Annex II Country Reports (Cont.)

Annex II-13
PAKISTAN

by

Jameel Ahmad, Ministry of Food and Agriculture, Islamabad.

Harvesting a carp culture pond near Lahore in Pakistan

1. SUMMARY

This paper highlights the present status of aquaculture activities in Pakistan, its contribution to inland fish production and the Government's plans for aquaculture development. Since aquaculture development in Pakistan is in its infancy, impacts on the environment and impacts of the environment on aquaculture have not so far been realised. However, laws governing environmental pollution which include aquaculture are being formulated and an awareness is developing of the importance of protecting water bodies from increasing pollution, which may pose serious problems for the development of aquaculture in Pakistan.

2. INTRODUCTION

Although Pakistan has substantial areas of inland waters, because of its location as a drainage basin for the Himalayas, fishing has never been a major economic activity nor have inland fish been a major food source for the inland population. Per capita consumption is about 1.5 kg which is among the lowest in the world. Capture fisheries in inland rivers and lakes has been practised traditionally as a subsistence activity by certain low income groups. Aquaculture is a relatively new activity in Pakistan as it was not practised traditionally, which explains its small contribution to overall fish production. As a result of the absence of a true fisheries statistics collection system, separate statistics for production from aquaculture are not available. However, it is estimated that 20 % of overall inland fish production comes from aquaculture.

There are a number of laws governing efforts to protect air, water, oceans, waste management practices, pesticides and other basic substances, but most of these laws are out-dated and do not comprehensively address the important issues concerning air, water, industrial pollution, deforestation and land degradation. There is a need for a single comprehensive law governing environmental control and protection in Pakistan. The Ministry of Environment and Urban Affairs, Government of Pakistan is presently engaged in formulating a comprehensive law which will address environmental problems in their full compass.

Map of Pakistan

Aquaculture development in Pakistan is still in its infancy and the impact of the external environment on aquaculture and vice versa has not yet been realised. With the rapid pace of aquaculture development in Pakistan, however, it is possible that the country may face the same environmental problems in the future that other South East Asian Countries are now confronted with.

3. STATUS OF AQUACULTURE

Pakistan has relatively limited fisheries resources compared with other Asian countries because of its short coastline, small continental shelf area and arid climate. Total fish production was about 483,000 tonnes in 1990, of which 370,000 tonnes was obtained from marine fisheries and 113,000 tonnes from inland fisheries. The contribution of the fisheries sector to overall Gross Domestic Product is about 1% and about 1% of the country's labour force is engaged in this sector. However, in the coastal areas of Baluchistan province and Karachi, fisheries is a major source of income and employment to the people.

The influence of the Indus River system on the marine fisheries of Sindh coast is substantial, as this river system has historically transported enormous quantities of nutrient and sediments to the continental shelf. With the construction of a number of barrages across the Indus, water has been diverted for power generation and irrigation purposes to the extent that the discharge into the ocean from the Indus has been reduced by almost 90%. Consequently, the delta area has shrunk considerably and the mangrove forest area has been drastically reduced. The reduction in the discharge from the Indus has adversely effected the fisheries of many species of marine fish and shrimp which rely upon the delta for part of their life cycle.

3.1 Shrimp aquaculture

The Government of Pakistan has placed a high priority on the development of shrimp culture in the Indus delta area because of its potential to generate foreign exchange earnings for the country. The Indus delta region has good potential for the aquaculture of marine shrimp. There are about 385,000 ha of inter-tidal lands available which can be converted into shrimp ponds at a very low cost. The Government of Sindh has earmarked 6,400 ha of land for shrimp culture in Thatta district, which will be allocated to private sector. In 1982, the Department of Fisheries (DOF), Government of Sindh started a pilot project for shrimp farming in Thatta District with the financial assistance of the Asian Development Bank. It consists of 56 ha of nursery and grow out ponds with a water pump to lift water to the ponds from the nearby creek. Unfortunately, this project was not successful because of some administrative problems and natural constraints. Some private parties also tried shrimp culture in this area, but were not successful.

The natural constraints to shrimp farming in this area were high salinities and temperatures caused by the reduction in fresh water discharge from the Indus river due to the construction of a number of barrages for irritation and power generation. The salinities in the Indus delta creek reach as high as 45 ppt in the dry season (unsuitable for shrimp culture) which is the direct result of environmental degradation. The other constraint is that of temperature. Most tropical penaeid shrimp species grow best within a temperature range of 28 to 32°C, however, this does not mean that appropriate strategies for shrimp culture cannot be devised. In such areas only one crop of shrimp in summer months can be harvested as against two in other south east Asian countries.

3.2 Status and development of aquaculture in Pakistan

Separate statistics for aquaculture production are not available as a statistical data collection system is non-existent. However, conservative estimates indicate that 20% of inland fish production comes from aquaculture. Table 1 shows the status of aquaculture industry in Pakistan from 1987 to 1990, based on the published statistics of the Marine Fisheries Department in Karachi.

Table 1. Status of aquaculture in Pakistan.

(nd = no data)
¹ (1 US $ = 30.8 Rs)

Pakistan has extensive inland and coastal water resources comprising the Indus river and its tributaries; vast canal systems; natural lakes; the Indus delta; and man-made reservoirs. Three provinces of Sindh, Punjab and North West Frontier Province (NWFP) possess considerable potential for the development of inland fisheries and aquaculture. Inland and coastal water resources are given in Table 2.

Table 2. Inland and coastal water resources.

3.3 Existing aquaculture practices in Pakistan

The main aquaculture system which has been successfully developed in Pakistan is carp pond culture. It is essentially extensive culture. Three indigenous carp species and three exotic species are being cultured successfully. These are: Labeo rohita; Cirrhinus mrigala; Catla catla; Cyprinus carpio (common carp); Hypophthalmichthys molitrix; and Ctenopharyngodon idella (grass carp). In addition, trout are being cultured in cold water, mainly in NWFP province. Two species of trout namely; rainbow trout and brown trout are cultured.

Shrimp culture in the Indus delta region has been tried on an experimental basis, but did not succeed for the reasons already explained. No efforts have yet been made to culture marine finfish in coastal waters, although great potential exists for finfish culture in Indus delta region.

3.4 Supply of inputs to the aquaculture industry

Most carp species (both indigenous and exotic) are being cultured in Pakistan using traditional pond culture methods with very few inputs. Manuring is carried out with cow dung and stocking is done by the seed supplied from government hatcheries established by the Departments of Fisheries. Some private hatcheries have also been established in the province of Punjab. There are 14 hatcheries in total in the country with a total fry production of 48.5 million. Most freshwater fish are grown under polyculture with a suitable combination of different species. The fish stocked are plankton feeders, column feeders and bottom feeders.

Shrimp culture of the tiger prawn (Penaeus monodon) and banana prawn (P. merguensis) has been tried in Indus delta region with little success, the fry were imported mainly from Malaysia. The lack of a hatchery for tiger or banana prawn is one of the major constraints in the development of shrimp culture. Also there is not enough natural seed available due to environmental degradation.

3.5 Present production

The statistics published by Marine Fisheries Department show that total finfish production from inland waters was 113,158 tonnes in 1990, of which 24,200 tonnes. was contributed by aquaculture. In 1989, 21,000 tonnes was produced from aquaculture, representing an increase of 15%. Some 80 tonnes was trout from the NWFP and the rest was carp production.

3.6 Legal framework

All four provinces of Pakistan have their own fisheries by-laws to regulate fisheries management, such as:

1. The West Pakistan Fisheries Ordinance, 1961;

2. Baluchistan Sea Fisheries Ordinance, 1971;

3. Sindh Fisheries Ordinance, 1971;

4. The NWFP Fisheries Rules, 1976.

3.6.1 Access to aquaculture operations

Definition of aquaculture
There is no legislation governing aquaculture, and therefore no legal definition of aquaculture in Pakistan.

Aquaculture laws and regulations
There are currently no specific laws relating to aquaculture.

Consent/authorisation mechanism
There is no requirement for aquaculture farms to register or apply for an operating licence.

Special consent system
There are no legal codes of practice for the utilisation of rivers, lakes, mangroves or coastal areas for aquaculture. However, site selection criteria that include environmental considerations, are available for inland finfish farming.

3.6.2 Environmental management of aquaculture

Water quality and water pollution control
Provincial fisheries departments monitor general water quality parameters of the aquatic environment in both inland and coastal areas. However, there are no legal criteria for acceptable water quality conditions in aquaculture farms or for the effluents discharged from farms. There are specific laws and regulations to check industrial waste disposal into inland water ways, however, there are inadequate resources to monitor effluent discharges.

Environmental Impact Assessment
No formal Environmental Impact Assessment (EIA) is undertaken prior to the development of aquaculture farms.

Control of the movement of fish
Imports of live fish, including ornamentals, require a health certificate issued by the exporting country, and all newly introduced species require a period of quarantine and a certificate from the Animal Quarantine Department. In this respect, there are no control on inter-provincial movements of fish.

Control of toxic or hazardous substances, or pharmaceutical preparations
There are presently no regulations on the use of chemotherapeutants on aquaculture farms in Pakistan.

Control of pesticides
There are no controls on the use of any biocides on aquafarms.

“Protected areas”
There are no protected areas declared and no such rules governing them.

Protection of indigenous species
There is a requirement in the public fisheries department to place introduced species in quarantine to reduce the health risk to indigenous fish. It is covered by the Animal Quarantine Act.

Fish health
Imports of live fish require a health certificate issued by the exporting country and some shipments are kept under quarantine, governed by the Animal Quarantine Act.

Product quality control
Fish products from all aquaculture farms under the management of the Department of Fisheries are required to meet certain quality standards. Criteria governing the weight, size, freshness and hygiene status of the products are carefully monitored to protect the consumer and reduce the risks to public health. Health Departments and Agriculture and Livestock Marketing Advisors are responsible for enforcing these standards. In addition, the Pakistan Standard Institute has established new standards for the export quality of dried and dried and salted fish.

3.7 Pakistan Government's policy towards aquaculture

The Government of Pakistan is now giving emphasis to the development of the fisheries sector in the country and Rs. 1500 million was allocated to the fisheries sector in the 7th Plan period. Priority is being given to aquaculture development in the country. Aquaculture Development Projects are underway with a total cost of $ 19.5 million in the provinces of Sindh, Punjab and NWFP. The implementation of these projects has boosted fish production from aquaculture in the country. The development plan under this project aims to:

1. Upgrade extension services;

2. Establish model demonstration farms;

3. Improve facilities for production of quality seed;

4. Establish training centre for farmers.

In this context, much attention has been given to the creation of facilities, such as fish hatcheries, for the large-scale production of quality fish seed through induced breeding of fish, the accelerated development of technology for aquaculture practices and the mobilisation of the private sector for undertaking fish culture on a commercial scale.

4. INTERACTIONS BETWEEN AQUACULTURE AND THE ENVIRONMENT

Pakistan has substantial aquatic resources and, although fisheries contributes relatively little (1.0%) to overall GDP, it is of recognised economic importance as it provides products for exports, a source of employment and a substantial supply of animal protein. As production from inland fisheries appears to be declining due to environmental change and over fishing, the aquaculture industry has been accorded particular priority in the national development plan to increase fish production and utilise wastelands. It is estimated that over 3 million ha of waterlogged land could be developed for fish farming and about 15,000 ha of marginally productive agricultural land has potential for conversion into fish ponds. Aquaculture is currently at an early stage of development and is mainly practised at an extensive level. However, a rapid growth in the industry is envisaged and a gradual shift towards semi-intensive culture systems is already evident. Marine finfish production comes almost exclusively from capture fisheries, but mariculture potential along the Indus delta needs to be exploited to augment production. The development of shrimp aquaculture has also been attached high priority by the Government of Pakistan.

There is very little information on the relationships between aquaculture and the environment in Pakistan but presently these are not considered significant. However, future development of the industry could result in detrimental impacts to the environment and plans are being made to develop strategies to avoid future problems developing.

4.1 Impacts of external environment on aquaculture production

4.1.1 Inland aquaculture

Physical factors
Land erosion, sedimentation, flooding and other detrimental water movements have had localised effects on inland fisheries and aquaculture and these may become more significant in the future. Irrigation projects, along with flood control measures, are increasingly changing the course of the Indus river resulting in the destruction of fish breeding grounds and declining fish catches. The resulting siltation may also have significant impacts on aquaculture.

Toxic industrial wastes
Industrial pollution can have occasional localised impacts on inland aquaculture, and these are expected to intensify in the future. These problems are dealt with in legislation, but there are insufficient resources to enforce the regulations.

There have been several studies documenting the effects of industrial waste discharges on fisheries. For example, the Deg Nallah, a flood drainage channel near Lahore has suffered severe impacts of such pollution. Over twenty years ago, it had a rich fish fauna sustaining a fishery of 10 t/year but following the development of a large industrial zone, untreated waste water was drained into the Nallah, which is now devoid of fish. The effects continue in the River Ravi which receives polluted water from the Deg Nallah.

Human and agricultural wastes
Many aquatic systems are becoming polluted from the continuous dumping of untreated municipal wastes. There have been cases where the fish fauna has been completely wiped out as a result. Studies on the Lei stream have indicated that it supports a large fish production in the vicinity of Islamabad (which has a well established sewage disposal system) but after having received untreated industrial waste and raw sewage from the old city of Rawalpindi, it is now devoid of fish life. Such pollution of aquatic resources may exert severe constraints on aquaculture development in Pakistan.

The release of fertilisers from nearby agriculture farms have caused nutrient enrichment and resulted in eutrophication, low dissolved oxygen levels, microbial contamination and phytoplankton blooms that affect aquaculture. The uncontrolled use of pesticides in agriculture may have detrimental effects to aquaculture. Mortalities from dissolved oxygen deficiency have been occasionally reported following die-offs of algal blooms. Periodic die-offs of blue-green algae have also been noted as a cause of mortality.

Petrochemical discharges
No problems of petrochemical discharges have been recorded affecting aquaculture.

Radioactive contamination
There are no dangers of radioactive contamination.

4.1.2 Coastal aquaculture

Physical factors
The removal of mangroves is of concern to coastal aquaculture. Salinisation of Pakistani coastal waters and creeks is occurring as a result of the retreat of the Indus delta and the drastic reduction in its volume because of agricultural abstraction. High turbidity in coastal waters, combined with high salinities, may pose a threat to marine resources and create conditions unsuitable for the culture of most species of brackish water fish.

Toxic industrial wastes
There is growing concern in Pakistan regarding marine pollution from industrial waste. Karachi on the northern border of the Arabian Sea, is the largest industrial and most densely populated coastal city and is expanding at an extraordinary rate. Large amounts of untreated industrial and domestic wastes are being discharged through the Lyari River into Karachi Harbour and subsequently into the sea. BOD values of 237 tonnes/day were obtained from effluent, 85% of which is from industrial wastes.

Human and agricultural wastes The release of pesticides and fertilisers from agricultural activities may have some impact on fish farms. Whereas pollution along the coast of Baluchistan is negligible due to the thin coastal population and lack of industry, shellfish fisheries in Sind province have suffered from pollution-related mortalities. Aquaculture development in this area would suffer similar effects.

In 1990, a toxic red tide occurred off the coast of Sind province. It caused serious damage to mollusc and finfish fisheries, but this has not been quantified. Plans have been made to develop a strategy to deal with similar incidents in the future.

Petrochemical discharges
Oil spills have been recorded in coastal areas and may have increasing impacts on aquaculture in the future. There is also significant localised pollution from boats such as the 2,000 or more mechanised fishing boats that operate in Karachi Harbour.

Radioactive contamination
There are no dangers of radioactive contamination.

4.2 Contamination of aquaculture products

No reports of contamination of aquaculture products have been received but as the industry expands, measures should be taken to reduce the public health risk. Organic manures are used to fertilise pond waters but no significant outbreaks of human bacterial infection have been reported as a result of consuming fish from these ponds. Fish can be intermediate hosts for a number of metazoan parasites that can infect man but no such relationship has so far been established in Pakistan. Industrial pollutants, such as metals, are at present of minor health significance in Pakistan, but with increasing industrialisation they may become a problem. The increasing use of insecticides in agriculture and their concentration in fish may constitute a public health hazard. Spoilage of fish products is a problem in Pakistan and a lack of awareness and limited facilities for adequate handling, storage and distribution of fishery products, compounds the problem.

4.3 Impacts of aquaculture on the environment

4.3.1 Inland aquaculture

Aquaculture practices have not yet created any noteworthy adverse environmental impacts in Pakistan.

Physical factors
The limited number of finfish ponds presently pose little threat to the environment. Algal blooms have increased in a few cases and there have been problems of increased alkalinity. The more intensive ponds and hatcheries have also resulted in salinisation, acidification and some pollution from chemotherapeutants. Although oxygen depletion may occur within pond systems, it is not a problem in the external environment. Deforestation for the construction of further ponds may cause land subsidence problems in the future and the related problems of sedimentation and reduced water flow.

Chemical factors
KMnO₄, malachite green and Bytax are the chemotherapeutants most commonly used in aquaculture, but they are not considered to have a significant impact on the environment. They are not used in large quantities and have not been reported to have caused a public health risk.

Biological factors
Disease outbreaks in farm stock may have affected wild fish stocks, but this is not expected to have serious impacts in the future as management practices and disease controls improve. The impact of aquaculture farms on bird populations have also been significant. Other impacts of aquaculture on wild fish stocks will become more significant as the industry expands.

Social conflicts and aquaculture
As aquaculture is still not widely practised, no competition with other users of aquatic resources has been reported. Aquaculture activities with discharges into reservoirs from which water is used for domestic consumption are regulated and fertilisation for increasing fish productivity is not allowed.

4.3.2 Coastal aquaculture

Coastal aquaculture has not yet had any impacts on natural resources or resulted in conflict with other aquatic resources users. However, it is envisaged that the development of shrimp and finfish ponds will, in the future, result in the removal of mangrove areas, coastal erosion, reduced water flow, sedimentation, eutrophication and pollution from chemotherapeutants.

Mangrove forest in the Sind delta is particularly under threat from human interference. Clearing of areas for pond construction is at present minimal, and most of the damage to the ecosystem is from wood cutting, reduced water supply and industrial waste.

5. PRIORITIES FOR DEALING WITH ENVIRONMENTAL PROBLEMS

5.1 Prevention and cure of the detrimental effects to aquaculture of man-made changes to the environment

At present, no impacts of the external environment are considered significant enough to constrain aquaculture development. The major constraints to aquaculture development are a lack of information about pond stocking and management techniques, as presently pond yields are too low to provide sufficient financial returns. Improved training and extension facilities are needed to upgrade knowledge on all aspects of fish husbandry.

Adequate conservation methods should be adopted to check the hazards of pollution and over fishing of undersized fish. Fines prescribed under existing fisheries laws are not effective, these should be raised and greater legal powers entrusted to fisheries officers so that conservation measures can be enforced more effectively.

Annex II-14
PHILIPPINES

by

Nelson. A. Lopez, Bureau of Fisheries and Aquatic Resources, Manila.

Pen cage culture on Laguna de Bay. The expansion of pen culture has caused conflicts with other users of this large inland lake.

1. SUMMARY

This study is an initial effort by the Philippines Government to review and document the present and existing status of the aquaculture industry in the Philippines, focusing primarily on environmental issues. The project aims to draw preliminary sectoral interventions from policy makers, biologists, environmentalists, social scientists, economists and fish farmers who are directly involved and responsible for the subject. An assessment and evaluation of the actual impact of the environment on aquaculture, and vice versa, are presented. The focus of the report is an in-depth study of two specific priority commodity species and farming systems. A review of related legislation was also used as a baseline from which legal and administrative frameworks on environmental management could be formulated for future aquaculture development. The study concluded with a national seminar-workshop attended by sectoral representatives with multi-disciplinary involvement on the subject. Key researchable areas and policy directions were identified as being in need of a holistic approach with participatory interventions.

2. INTRODUCTION

The need for research, training and information exchange on matters related to aquaculture and the environment is one of the most significant issues presently faced by the aquaculture sector in the Philippines today. The stages vary from less serious threats to the industry, to a potential total economic loss from environmental impacts such as health hazards, disease outbreaks and the degradation of resources due to industrial pollution and improper resource utilisation. The scope of the in-depth study covers a multi-disciplinary review of the culture of marine shrimps in brackishwater ponds and tilapia farming in freshwater pen and cages. The main report provides a comprehensive review of the interactions between aquaculture and the environment in the Philippines.

Map of the Philippines.

3. STATUS OF AQUACULTURE

3.1 Total aquaculture production (Table 1)

Table 1. Total aquaculture production in the Philippines, 1987–1991

3.2 Inland and coastal resources (Table 2)

Table 2. Inland and coastal resources of the Philippines (Source: BFAR, 1990. Philippine Fisheries Profile and National Accounts of the Philippines, 1992).

3.3 Aquaculture commodity species by culture system and types of supply inputs

An area of 12,644 ha is occupied by inland finfish cage or pen farms and 14,531 ha by finfish pond farms in the Philippines. The species cultured and the productivity of these systems, as well as coastal systems, are detailed in Table 3. Coastal finfish pond farms cover 222,907 ha in the Philippines, 20,000 ha of which was occupied by shrimps ponds in 1987. Mollusc culture covers an area of 1,068 ha and seaweed culture occupies 7,330 ha of coastal area (including ponds).

Table 3. Species cultured, culture systems, inputs and production of aquaculture in the Philippines.

Key: TF = Trash Fish;
NF = Natural Food;
BC = Bread crumbs;
CP = Commercial pellets;
d = domestic;
e = export.

3.4 Supply of inputs

Inland finfish culture primarily depends on natural food production in lakes and rivers, but is often supplemented with rice bran, flake and, more recently, formulated feeds (Table 3). Of the coastal cultured finfish, grouper (Epinephelus sp.) seed is exclusively collected from the wild, but most other species are also artificially produced. Hatchery production of seabass (Lates calcarifer) fry has already been established. Trash fish is used as feed in grouper and seabass culture, algae are fed to rabbitfish (Siganus guttatus), and the main input in milkfish (Chanos chanos) farming is fertiliser to enhance phytoplankton growth.

The aquaculture industry is now centred on increasingly intensive monoculture of shrimps using hatchery reared post-larvae and feeding with formulated dry pellets. However, traditional culture using only natural feed or occasional supplemental feeding with trash fish, bivalves, snails or rice bran is still practised, often in polyculture with milkfish. The farming of oyster (Crassostrea sp.) and green mussels (Perna viridis) in the Philippines relies on the collection of wild spatfalls and the available food nutrients in the water resources. Coastal seaweeds are naturally propagated from wild sources through natural growth of fronds and sporophytes.

3.5 Legal framework

3.5.1 Access to aquaculture operations

Definition of aquaculture
Aquaculture applies to all farming practices of finfish, crustaceans, molluscs and seaweeds in the Philippines. The term “aquaculture”, however, has not been defined in any relevant legislation, except for the structural description of some traditional culture systems as cited in P.D. 704 (Chapter I, Sec.3) such as family size fish pond, fish pen and a fully developed fish pond.

Aquaculture laws and regulations
A series of laws have been enacted for the aquaculture and fisheries industry, which are related to conservation of resources and the environment. There are, however, numerous local regulations promulgated by some municipal governments which are also directed to utilisation of resources and the environment for aquaculture purposes. A list of relevant rules and regulations are shown below:

Consent authorisation mechanism
All aquaculture farms in the Philippines require registration. The roles of the various agencies in the control of aquaculture farms are also shown below:

Institutional framework regulating aquaculture development in the Philippines

A. Government planning, licensing and monitoring of aquaculture related operations

B. Governing environmental issues relating to aquaculture

Special consent system
There are codes of practice for the utilisation of lakes, rivers and coastal areas (including mangroves) for aquaculture purposes as provided for in Section 29 and 30 of PD 704, respectively. These codes of practice concern the granting of fisheries privileges to the highest qualified bidder in the operation of corrals, oyster beds and fry gathering zones and the approval of the Secretary, upon the recommendation of the BFAR Director, for municipal concessions and leases concerning fishing or fisheries in streams, lakes, rivers, inland and/or municipal water. It is known, however, that the DENR have also imposed a set of rules and regulations governing utilisation of the same resources, particularly of mangrove areas under its jurisdiction. Furthermore, with the adoption of the local government code, all previous rules and regulations consistent with the utilisation of local resources may have already been superseded by this new legislation.

3.5.2 Environmental management of aquaculture

Water quality, pollution control and monitoring
Water quality criteria exist for each individual cultured commodity group, these include physico-chemical parameters and biological productivity of the water. There are, however, no standard requirements for the treatment of effluents from land-based aquaculture farms. Monitoring of aquaculture effluent quality is among the designated activities of the NPCC and EMB, although it is seldom carried out. There is a need to establish standards for effluent quality that apply to all farming systems, not only aquaculture. A law already exists (PD 600 and 979 as amended) known as the Marine Pollution Decree of 1976 which governs the prevention and control of pollution in the marine environment.

Environmental Impact Assessment
FAO 123 series of 1978 is the only EIA related law requiring an Initial Environmental Examination for all aquaculture development related projects.

Control of the movement of fish
Fish quarantine and certification regulations are incorporated into the Fisheries Administrative Order No. 135, series of 1981.

Required procedures for importing live fish to the Philippines (after Natividad, 1987).

1. Consignee applies to the Bureau of Fisheries and Aquatic Resources (BFAR) for a permit.

2. If successful the consignee notifies the exporter who ships the live fish.

3. On arrival, the shipment must obtain Administrative Clearance from BFAR, Fisheries Quarantine Station and the Bureau of Customs. The shipment is visually inspected and the contents verified.

4. Depending on the findings, the shipment is released, put on hold or confiscated.

5. Illegally imported, infected or diseased fish are put on hold or confiscated. Confiscated fish are sent to BFAR for destruction or research.

6. Released fish go to the consignee.

Required procedures for exporting live fish from the Philippines (after Natividad, 1987).

1. The consignor applies to the BFAR for a commercial permit or commodity clearance.

2. If successful, the consignor notifies the BFAR of the date, time and flight number of the carrier.

3. Administrative clearance is required by the BFAR and the Bureau of Customs, who visually inspect the fish and verify the contents of the shipment.

4. Fish shipments may be released or put on hold depending on the findings of the Quarantine Officer.

5. Infected/diseased fish are not allowed to leave the country and confiscated fish go to BFAR for destruction or research.

6. Healthy fish are allowed to be shipped to their country of destination.

With the imposition of Executive Order (EO) No. 8 and Central Bank Circular No. 1356, however, the importation of live fish, crustaceans and mollusc was liberated, superseding the provisions of FAO 135 of 1981. Hence, the environment and the local fisheries were exto the dangers of unregulated introduction of imported species. The BFAR through the DA Secretary has requested NEDA the re-imposition of prior approval by BFAR for the importation of fisheries commodities, and the result is a standstill.

Control of toxic or hazardous substances, or pharmaceutical preparations
The Department of Agriculture issued Administrative Order No. 60, 1990 to ban the use of chloramphenicol in animals destined for human consumption. There is a need for the implementation of further rules and regulations for the registration and labelling of veterinary drugs, including those that are used in aquaculture.

Control of pesticides
The Fertilisers and Pesticides Authority (FPA) is the duly mandated agency under the Department of Agriculture who have the task of regulating and formulating policy regarding the use of chemicals in the agro-fisheries industry. The latest aquaculture related policy imposed by the agency is DA Pesticide Circular No. 1, series of 1990, calling for the immediate suspension of importation, sale and use of organotin compounds.

“Protected areas”
Section 73-73b of Act 4003, the first and most comprehensive fisheries law enacted in 1932, defined reserve fisheries as “designated areas in Philippine waters for the exclusive use of Government or inhabitants thereof, or for the culture of fish and other aquatic animals for education and scientific purposes”. These were updated by the Water Code and Watershed Reservation proclamations under PD 1067 and 1515 and subsequent Presidential Proclamations allocating parcels of land for fishpond estates. Mangrove swamp forest reserves and municipal waters for pearl culture, seaweed farms and oyster beds. These laws, however, tend to be obsolete and superseded by the local government code transferring all the resource jurisdiction to the municipalities.

Fish health
Fish health management in the country is still being acted upon by the established fish health units of the Bureau of Fisheries and the SEAFDEC-AQD in terms of laboratory experiments, control and policy recommendations. There are no rules or regulations governing fish health that are legally enacted at the moment.

Product quality control
There are standards for aquaculture product quality based on freshness and disease-free status for shrimp and finfish; freshness and toxin-free status for shellfish; and freshness and moisture, alginate and carrageenin content of seaweeds. The DA/BFAR, DTI, DOST/NIST and DOH/BFDA are responsible for enforcing these standards. However, these standards were not legally sanctioned by national legislation and are only imposed on companies or operators that are mostly engaged in exports. There is a need for the implementation of standards and legal requirements for the monitoring of product quality, whether it be for export or for local consumption.

Compliance control and related problems and difficulties
Several constraints including the lack of technical, financial and manpower resources hinder compliance control of the above legislation. A continuous monitoring programme of the aquatic environment including aquaculture farms and their effluents was to be carried out by an inter-agency joint team, but due to the constraints mentioned above, this vital task has not been adequately undertaken.

3.6 Government policy

National environmental policy, planning and regulation is under the mandate of the Environmental Management Bureau of the Department of Environment and Natural Resources, but this agency is not involved in the planning of aquaculture farms. As a matter of policy, it is the Bureau of Fisheries and Aquatic Resources of the Department of Agriculture that is involved in site selection, planning and registration and licensing of aquaculture farms.

Presently there is no national committee with the responsibility for considering environmental issues of relevance to aquaculture. The implementation of the CRM and the Aquaculture Component Project under the FSP, funded through a five year loan from the Asian Development Bank, is an initial effort by the government wherein environmental issues of relevance to aquaculture development are to be considered as priority.

National Plan

There are existing national aquaculture related research and development plans which are prepared annually or included in 5-year plans. These are prepared on the basis of the relevant agency and depend upon their target priorities and functional mandates. These plans are often integrated with those of other collaborating agencies, but there is no existing body that integrates an overall environmental plan. Moreover, these plans are mostly centred on research and production aspects. Recently, however, under the FSP-CRM scheme, the coastal plan for aquaculture and the environment is being integrated under an overall coastal management plan. The BFAR on the other hand is currently implementing the five-year Medium Term Fisheries Development and Management Plan covering aquaculture projects as a matter of policy in the government.

4. INTERACTIONS BETWEEN AQUACULTURE AND THE ENVIRONMENT

The Philippines abounds with potential sites for aquaculture: extensive inland freshwater areas; wide areas of protected coastline; and unexploited offshore waters. The levelling off and even decline in production from capture fisheries has accelerated development in the aquaculture industry. However, growth of this sector is constrained by various environmental factors, most of which can be attributed to human intervention. The impact of these environmental factors are becoming critical both in terms of threats to aquaculture production levels and destruction of the ecology of the environment from which the culture species have been nurtured.

4.1 Impacts of external environment on aquaculture production

4.1.1 Inland aquaculture

Physical factors
Aquaculture in landlocked lakes like Laguna de Bay suffers from several physical problems and the indications are that these will become more severe in the future. Problems of flooding, land erosion and sedimentation have been exacerbated by legal and illegal human activities, mainly mining and the deforestation of large tracts of land. Widespread damage has been caused by natural disasters such as the frequent typhoons and the recent volcanic eruptions of Mt. Pinatubo. Some of the major aquaculture producing provinces (i.e. Pampanga, Tarlac, Zambales, Bulacan and Bataan) were affected as a result of the Mt. Pinatubo eruptions. Some 6,942 ha of fishponds were damaged being partly or totally covered by ashfall, lahar flow or volcanic debris. An estimated loss of stock and facilities amounted to 273.2 million Pesos¹.

Toxic industrial wastes
The discharge of toxic industrial waste into Laguna de Bay is considered a severe problem with widespread consequences for inland aquaculture and fishing activities. There are large factories and known chemical processing plants abounding on the lakeshore areas where mine tailing disposal and waste treatment requirements are not enforced, although there are environmental laws imposed by the government.

Human and agricultural wastes
The most significant effects from the discharge of domestic and agricultural wastes are seen in Metro Manila and Central Luzon areas where coastal and inland aquaculture is widely practised. It is regarded as a major cause of eutrophication, phytoplankton blooms and oxygen depletion, as seen in Laguna Lake. There is, however, no specific information as to the adverse effects of pollution on the aquaculture industry. Research is presently being conducted by selected institutions as to the effects of human and agricultural waste on cultured species. Urbanisation has led to an increase in discharges of household effluents to major inland river tributaries affecting the farm systems in paddy culture, cages and ponds. Most often, planning restrictions on sanitation, sewage and waste disposal are not strictly followed.

Phytoplankton blooms
Following prolonged hot, dry seasons and during the onset of the rainy season, blooms of blue-green algae have occurred in Laguna Lake affecting cultured and wild finfish. These are thought to be blooms of Microcystis sp., but this is subject to verification as there has been a lack of research work undertaken. Fish kills occur due to the anoxic conditions caused by the blooms, but there are no specific records of economic losses and no relationship between disease and the blooms has been established. This has, however, greatly affected the market price and consumption of the cultured species due to the unacceptable taste and pungent smell of the fish.

Petrochemical discharges
Problems of petrochemical spills that directly affect aquaculture are not common in inland water bodies, with the possible exception of Laguna Lake. Pasig River, for example, which has a tidal influence in Laguna Lake is also bounded by some known major petrochemical depots. The possibility of accidental spills during loading and shipments cannot be discounted.

Radioactive contamination
There are no records of radioactive contamination affecting aquaculture.

4.1.2 Coastal aquaculture

Physical factors
A severe, perennial problem is the occurrence of typhoons which affect most of the provinces in Luzon and Visayan regions almost every year. Fish farmers have adapted the timing of aquaculture activities to avoid major economic losses. Other factors such as flooding, siltation/sedimentation, land erosion, land reclamation, mining, vast deforestation and pollution with solid waste matter and garbage are major causes of resource degradation in the aquaculture industry and result in severe losses in both production and investment.

¹ 1 US $ = 24.5 Pesos)

The effect of lahar flow (volcanic debris) is emphasised here following the devastation brought about by the eruption of Mr. Pinatubo which displaced a total of 824 brackishwater fishpond operators and caused a total of 273.2 million Pesos worth of damage to stocks and facilities.

Toxic-industrial wastes
The effects of toxic industrial waste on aquaculture are severe in several areas of the Philippines. Manila Bay is the most urbanised bay area in the Philippines and where coastal aquaculture is most affected. Toxic wastes and industrial residues are drained into this catch basin via the Pasig river. Studies on tolerable toxic levels and close monitoring of the bay are required to determine the effects on aquatic animal populations.

Human and agricultural wastes
Discharge of domestic wastes into Manila Bay, and other areas near urban centres, often results in severe problems of eutrophication and phytoplankton blooms. It is thought that these problems will continue to intensify in the future. The effect of agricultural wastes on coastal aquaculture is not considered severe compared with other factors, although occasional incidents are reported in the provinces of Bulacan, Pampanga and Bataan which are bounded by huge areas of agricultural land.

Phytoplankton blooms
The most critical and only known phytoplankton bloom affecting coastal aquaculture in the Philippines is the perennial occurrence of the red tide blooms in particular areas of the country. These blooms are caused by the toxic effect of a dinoflagellate species known as Pyrodinium bahamense. Table 4 summarises records of incidents attributed to the red tide and their impact on the economy.

Table 4. Summary of red tide incidents in the Philippines.

Petrochemical discharges
No major incidents have been reported regarding this aspect but constant monitoring activities are required, especially in areas where petrochemical refineries are situated.

Radioactive contamination
There are no records of radioactive contamination affecting aquaculture to date.

4.2 Contamination of aquaculture products

4.2.1 Inland aquaculture

Mercury contamination has been recorded in some cultured freshwater finfish, shrimp and mollusc products. Herbicide residues and bacterial contamination has also occurred in cultured finfish products from some areas.

4.2.2 Coastal aquaculture

Finfish
Some pelagic species along Manila Bay had been banned in the market due to fears of possible PSP contamination caused by red tides, but this has not affected cultured finfish. Other possible contaminants are mercury and lead in fish farm areas affected by mine tailing practices and the illegal dumping of industrial wastes. Antibiotic and herbicide residues and contamination with phycotoxins and Vibrio sp. are also occasionally significant in finfish products.

Crustacea
Microbial contamination with Vibrio sp. is widespread in shrimp culture; Salmonella sp., viral diseases such as MBV, and phycotoxin-producing fungi are also occasionally significant. Salmonella sp. is believed to contaminate shrimps because of poor practices in handling and processing. The use of chicken manure to fertilise brackishwater ponds is a source of Salmonella sp. contamination and should be avoided (Llobrera 1987). Resistance to antibiotic treatment has also been reported lately, particularly in the use of oxytetracycline for shrimp diseases. This results in the overuse of drugs, and the detection of residues in shrimp products has been blamed for the sudden slump of the Japanese shrimp market. Low levels of mercury have also been recorded in cultured brackishwater crustaceans.

Mollusc
Paralytic shellfish poisoning (PSP) due to red tides and coliform bacteria infections are the most significant dangers to public health from consuming cultured molluscs. Many cases of PSP caused by the ingestion of shellfish contamination with Pyrodinium bahamense var. compressum from Manila Bay have been reported by Estudillo and Gonzales (1984) and Gacutan et al (1985). Mercury residues and phycotoxins have also been recorded.

Seaweed
Mercuric and lead contamination are most likely to occur in areas where mine tailing is prevalent such as in some areas of Mindanao. “Ice-ice” disease is also known to occur in Eucheuma sp.

4.3 Impacts of aquaculture on the environment

4.3.1 Inland aquaculture

The most common forms of inland aquaculture in the Philippines are semi-intensive or extensive finfish cage, pen and pond culture in the Central Luzon and Laguna areas. They also have the greatest effects on the external environment.

Physical factors
The release of excreta, metabolites and excess feeds from cage farms in particular, has caused siltation of the major lakes. The build up of sediment along with the overcrowding of fish pens and cages has resulted in reduced water flow. Sludge formation as a result of discharges from these farms also increases the level of eutrophication, the number of algal blooms increase and dissolved oxygen levels in the lakes decrease. The release of pond effluents have similar effects on the receiving waters. Pesticides and chemotherapeutants may also be discharged in the effluent. Deforestation of areas for the construction of pond farms has also a significant effect on inland aquaculture.

Chemical factors
Chemicals which are widely used in inland and/or coastal aquaculture in the Philippines are shown in Table 5.

Table 5. Chemicals used in inland and/or coastal aquaculture in the Philippines (after Baticados and Paclibare, 1991).

Drugs were massively overused in shrimp culture facilities in the early 1980s despite warnings by fish pathologists and extension specialists of the consequences. The prevalence of infectious disease suggested that the drugs or dosages given were not effective, or that the pathogens had developed resistance to the drugs. Chemicals, which were tested to control luminous vibriosis, have instead caused mortalities, incomplete moulting and morphological deformities in the shrimp. Overdosing of some known drugs is often detrimental to the stock being treated due to the toxicity of these chemicals. Aquaculturists now believe that excessive use of antibiotics may cause sterility in fish broodstock.

The use of chemotherapeutants also impact on human health, both in terms of public consumption of aquaculture products and the risks to farm workers applying the chemicals. Chloramphenicol has erythrocyte-destroying effects on humans and may be harmful to users who come into contact with it. Furazolidone has been implicated as a potential carcinogen. Malachite green is reported to have potentially carcinogenic and teratogenic properties. Despite the prohibitively high cost of antibiotics, chemotherapy is massively overused for aquaculture purposes.

Interactions between aquaculture and native species
Stocks of some wild fish species are known to be decreasing, and this may be partly due to the capture of wild seed for culture purposes. The introduction of pathogens through the importation of live fish has demonstrated the need for an effective quarantine and certification system.

It has been reported, for example, that exotic parasites have entered the Philippines through the importation of tilapias (Bondad-Reantaso and Arthur, 1990). The transfer of disease between wild and cultured stock has also caused damaging losses, particularly in the case of epizootic ulcerative syndrome (EUS).

Social conflicts and aquaculture
Finfish pond farms in Central Luzon and the Laguna provinces compete with other users of freshwater resources including construction works (e.g. irrigation systems and hydroelectric dams), the agricultural sector, land based industry and other aquafarmers. Fish farmers also compete amongst themselves for the main inputs such as seed, feed and fertiliser.

Finfish cage farms in Laguna Lake cause conflicts as they present navigational hazards to shipping and restrict access to fishing grounds by artisanal fishermen. There is also a degree of competition between aquafarmers in Laguna Lake for access to sites.

4.3.2 Coastal aquaculture-Crustacea

Physical factors
Intensive finfish and shrimp ponds, cages and hatcheries have severe effects on the environment in the Philippines. The release of effluent containing organic matter, toxic metabolites, micro-organisms, pesticides and drugs from these farms result in significant pollution problems and human health risks. Problems of eutrophication, oxygen deficiency and algal blooms are particularly severe. Shrimp and finfish ponds and hatcheries are also blamed for the salinisation of water resources.

Deforestation of mangrove areas and the construction of pond farms has resulted in a degree of coastal erosion and land subsidence which causes further problems of sedimentation and reduced water flow. The proliferation of cage farms and the sediment they produce has also reduced water flows in some areas.

Chemical factors
See inland aquaculture section.

Impacts of coastal aquaculture on mangrove
Since most of the Philippines brackishwater ponds were constructed from mangrove swamps, deforestation of mangroves and swamplands by the industry is a widespread and significant problem. Camacho and Bagarinao (1987) have shown a positive correlation between Philippine municipal fishery catches and mangrove area utilisation.

Interactions between aquaculture and native species
Over the past five years, the source of wild fish seed (e.g. milkfish and shrimp) has become so scarce that the annual demand cannot be met. This has prompted the proliferation of land based finfish and shrimp hatcheries, but there are still problems of uneven distribution of fish seed supply, artificial shortages, hoarding and fry smuggling. This is now considered a nation-wide problem in the brackishwater fish pond industry. As efforts by wild fry collectors have doubled or even tripled there is a possible loss of diversity of native fish stocks and reduced natural productivity. Operators still prefer to use wild seed as opposed to hatchery produced fry because it is considered to be of higher quality, with greater resistance to stress and diseases. Due to the proliferation of fish farms and hatcheries, disease outbreaks in farm and wild stocks are common in some parts of the country.

Importation of live fish for aquaculture purposes, stocking in natural waters and the aquarium fish industry have been carried out without consideration of the potential adverse effects. Negative impacts have included depletion of endemic and indigenous populations, introduction of exotic disease agents, and the entry of pests which destroy local crops. It is claimed that Penaeus stylirostris and P. vannamei, imported from Latin America may have introduced disease to local shrimps (Juliano et al 1989).

There have been some positive impacts of coastal aquaculture development on local wildlife including increased productivity of some species used for culture and increased food availability for mammals and birds, particularly due to mollusc culture.

Social conflicts and aquaculture
There has been great competition in mangroves, swamplands and agricultural areas for conversion to brackishwater shrimp ponds (as in Zambales ricefields and Negros sugarland). This has resulted in a loss of livelihood to mangrove dwellers. The pumping of groundwater has resulted in subsidence and salinisation (as in Negros and Panay) causing conflicts with agriculturists, domestic water users and other users of freshwater. The unregulated development of fishponds, cages, pens (as in Manila Bay) and shellfish beds is considered a hazard to navigation. The conversion of bay areas and reclamation of land, restricts access to fishing grounds for artisanal fishermen and causes pollution hazards.

5. INTERACTIONS BETWEEN AQUACULTURE AND THE ENVIRONMENT: IN-DEPTH STUDY

5.1 Culture of marine shrimps in the Philippines

The Western Visayas is one of the (if not the) primary shrimp culture areas in the Philippines. It therefore reports most instances of the environmental problems linked to shrimp farming. This review of the interaction between shrimp farming and the environment is based on information collected for the Western Visayas, also known as Region VI in the Philippines. Discussions with local authorities, researchers and farmers reveal that the nature of the problems are known, but their magnitude is not.

The environmental impact of shrimp farming has not been systematically or continuously monitored by the authorities, neither has the seriousness of the impacts, or their magnitude, been investigated by researchers. Shrimp farmers have protested about the impact of the environment on shrimp farming, but redress has not been obtained. The water courses from which shrimp farmers draw salt and brackish water continue to the polluted by other agricultural industries and households but neither they, nor their representative organisations, have come up with studies showing the magnitude of damage to production.

5.1.1 The culture systems

The cultivated species P. monodon (sugpo), is grown at various degrees of intensity; ranging from extensive (less than 3 post-larvae per m²) to intensive (more than 30 post-larvae per m²). In 1990, the area under pond culture in Region VI (Western Visayas) was reported to be about 8,250 ha; production in 1991 was about 14,900 tonnes. Intensive culture is concentrated on the island of Negros, in its western half, where stocking densities of up to 30 post-larvae/m² were common in the past. Feed was intensively used and ground water pumped to dilute sea water in ponds. In Negros, about 20% of shrimp ponds were converted from sugar cane land, some at high cost. It is reported that some of the larger estates have spent more than Pesos 1 million per ha of pond area, expenditure which must have contributed to the pressure of intensification. In Panay Island, however, most of the shrimp ponds had previously been used as finfish ponds and conversion costs were low. Shrimp farm intensification was also partly supported by the Philippine Government in its search for foreign exchange, which coincided with the drop in Taiwanese production for the Japanese market. Following the decline in export prices experienced by exporters of marine shrimps at the end of 1988 and beginning of 1989, profit margins were squeezed and some producers stopped pumping freshwater having decided that the loss of production as a result of high salinities (35 ppm and above) was much less than pumping costs. Stocking densities also fell.

5.1.2 Interaction between the environment and shrimp farming

Impact of environment on shrimp culture
Water provides the environment for shrimp culture and, as such, impacts on the quantity and quality of shrimps produced are related to water quality. Thus, when we consider the environment's impact on shrimp culture we are considering alterations in water quality (usually man-made) which make it sub-optimal for shrimp, generally referred to as pollution. In the Western Visayas, shrimp farmers classify the main sources of pollutants for water used in shrimp farming as: (i) household waste; (ii) agricultural run off; (iii) industrial run off and (iv) aquaculture run off. Pollution levels in intake waters have generally not been monitored, with the exception of three studies for the first of which a report is available. They are:

1. A study of water quality along the Major River undertaken by the Negros Prawn Producers Marketing Co-operative Inc.;

2. A study of the effluent from sugar mills and prawn farms being undertaken by the University of the Philippines in the Visayas; and

3. A study of the quality of waste water from sugar mills, undertaken by the DENR office in Negros Occidental.

The brackish and/or salt waters used by shrimp farmers is known to be polluted from four main sources but, given the lack of monitoring, no breakdown of the relative importance of each is available. A recent study conducted on behalf of USAID, reports that there is an increasing awareness amongst shrimp farmers that self-pollution may be one of the more important causes of water quality problems in shrimp farms.

Deterioration in water quality has potentially three serious consequences for shrimp farmers:

1. Increased susceptibility to disease;

2. A longer culture cycle; and

3. Mortalities during periods of heavy pollution.

The disease referred to is the MBV and more recently the Infectious Hyperdermal and Hematopoietic Necrosis Virus (IHHNV) has been identified as an agent causing poor growth and mortalities. In Panay and Negros, some argue that the general deterioration in pond water quality has contributed to a decrease in shrimp performance. It used to be possible to grow P monodon to 33g in a culture cycle of 120 days, but now it generally takes at least 160 days. Other farmers maintain that the deteriorating quality of shrimp feeds is to blame (Mr Hugo. R. Corral, Jr, pers comm) and others say that the main reason is a genetic deterioration of the cultured species. At this point it should be noted that local researchers warned of this hazard before intensive culture was introduced and so it could be argued that shrimp farmers knowingly brought this problem on themselves.

Shrimp farmers downstream of sugar mills, suffer mortalities due to pollution from mill wastes channelled into local surface waters. This pollution is intermittent and momentary, but not less harmful. One estimate (by the local government) placed the number of farmers in Negros who suffer from this sort of pollution at between 4 and 10%. Shrimp farmers located close to rice farmers, complain about the use of chemicals in rice fields, which are carried to the shrimp farms and cause mortalities. The local authorities also estimate these farmers to be in a minority.

Self-pollution is a particular problem in those areas of Negros island where ponds are fairly far from the sea. The canals carrying brackishwater back and forth to the sea are not felt to be adequate to carry the volumes of water needed to achieve an effective exchange of water between high tides. So far, the farmers have had little support from the local administration in their attempts to manage environmental impacts on their shrimps, however, this has forced farmers to look for solutions elsewhere. The concept of cleaning both incoming and outgoing waters is now being discussed and implemented by some. Amongst the methods are the use of reservoirs both for the incoming and the outgoing water. Also, the introduction of “bio-filters”, in the form of bivalves and seaweeds (Gracilaria sp.), is now under consideration by farmers.

Impact of shrimp culture on the environment.
In the Western Visayas shrimp culture is reported to have had the following kinds of direct impact on the environment:

1. Contributed to the reduction of mangrove forests;

2. Salinisation of fresh water aquifers;

3. Salinisation of agricultural lands; and

4. Pollution of coastal water courses.

Subsidence of land due to extensive pumping of fresh water is reported not to have occurred. Again, given the low level (almost absence) of monitoring of shrimp culture activities, there are no quantitative estimates available for any of these four categories of impact. In economic terms it would appear, however, that the effects are small, i.e. that the value of the negative consequences is probably inferior to the value of the wealth generated through the export of shrimps. This does not necessarily mean that those that suffer the impacts (including future generations) have been adequately compensated from the wealth generated.

Mangrove forest
Although it is recognised that mangrove swamps serve as nursery grounds for juvenile fish and shrimp; and also as the preferred environment for some adult fish, there is no quantified data available on the effect that the reduction in mangrove area has had on the Western Visayas. Up to 60% of mangrove denudation has been attributed to fish and shrimp culture. Over a 70 year period (1920–1990), the rates of mangrove conversion to fish ponds were estimated to range from 1,000 to 24,000 ha per year (Primavera, 1993). In the beginning of the 1990's in the Negros, the area had shrunk to 500 ha. The effect of this reduction in the abundance of marine life and consequently on marine fisheries is not known.

Some shrimp farmers report negative effects resulting from the lack of respect of the rule which aimed to maintain a “green belt” of mangrove along the shore. The first negative effect is simply that of less protection from floods and winds. The second effect is the result of the construction of fish and shrimp ponds out into the estuaries of rivers, which reduces the magnitude of tidal water exchange. This is detrimental to water quality for those farms which are situated higher upstream, and which draw their water from the estuary concerned. This effect is compounded by the fact that fixed structures, such as fish traps, are permitted in estuaries and streams.

Salinisation of freshwater aquifers
This issue appears to be limited to Negros island. Some of the shrimp farmers at Negros are aware, through the complaints of neighbouring populations, of the effects that their pumping of freshwater has had on the access of others to freshwater. Some farmers have introduced compensatory measures, others have reduced pumping. One is reported to be supplying water by truck to those affected.

Salinisation of aquaculture lands
Fishery researchers are not aware of this issue. However, it was reported by those concerned that the magnitude is small, a band of some 20 meters around a pond, and seen from the economic perspective this loss is more than compensated for by the value of the shrimps produced. It is also believed that the original quality of the soil can be restored (using manure and lime) but at an effort.

5.1.4 The legal context

The development of shrimp culture has taken place within an incomplete legal environment in the Philippines. Laws have covered only some of the actions of importance to shrimp farming, and enforcement has been weak where legal provisions have existed.

Legal provisions
Presidential Decree 704 stipulates that coastal mangrove swamps are public property, that fish ponds can only be constructed in areas publicly designated as alienable and disposable, and leases for a period of 25 year can be granted. Also it is stipulated in the same PD that a protective belt varying in width from 15 to 100 meters, depending on the nature of the shore line, shall be left intact and in those cases where there is no protective belt, such a belt shall be developed through reforestation of the mangrove. The enforcement agency for these provisions is the Department of Environment and Natural Resources (DENR).

There is unanimity amongst shrimp farmers and researchers that these later two provisions have not been respected and that fish farms have been allowed to develop out to the shore-line. No protective zone has been developed in areas where it does not exist.

Presidential Decree 1151 stipulates that permission from the EMB and National Water Board must be obtained before a deep well is drilled. The National Water Board is part of DENR which is the regulatory agency. This provision was not effective on Negros Island during the boom of intensive shrimp farming 86/87. The local Provincial Governor therefore introduced a rule that the Provincial Government should issue licences regulating deep wells in Negros Occidental. By the time this rule came into force, the drive towards using fresh water had exhausted itself.

The Department of Agriculture has placed a ban on the use of organotin and according to their FPA Circular (No. 1), this ban is already effective. The ban is seen as unjust by shrimp farmers who consider themselves small offenders compared with rice farmers. Rice farmers use pesticides every 14 days during the summer months, whereas the shrimp farmer need only use pesticides once every three years to keep his farm free of snails and undesirable organisms in the pond.

The requirement for an Environmental Impact Statement before the construction of fish ponds are approved by DENR as introduced in 1977 by Presidential Decree No 1586.

Missing legal provisions
Some shrimp farmers are of the opinion that the authorities need to introduce regulations which will control the free flow of water in all water courses. The obstruction of water courses with fixed installations (fish ponds, fish traps, and other constructions) can have serious impacts on the flow of water, with attendant effects on water quality and marine life. For similar reasons shrimp farmers maintain that the “right to pollute” water courses must be controlled.

Farmers and local authorities need protection from the free use of ground water, particularly in those areas where ground water reserves are low in relation to demand. The present provisions for control of fresh water use are insufficient.

Observation
Had it been possible to enforce the existing laws and regulations most of the harmful environmental effects caused by shrimp culture would have been, if not avoided, at least reduced considerably. A major reason for the difficulty of implementation (both with regard to clearing of mangroves, pumping from deep wells) is the prevailing opinion, both in the administration and the private sector, that the legal provisions do not apply to land held as private property, that is to which the owner has a title deed.

The negative impacts on shrimp farming arising through the use of polluted waters, or waters with inappropriate quality, cannot be said to have been caused by lack of enforcement, as there is no legislation which regulates the introduction of municipal refuse or industrial effluent in water courses.

5.15 Discussion

Economists refer to the problem as the case of “externalities”. By this they refer to those situations in which the productive activities of individual “a” influence in a positive, or negative, manner the result of the productive activities of individual “b”. If the influence is negative it means that either individual “b” obtains less gross income, or experiences higher costs, because of the activities of individual “a”.

The development of shrimp farming in the Philippines shows that, unless there is a means of implementing regulations, efforts at management are meaningless. The main lessons to be applied in regions about to develop coastal marine shrimp farming are:

1. Local government must have the legal framework, the resources and the will to enforce regulations for any management scheme to be effective;

2. Baseline data should be obtained about the resources to be used/replaced from shrimp culture (water quality, mangrove swamps);

3. Specific guidelines should be established for:

   1. use of fresh and salt water;
   2. installation of permanent structures in flowing waters; and
   3. zoning should be introduced;

The first point, enforcement capability, is obvious and therefore it is frequently overlooked and enforcement capability taken for granted. This is a mistake as where it is not available development of management schemes is wasted effort. Baseline measurements are essential in order to make it possible to undertake meaningful monitoring as development proceeds.

Specific regulations may take the form of authorisations, prohibitions, or fees. Given that water is a scarce resource, the use of water should be charged for. Where there is no other use for the water abstracted, e.g. with saltwater, there should be no charge if it is returned in the same state it was obtained. All other uses, of which extraction of ground water is one, should be charged for.

5.2 Culture of tilapia in the Philippines

The introductions of several tilapia species in the country and proliferation of culture techniques has resulted in the fast exploitation of available resources for culture. Traditionally, Oreochromis mossambicus were widely caught in brackishwater ponds as secondary species which are not intentionally cultured and often regarded as pest species. It was not until after the introduction of O. niloticus sometime in the late 1970s that widespread culture and production of tilapia expanded to almost all freshwater areas of the country.

Culture is practised either in floating net cages or fish pens along landlocked lakes, rivers, reservoirs and freshwater ponds. The culture system varies from extensive, semi-intensive to intensive culture. Fry and fingerlings are supplied by hatcheries and breeding technology is highly developed by some operators. In recent years, culture techniques have been improved and market prices have been competitive with commercially valuable marine fishes.

In the Philippines, the largest known lake, Laguna de Bay, is the most congested area where tilapia culture is practised. This is also where the complex issues of environmental resource use have been brought into focus as it has a large catchment and is surrounded by urban and industrial establishments. The present study will focus on interactions between the aquaculture and the environment, with particular reference to tilapia farming.

5.2.1 The culture system

Tilapia farming systems in the Laguna de Bay vary from extensive fish pens (which can be hectares in size) to floating net cages of 2 × 2 m with intensive stocking densities of 5–10/m², using commercial pelleted feeds. The culture period ranges from 4–6 months depending upon the desired size or weight of the fish to be grown. The average market size is harvested at 4–6 pieces per kilo but local restaurants and hotels prefer 1–2 pcs per kilo for special orders.

Laguna Lake, just like all other major lakes in the Philippines, has recently been exploited with unregulated culture systems because of the increasing demand in the culture of this species. Expansion of areas has not been controlled and stocking densities and farm inputs have not been regulated. Due to the scarcity of milkfish fry supply which is the primary culture commodity in the lake, massive conversions to tilapia farming have been evident adding to its competitive price with the milkfish.

5.2.2 Interaction between the environment and tilapia farming

Impact of the environment on tilapia farming
The geographic location of the Laguna Lake dictates the major ecological interactions in its ecosystems. The lakeshore is surrounded by towns, bounded by a number of cities and its water drains through a big river system to Manila Bay, which also influences the lake with seawater intrusion during high tide. The Pasig river which links the lake to Manila Bay is bounded along its embankments with factories and oil depots. Urban wastes and agricultural run-off also contributes to the high industrial pollution resulting in eutrophication of the lake. Massive “fish kills” and disease outbreaks in cultured fish are frequently experienced.

Impact of tilapia culture on the environment
The expansion of tilapia culture in Laguna de Bay also showed negative effects on the environment as evidenced by the congestion of fish farming structures sprawled all over the lake area. Despite several attempts by the Government to regulate the establishment of fish culture facilities within the lake, increased demand and exploitation of the resources has contributed to the critical condition of the lake.

The increase in numbers of fish pens and cages in the lake has grossly contributed to the deterioration of its ecological balance. The natural carrying capacity of the system was overloaded by the BOD requirements of the cultured fishes. Levels of nutrients in the lake were very high and the situation is aggravated by chemical discharges from large factories surrounding the lake that induce algal blooms. The seasonal occurrence of the phytoplankton blooms is also thought to have caused the “off-flavour” taste phenomena to cultured tilapia and other finfishes within the lake.

Intensification of the culture system also shows a direct effect on the sediments with decomposing, uneaten feed particles forming a sludge beneath the cages. The accumulation of sludge encourages the formation of bacterial populations and which (it has been speculated) may have enhanced the development of EUS (Epizootic Ulcerative Syndrome).

5.2.3 The legal context

Tilapia farming in freshwater lakes has developed in similar manner to the shrimp industry, within an incomplete legal framework. There are provisions of rules and regulations in the utilisation of lake resources for aquaculture, but enforcement of the laws has been neglected.

Legal provisions
The lake and lakeshore development within the Laguna de Bay ecosystem is generally governed by the Philippines Environmental Policy otherwise known as Presedential Decree No. 1151. Furthermore, all projects in the Philippines need to secure an Environmental Compliance Certificate (ECC) from the Environmental Management Bureau (EMB) prior to project implementation as mandated by Presedential Decree No. 1586 (also known as Philippine Environmental Impact Statement System). The frameworks of both Presedential Decrees are comprehensive in scope, setting forth various provisions advocating the right to a healthy and sound environment such as the installations of compulsory waste treatment facilities.

Set forth under the Laguna Lake Development Authority (LLDA) mandates are special promulgations relevant to the lake resources and management. Among others are zonation and development plans, including the package recommendations of the SOGREAH (1991) study.