Appendix 3.7

 

Specification for Fishpond Management

 

 

Appendix 3.7

Specification for Fish Pond Management

 

After completion of the works on each pond as described in the HCMP (or in subsequent years after general pond maintenance) a layer of lime and fertilizer (to be specified) will be added to each pond, both at a rate of 3 kg per mu.

 

Each pond will then be refilled to the designated operating levels using at least 75% of the water from fish ponds actively being used for freshwater fish polyculture. These measures are necessary to raise pH and nutrient levels in the pond and provide a 'seed' of phytoplankton, zooplankton and invertebrates which can increase over a 'settling in period'.

 

Water quality will then be tested to ensure that it is within the recommended water quality standards of AFCD for fish culture as indicated in Table 1 below.

 

Table 1

Water Quality Standards for Fish Culture

 

 Parameters

AFCD Standards

Ammonia

< 0.1 mg/L

BOD5

<10 mg/L

Chlorine

<0.1 mg/L

Chlorophyl a

< 1 mg/L

Dissolved oxygen

> 1 mg/L

Oxidized Nitrogen (as nitrogen)

< 5 mg/L

PH

6 - 8.5

Phosphate (as phosphorus)

< 1 mg/L

Salinity

< 2 ppt

Suspended solids

20 mg/L

 

 

In addition to the AFCD standards the water must also meet defined requirements for nutrient levels in each pond.

 

If the water quality does not meet the AFCD Standards and other requirements then the Contractor shall be responsible for altering the chemical composition to meet these standards through partial replacement of the pond water or addition of further lime or fertilizer as necessary.

 

The use of off-site fish pond water sources will be subject to approval of the Site Manager, which will be dependent on the supply having suitable water quality. The Contractor will be responsible for obtaining and testing samples of the proposed water supply for levels of salinity / pH / BOD5 / Ammonia (as nitrogen), oxidised Nitrogen, total phosphate, orthophosphate and Chlorophyll a.

 

Toxic compounds used to kill off pathogens and invertebrates must not be used during the establishment phase or any other stage of the fishpond management.

 

Polyculture fish farming practices will be carried out in each pond according to the following stages and practices.

 

Stage 1:  Stocking

 

Timing, species and fingerling density for stocking will follow similar principles to that utilised in commercial polyculture. However, details of species used, stocking size, stocking density and timing of stocking will be varied to satisfy the requirements of the target bird species. Different stocking regimes may be followed in different ponds to meet the requirements of different target bird species.

 

The Contractor will provide a written list of fish species and the numbers of each to be stocked in each pond for approval by the Site Manager in consultation with a fish culture specialist and, if necessary, an ecologist.

 

Stage 2: Rearing

 

Fish will be fed with traditional organic feeds once per day using traditional manual. Acceptable feed types are corn meal, peanut cake, wheat bran, rice bran, biscuit, bread, brewery waste, noodle, sorghum, soya bean and grass clippings. High protein commercial feeds should not be used. The Contractor should submit details of the type of feed material to be used, for approval as part of the tender submission.

 

The Contractor will provide a written specification for the proposed feeding regime (i.e. stipulating the amount and frequency of application of each feed type to each pond) over the course of each year for approval by the Site Manager in consultation with a fish culture specialist and, if necessary, an appropriately qualified ecologist.

 

During the rearing period the Contractor must monitor the behaviour of the fish, the water quality (according to visual signs and monitoring data) and the amount of feed being consumed. This information may be used to vary the quantities of food provided according to the requirements of the fish. Any variation in the quantities of food applied must be recorded and passed onto the Site Manager at weekly intervals.

 

Organic fertilizers should be added to the pond every two weeks to maintain nutrient levels within target levels to be set by the Site Manager in consultation with a fish culture specialist and, if necessary, an ecologist. Acceptable fertilizers include cattle, pig and poultry manure and peanut cake. Approval must be obtained from the Site Manager before any other types of fertilizer are used. The amount and type of fertilizer applied to each pond must be recorded and passed onto the Site Manager at weekly intervals.

 

The condition of the pond will be monitored by the Contractor through observations of the behaviour and condition of the fish and assessment of water quality data. The Contractor will be responsible for maintaining the water quality within the AFCD Standards and other requirements, if necessary by altering feeding regimes and fertilizer applications.

 

The Contractor will be responsible for supplying, maintaining and operating aeration equipment on each of the ponds under active management. Mechanical aeration should be kept to a minimum and only carried out when dissolved oxygen levels fall unacceptably low.

 

No bird scaring devices, wires, nets or other structures may be used to reduce the numbers of any birds using the ponds or bunds, without the permission of the Site Manager.

 

Stage 3: Drain-down Period

 

Ponds will be drained-down according to a timetable provided in the HCMP according to traditional techniques. Water levels will firstly be lowered to levels set by the Site Manager in consultation with the ecologist. To achieve this water will either be pumped into storage ponds or discharged into the nearest water course, as directed by the Site Manager.

 

During this period monitoring of the  fish, aquatic and benthic invertebrates will be carried out by the Monitoring Contractor.

 

Stage 4: Pond Maintenance and Preparation for Restocking

 

Each pond will be maintained and prepared for restocking according to the requirements and timetable outlined in the HCMP. Where ponds are to be restocked, then a layer of lime and fertilizer will be added to each pond, both at a rate of 3 kg per mu. Each pond will then be refilled to the designated operating levels and the water quality tested to ensure that it is within the recommended water quality standards of AFCD for fish culture as indicated in Table 1 above.

 

Ponds will be drained fully and dried out on a three yearly cycle for pond maintenance requirements. During maintenance, silt layers may need to be scraped from the pond bases by the Contractor and placed on the bunds or removed from site. After completion of the works each pond bund and base must maintain the land form and levels defined.

 

These management procedures may be modified in the future if the modifications can be shown, according to the results of further studies and monitoring of the mitigation area, to be likely to provide further benefits to the target species.

 

Back to Appendix A4.2