mud subject to change upon detailed assessment to be carried out in a later stage. It is noted that the capped mud pits have been demonstrated to become colonised by benthic fauna similar to the natural surrounding seabed ([52]).

In the South Brothers project area the water depth varies from 7m to 11m below sea level (mPD), in the ESC 1 project area the depth varies from approximately 5.5m to 7.5m below sea level (PD).

4.6.3 Archaeological/Historical Background

Archaeological evidence indicates that seafarers have used the waters of Hong Kong for around 6,000 years (Bard, 1988). In Chau (1993) it is reported that:

“In the past decade, a great number of prehistoric sites have been discovered in the coastal sandbars which represent the opening up of the coastal and offshore island areas by the early settlers. Around six thousand years ago, the Neolithic folks had already settled in the coastal area of South China.”

Coates (in Braga, 1957) stated that “Definite archaeological traces of this prehistoric activity have been found … on the beach at Shek Pik, on the south coast of Lantao [Lantau] Island. From these finds it is clear that about three thousand years ago the islands were used as a seasonal entrepôt for trade between the Yangtse mouth, the tribal states of what is to-day Kwangtung Province, and Indonesia.” The islands at the mouth of the Pearl River were seen as more suitable for trade between the Cantonese merchants and those from other regions, and “Temporary settlements were built near the beaches. Cooking utensils have been found from this period on Lamma and Lantao, but no trace of buildings.”

Further information states that:

“Local history, still very far from being recorded fully, begins with the migration of Chinese into the area during the Sung dynasty (960-1279). … Lantao Island is the next of the group to appear in history. The last reigning Sung emporer, Ti-ping, made Kowloon his rallying point in the long Chinese retreat before the Mongol invasion. In 1279, not far from Tsuen Wan, his forces met the Mongols and were finally defeated. After the battle large numbers of the Court and nobility escaped across the comparatively narrow, sheltered stretch of water to Lantao. … Of those who fled to Lantao, there were those who settled and possibly intermarried with the inhabitants, traces of these cultured refugees are to be found at Tai O. … The Mongols did not enjoy for long their conquest of South China. The early part of the fourteenth century was a troubled time in the South, and from the Kowloon peninsula a number of families moved to safety in remoter spots. The families at present occupying villages in the Shek Pik area of Lantao moved there during the period of Mongol rule (1279-1368).”(ibid).

Meacham (1994) noted that “The history of Chek Lap Kok [approximately 2 km’s to the west of SB2] spans the entire period of human occupation in the Hong Kong area, from the earliest inhabitants of the painted pottery period around 4000 BC to the recent period.” As part of the rescue archaeological project carried out on Chek Lap Kok before the construction of the international airport, archaeological work was carried out on several sites on Chek Lap Kok, including a 8^th-10^th century site encompassing kilns and coins; burial sites of the Northern Sung period; a site containing pottery from the Middle and Late Neolithic period (4000-1500 BC); burial/ritual sites dated 3700-3400 BC; a number of Tang lime kilns (dated 750 and 1200 AD); and a site containing hard and soft geometric pattern pottery, axe moulds and cloth from the Bronze age. In 1993, part of a cannon was discovered during dredging of the seabed between Chek Lap Kok and Tung Chung (Meacham, 1994). The discovery was then reported to the Provisional Airport Authority. Inscriptions found on the cannon revealed that it was manufacturing in 1808. This cannon is likely related to the fort at Tung Chung, reflecting the Chinese military presence in the area in the past.

Lantau Island, just to the south of the Study Areas, is the largest and most western of the islands in the Hong Kong group of islands and therefore provides shelter for the waters between it and Hong Kong Island. Being located at the outlet of the Pearl River “…rightly called the artery of Southern China” (Lo, 1963) the area had “…established contacts with the outer world by the Chin Dynasty (ibid: 2). An early maritime industry was the pearl fishing industry and “…governmental control of this activity only began in the time of the Five Dynasties…” (Lo, 1963). Lantau Island also became a prolific incense-producing district, although “…nothing remains of it to recall the origin of the name Hong Kong (i.e. Fragrant Port)” (ibid). The bay inside of Lantau Island attracted “…trading vessels from Arabia, Persia, India, IndoChina, and the East Indies…” (ibid), and local vessels involved in the fishing and salt making industries. Pirates were prolific in the area, as well as settling on Lantau Island, and forts and batteries were also built on the island to assist the Imperial Navy in controlling pirates.

It is only a few miles north of the project area, ie. Lin Tin (Neilingding) and Tuen Mun, that the Portuguese (the first European arrivals) established a presence there in 1513. The Portuguese explorer, Jorge Alvares was permitted to land on Lin Tin and for “…about ten months he spent in the Canton River, at the anchorage of T’un Men…” as this was “…where all the foreign trade in south China was conducted (Braga, 1965). “ Landward and closer to him, across the stretch of waters to the east, he could see towering Ching Shan (now known as ‘Castle Peak’) standing guard over the anchorage of T’un Men. A little to the north, the headland of Nan Shan reared its form protecting the naval station of Nan Tou, with the Imperial junks lying at anchor, under the guns of the fort on little Ta Shan Island; and a considerable movement of ships at the port of Nan Tou showed that it was an important town.” (ibid).

Further on this discovery of China by Europeans and containing an account of the significance of this area for trade in general can be found in a report by Tomé Pires (Cortesão, 1944) a Portuguese living in Malacca and which is “…based possibly to some extent on information gathered by Jorge Alvares in China.” (ibid). “…Pires has a lot to say about the ports and the peoples who traded in China. He mentions that junks from Malacca anchor “in the port of Tumon.” Those from Siam anchor, he states “in the port of Hucham.” Our port of Tumon is three leagues nearer to China than the Siamese one.” If our theory is correct that the island of Tumon is none other than Lin Tin Island, then it is likely that Hucham would be the port of Lantao Island.” (ibid). Cortesão in Braga (1965) states “The city of Canton (Quamton) is where the whole kingdom of China unloads all its merchandise…” and “Salt is a great merchandise among the Chinese. It is distributed from China to these regions; and it is dealt with by fifteen hundred junks which come to buy it, and it is loaded in China to go to other places.” (ibid).

Lo (1963) further illustrates the importance of the area surrounding the Study Area:

Though the trading contacts of T’un-mên with overseas countries can be traced back to quite ancient times—probably beginning in the Liu Sung period—it was during the T’ang Dynasty that trade greatly extended. … As traffic increased and more travellers passed through T’un-mên literary men began to learn of this place and its trading activities.

The sovereign of Nan Han who seized power during the disintergration of the T’ang and established himself in southern China made it his policy to secure the support of outlaws, to extend his sway to the non-Chinese peoples, the Mans and the Tans (people who live on boats) and to derive the maximum profit from with foreign countries. Consequently special attention was paid to T’un-mên. When the Five Dynasties came to an end and the Sung emporers ascended the throne, governmental machinery in the T’un-mên area was elaborated. In addition to the royal garrison, an officer whose duty was to pursue and arrest bandits was installed.A system of administration for the land-locked waters and more remote seas was put into force at T’un-mên and two other posts (one at P’i-p’a Chou at the northern tip of Lantau Island, and one at Tan-kan Chou of Ju-chou). …during the Sung only three places on the coast round the outlet for Canton, namely T’un-mên, Kuan-fu Ch’ang and Ta-Yu Shan (Lantau) were guarded by imperial troops.

It is evident that the region between Lantau and Lintin and T’un-mên—the region that takes in the Study Area for the mud disposal was populated, and active in the movement of people and materials between various parts of China, and several other nations, over a period of at least 4000 years.

4.6.4 Contemporary Description

A brief contemporary description of the area around Chek Lap Kok can be found in Hownam-Meek (1978):

“Tung Chung Bay mostly dies at low water and you keep to the N of the Red and White buoy there at all times. There is a government pier at Ma Wan Chung and a pleasant walk will take you to the old Chinese sort, now a school, which still has cannon sticking through the walls. It is perhaps difficult to imagine that Tung Chung used to be the chief village of Lantao at which time no doubt its bay had more water than now. There is now a thriving village near the pier at Ma Wan Chung. Sampan ferries connect Ma Wan Chung to the nearby beaches of Chek Lap Kok. There is a beautiful beach in the bay SA of Red Pt [on Chek Lap Kok] with an unusual rock formation on its W side. There are small sandy bays on the NW shore of Chek Lap Kok; one has a concrete pier. Either side of Chu Lu Kok (Chek Lap Kok) makes a good anchorage, depending on the wind. The bottom is soft mud so it doesn’t matter if, at low water, you touch…”

“ To the N of Lantao lie the Brothers, the Western of which has an abandoned graphite mine on its W side. ... The whole area to the North of Lantao is now occupied by shipping laid up as a result of the recession. … A mile S x E of Tung Ku lies the attractive Sha Chau, a series of rocky cones standing on the sandpits. There is a tiny Joss House on one islet and a good anchorage under the lee in 1.5 to 2 fathoms mud. The beaches are completely deserted.”

4.6.5 Review of Charts

A review of a number of charts was carried out to ascertain if there were any other written records of shipwrecks in the ESC 1 and SB 2 area.

Shipwrecks are predominantly the primary archaeological site located underwater (Muckelroy, 1978). Since they are random and haphazard events it is difficult to predict their exact location as little written references survive or were ever made.

British Admiralty Charts 342 (published 1962), 341 and 1919 (published 1989), and 1503 (published 2002) highlight one wreck in the ESC 1 area, but only on BA 342. The wreck did not appear on the later charts.

Information from the Hong Kong Hydrographic Office

Contact was made with the Hong Kong Hydrographic Office and upon checking their records, they found two “suspected wreckages”, the closest to the Study Area being about one nautical mile to the west of East Sha Chau.

Information from the United Kingdom Hydrographic Office

Contact was made with the United Kingdom Hydrographic Office and they provided information about two ‘live’ shipwrecks within three nautical miles of a location between the two Study Areas. The closest shipwreck is about one nautical mile from the western edge of East Sha Chau, being the same shipwreck as that reported from the Hong Kong Hydrographic Office.

4.7 Baseline Review Findings

Although the baseline review of the literature found the Study Area has potential for underwater cultural heritage sites, no sites of historical or archaeological significance have been identified from the literature, or the charts of the Study Area.

Contents

4 Baseline Conditions & Sensitive Receivers 1

4.1 Introduction 1

4.2 Water Quality 1

4.3 Marine Ecology 10

4.4 Fisheries 3136

4.5 Noise 3145

4.6 Cultural Heritage 3147

4.7 Baseline Review Findings 3152

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^{([1]) CES & BCL (1994). East Sha Chau Monitoring Programme, Final Report (November 1992 - December 1993).}

^{([2]) Hydraulics and Water Research (Asia) Ltd (1993). Disposal of Contaminated Mud at East Sha Chau: An Assessment of the Stability of Dumped Spoil and Capping Layers.}

^{([3]) Refer to Annex A, Appendix A for a summary of the field investigation work within Tai Ho Bay. Full details of the survey are presented in EGS Asia Limited (2004). Water Quality Monitoring and Site Measurements at Tai Ho Wan, Lantau. Final Report (HK188304) to the Civil Engineering and Development Department, July 2004.}

^{([4]) Environmental Protection Department (2002) Marine Water Quality in Hong Kong 2001.}

^{([5]) Agreement No. CE 44/97. Environmental Monitoring and Audit of Contaminated Mud Pit IV at East of Sha Chau.}

^{([6]) City University of Hong Kong (2001) Agreement No. CE 62/98, Consultancy Study on Fisheries and Marine Ecological Criteria for Impact Assessment, Final Report, for the Agriculture, Fisheries and Conservation Department, Hong Kong SAR Government.}

^{([7]) CityU Professional Services Limited (2002) Agreement No. CE 69/2000 - Consultancy Study on Marine Benthic Communities in Hong Kong. Final Report. Submitted to the Agriculture, Fisheries and Conservation Department. Hong Kong SAR Government.}

^{([8]) Whilst a number of other studies from within the Study Area provide details on the benthic assemblages that were present at the time study was undertaken (ie Agreement No. CE 44/97) it has been decided that the above cited reference provides the most up-to-date information, allows a direct comparison with benthic assemblages throughout Hong Kong, and is not tailored towards an a priori monitoring objective.}

^{([9]) CityU Professional Services Limited (2002) Op cit.}

^{([10]) Mouchel Asia Limited (2002) Agreement No CEO 01/2001 - Environmental Assessment Study for Backfilling of Marine Borrow Pits at North of the Brothers. Environmental Assessment Report. For the Civil Engineering Department, Hong Kong SAR Government.}

^{([11]) ERM - Hong Kong, Ltd (2002) Agreement No CE 44/97 - Environmental Monitoring and Audit for Contaminated Mud Pit IV at East of Sha Chau. Final Report. For the Civil Engineering Department, Hong Kong SAR Government.}

^{([12]) Tam NFY and Wong YS (1997) Ecological Study on Mangrove Stands in Hong Kong: Volume 1. University Press, Hong Kong.}

^{([13]) Tam NFY and Wong YS (1997) Op cit.}

^{([14]) Tam NFY and Wong YS (1997) Op cit.}

^{([15]) ERM - Hong Kong, Ltd (2000) Northshore Lantau Development Feasibility Study. Environmental Impact Assessment. Final Report. For the Civil Engineering Department, Hong Kong SAR Government.}

^{([16]) Chiu HMC and Morton B (1999) The distribution of horseshoe crabs (Tachypleus tridentatus and Carcinoscorpius rotundicauda) in Hong Kong. Asian Marine Biology. 16, 185-196.}

^{([17]) Fong TCW (1999) Tai Ho Bay: breeding and nursery ground of horseshoe crabs. Porcupine! No. 20, November 1999.}

^{([18]) Mott Connell Ltd (2003) Environmental Impact Assessment for Tung Chung - Ngong Ping Cable Car Project. Final Report. For the MTR Corporation.}

^{([19]) Lee SY (1997) Annual cycle of biomass of a threatened population of the intertidal seagrass Zostera japonica. Marine Biology 129: 183 - 193.}

^{([20]) Fong TCW (1998) Distribution of Hong Kong seagrasses. Porcupine! 18, December 1998.}

^{([21]) Fong TCW (1998) Op cit.}

^{([22]) Scott PJB (1984) The Corals of Hong Kong. Hong Kong University Press.}

^{([23]) Lun JCY (2003) Hong Kong. Reef Building Corals Cosmos Books Limited.}

^{([24]) ERM – Hong Kong, Ltd (1995) Proposed Aviation Fuel Receiving Facility at Sha Chau. Environmental Impact Assessment. Prepared for the Provisional Airport Authority.}

^{([25]) Mouchel Asia Ltd (2002) Permanent Aviation Fuel Receiving Facility for Hong Kong International Airport. Environmental Impact Assessment Report. For the Airport Authority Hong Kong.}

^{([26]) ERM-Hong Kong, Ltd (2000) Construction of an International Theme Park in Penny’s Bay of North Lantau together with its Essential Associated Infrastructures – EIA Report. For the Civil Engineering Department, Hong Kong SAR Government.}

^{([27]) Binnie Consultants Limited (1997) Chek Lap Kok Qualitative Survey. Final Report. For the Civil Engineering Department, Hong Kong SAR Government.}

^{([28]) Binnie Consultants Limited (1996) Fill Management Study - Phase IV Investigations and Development of Marine Borrow Areas: Coral Growth at High Island Dam. For the Civil Engineering Department, Hong Kong SAR Government.}

^{([29]) Jefferson TA, Hung SK, Law I, Torey M and Tregenza N (2002) Distribution and abundance of finless porpoises in Hong Kong and adjacent waters of China. Raffles Bulletin of Zoology Supplement 10:43-55.}

^{(2) Jefferson TA (2002) Monitoring of Indo-Pacific Humpback Dolphins (Sousa chinensis) in Hong Kong waters. Final Report. For the Agriculture, Fisheries and Conservation Department, Hong Kong SAR Government.}

^{(3) Jefferson TA (2000) Population biology of the Indo-Pacific Humpback dolphin in Hong Kong waters. Wildlife Monographs 144:1-65.}

^{(4) Jefferson TA and SK Hung (2004) A review of the status of the Indo-Pacific humpback dolphin (Sousa chinensis) in Chinese waters. Aquatic Mammals. 30:149-158}

^{([31]) Jefferson TA (2000) Op cit.}

^{([32]) Ibid.}

^{([33]) Ibid.}

^{([34]) Barros NB, Jefferson TA and ECM Parsons (2004) Feeding habits of Indo-Pacific humpback dolphins (Sousa chinensis) stranded in Hong Kong. Aquatic Mammals. 30:179-188}

^{([35]) Ibid.}

^{([36]) Ibid.}

^{([37]) Data provided by the Agriculture, Fisheries and Conservation Department.}

^{([38]) Data provided by the Agriculture, Fisheries and Conservation Department.}

^{([39]) Data provided by the Agriculture, Fisheries and Conservation Department.}

^{([40]) Data provided by the Agriculture, Fisheries and Conservation Department.}

^{([41]) Jefferson TA (2004) Report to ERM}

^{(1) Agriculture, Fisheries and Conservation Department (1998) Port Survey 1996/1997.}

^{(2) Agriculture, Fisheries and Conservation Department (2002a) Port Survey 2001/2002, web site www.afcd.gov.hk.}

(1) ^{Agriculture, Fisheries and Conservation Department (2002a) Op cit.}

(2) ^{ERM (1998) Fisheries Resources and Fishing Operations in Hong Kong Waters, Final Report, for Agriculture, Fisheries and Conservation Department, March 1998.}

(3) ^{ERM (1998) Op cit.}

(4) ^{Agriculture, Fisheries and Conservation Department (2002b). Web site www.afcd.gov.hk.}

(5) ^{ERM (1998) Op cit.}

(6) ^{Agriculture, Fisheries and Conservation Department (2002a) Op cit.}

(7) ^{Agriculture, Fisheries and Conservation Department (2002a) Op cit.}

^{([44]) Agriculture, Fisheries and Conservation Department (1998) Op cit}

^{([45]) Agriculture, Fisheries and Conservation Department (1998) Op cit.}

^{([46]) Mouchel (2001) Environmental Monitoring and Audit for Contaminated Mud Pit IV at East Sha Chau. First Quarterly Report, May to July 2001. Prepared for CED.}

^{([47]) AFCD (2003) http://www.artificial-reef.net/main2.htm#}

^{([48]) AFCD (2003) Ibid.}

^{([49]) Hong Kong Institute of Education (2002a) Sha Chau and Lung Kwu Chau Marine Park Monitoring Programme,Final Report, September 2002. Submitted to Country & Marine Parks Authority, Agriculture, Fisheries and Conservation Department, Government, Hong Kong SAR Government.}

^{([50]) Hong Kong Institute of Education (2002a) Ibid.}

^{([51]) ERM - Hong Kong, Ltd (1998) Fisheries Resources and Fishing Operations in Hong Kong. Final Report. For the Agriculture, Fisheries and Conservation Department, Hong Kong SAR Government.}

^{([52]) Qian PY, Qiu JW, Kennish R and Reid CA (2003) Recolonization of Benthic Infauna Subsequent to Capping of Contaminated Dredging Material in East Sha Chau, Hong Kong. Estuarine and Coastal Shelf Science 56: 819-831.}