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Aquaculture in Dagupan City, Philippines
Abstract
The development of aquaculture in the Agno-Pantal-Calmay River Estuary system of Dagupan City, Pangasinan Province in the Philippines is reviewed. Traditionally, extensive pond culture of milkfish, Chanos chanos and penaeid shrimp was practiced along with culture of mangrove oysters, Crassostrea iredalei, in adjacent estuarine waterways. Netpen culture of serranid groupers in the estuaries began in the early 1980s, followed by intensive fish pen culture of milkfish in the early 1990s. Culture of multiple species and integration with local capture fisheries constituted a de facto form of polyculture. Over intensification of finfish aquaculture led to hyper eutrophication and fish kills beginning in 1996. Official governmental response to the fish kills is reported, and recommendations to prevent future fish kills based upon aquaculture carrying capacity considerations are offered.
... Beveridge, 1984; De LaCruz-Del Mundo et al., 1997;Naylor et al., 2000). Fish kills began in the late 1970s with fish pens located in the Laguna de Bay of the Philippines, then in 1996 in the estuaries of the Dagupan City region, and still later in other areas in the Pangasinan Province of the Philippines (LLDA, 1995;Rice & DeVera, 1998;San Diego-McGlone et al., 2008). ...
... Municipal and provincial officials were invited to explore use of carrying capacity and economic modeling too manage aquaculture in their jurisdictional water bodies to prevent fish kills by stocking density management rather than by outright aquaculture prohibition. Rice & DeVera (1998) and Abery et al. (2005) pointed out that numbers of fish pens and biomass of cultured fish placed into publicly-held water bodies can gradually reach unacceptably high levels because few political decision makers have the knowledge of the concept of excessive biomass loading by fish and feeds, or the more general concept of ecosystem carrying capacity. Additionally in their desire to foster economic growth within their political jurisdictions and to provide funding for worthwhile public works projects, the official issuance fish pen permits is seen as a reliable means for generating funds for public works. ...
... A number of researchers have offered recommendations to manage fish pen aquaculture to reduce likelihood of fish kills. These include: 1) reducing nutrient output by improved FCR through improving feeding strategy and reducing overfeeding ( Boyd et al., 2005); improvements in feeds accounting for species specificity and greater digestability and assimilation efficiency (Thorpe & Cho, 1995;Talbot et al., 1999); increasing the stability of pelleted feeds via the use of a good binder or the use of extruded feeds (Cho et al., 1994); using nutrients from fish production by extractive species, such as mussels, oysters and/or seaweeds in integrated multitrophic aquaculture in marine and brackishwaters and hydroponics in freshwater ( Schpigel et al, 1993;Neori et al. 2004); zoning aquaculture into areas away from sensitive habitats and within the local carrying capacity (White & San Diego-McGlone, 2009); and use of carrying capacity modeling to develop public policy capping the numbers, and sizes of cages, and stocking densities and biomass of fish, and use auctions or other economic policy strategies to maximize monetary return from permits issued by official agencies (Rice & DeVera, 1998;Hanley et al., 1998;Lowry et al., 2005). ...
Many countries of Asia, including Indonesia, have experienced the problem of hypoxic fish kills among fish in netpens and fish corrals in various publicly-held water bodies. Fish farming in enclosures in public water bodies attractive because of low overhead costs in comparison to farming the identical species in constructed ponds. But aerobic bacterial degradation of feed and fish feces in common waters can lead to oxygen depletion, thus causing fish kills. Mass-balance and ecological carrying capacity models and education through and extension programming can be used to inform policy makers as to the maximum biomass of farmed fish allowable before risking hypoxia. Economic modeling of social costs and lost revenue in fish kills can also be used to inform and refine public policies. Tools for managing aquaculture carrying capacity might include managing demand for permits by increasing fees, holding auctions for fixed numbers of permits, or using a system of capping, developing offset charges for finfish effluents, and trading of rights to discharge. In this system, holders of finfish netpen permits would pay an offset to nearby aquafarmers conducting nutrient extractive forms of aquaculture (e.g. bivalve or seaweed farming), thus making often desired Integrated Multitrophic Aquaculture (IMTA) systems more economically viable. The important work of translating recommendations from environmental and economic modeling into practical public policy and management practice requires a considerable effort in extension programming and ongoing exchange among the scientific, industry, regulatory and policy-making communities.
... For example, in freshwater aquaculture, Bardach et al., (1972) and Chen et al., (1995) describe the multitrophic feeding niches of four to six species of carp used in polyculture that include phytoplankton feeders, vascular plant feeders, zooplankton feeders, benthic invertebrate feeders and detritus feeders. A form of IMTA has been practiced traditionally in estuarine aquaculture in the Philippines (Fig. 1) in which oyster farming has been practiced alongside floating cage culture of piscivorous serranid grouper fish, and among fish traps, with some estuarine nutrients being derived from effluents from nearby milkfish farms (Devera and Rice, 1998). This form of defacto IMTA had arisen organically by decades of traditional local use patterns in the estuary. ...
... By 1995, the water quality had deteriorated primarily to the milkfish pens to the point that periodic hypoxic events affected production of groupers and sea bass in the estuary and a business decision was made to halt the production of the groupers and sea bass. In less than two years, massive fish kills were occurring in the estuary and emergency presidential order on 17 October 1997 to dismantle all fish pens from the estuary administered by the Lingayen Gulf Coastal Area Management Commission, reporting to the Office of the President (Rice and DeVera, 1998). This order was only partially implemented. ...
Forty years of management of aquaculture in the estuary system of Dagupan City, Philippines is reviewed from the context of environmental, economic and social sustainability. In the early 1980s, the predominant forms of aquaculture included shallow pond culture of milkfish that drew water from and discharged periodically into the estuary, culture of mangrove oysters, and some floating cage culture of serranid groupers in a simple integrated multitrophic aquaculture system. Beginning in the early 1990s, there was a shift toward intensification of monoculture of milkfish in fish pens at densities approaching physical carrying capacity. Later in 1997, hypoxic fish kills in the estuary brought on calls for better management of aquaculture in the estuary. First efforts to systematically manage the estuary by a formal zoning system began in 2003, accompanied by a major study of the ecological carrying capacity for fish pens in the estuary during the mid-2000s. Beginning in 2013, fish pen management policies were developed and implemented based upon ecological carrying capacity considerations, but these policies remained fluid due to changing priorities of subsequent political administrations. A contingent valuation analysis of lost economic, environmental and social value attendant to degradation of water
and sediments in the Dagupan City estuary due to over-intensification of net pen aquaculture is recommended as a means to develop economics-based policies and incentives for better overall
estuarine management practices, and greater use of integrated multitrophic aquaculture (IMTA) methods.
... As wastes increase, water quality declines, which can lead to increases in fish disease and mortality. For instance, Rice and DeVera (1998) described widespread fish kills associated with intensive net pen culture of milkfish in the estuaries near Dagupan City in the Philippines in 1996 following prior fish kills a few years earlier associated with fish pens in the freshwater Laguna de Bay near to Manila. Since that time, the incidence of fish kills has become more frequent and has become problematic throughout Southeast Asia, including Indonesia. ...
Aquaculture is growing rapidly in Southeast Asia (SEA) and five of the top ten aquaculture producers in the world are countries in SEA. The need to manage aquaculture responsibly is critical. Calculation of aquaculture carrying capacity (ACC) for shared water bodies is necessary for proper management. I review my observations of the needs and capabilities of SEA governments for ACC and then describe a new project in which teams of U.S., U.K. and Indonesian scientists will work on ACC for three Indonesian water bodies – Lake Cirata, Lake Toba and Lake Jatigede.
This is the chapter on small-scale aquaculture within a volume intended as a guide for practitioners engaged in rural sustainable livelihood and food production projects in the developing world. Included in this chapter are fundamentals of aquaculture water quality, selection of sites and construction methods for fish ponds, and management techniques for carp and tilapia which are nutritious and easy to grow in artisanal ponds. The fundamentals of cage culture of fish is also covered, along with the fundamentals of culturing oysters and other molluscan shellfish in coastal waters.
Despite the large amount of academic attention that Southeast Asian shrimp farming has received since the 1980s, few attempts have been made to explain the remarkable variation in the industry's organization across countries and localities. This paper compares the development of shrimp farming in Indonesia, the Philippines and Thailand, arguing that differences can be traced to variations in the initial conditions under which shrimp farming was established, the different ways that national aquacultures are embedded in the regional political economy and the ways in which different countries have responded to the characteristic environmental problems the sector causes itself.
The warm water and high primary productivity of tropical estuaries allows for rapid growth and production of bivalves, but sanitary quality of molluscan shellfish poses one of the single largest impediments to development of international markets. The regulations of the US Food and Drug Administration (FDA) are outlined as representative of regulations governing international trade of fresh and frozen molluscan shellfish. The status of shellfisheries and molluscan aquaculture in several tropical and subtropical nations is presented. A number of developing nations, including Mexico, Peru and the Philippines, have established export markets for fresh scallop adductor meats because they are not considered to be a public health risk. Developing countries, including Mexico, Chile and Korea, export other bivalves by maintaining sanitary water quality in shellfish-growing areas. The inadequacy of coliform bacteria as indicators of shellfish hygiene in tropical waters necessitates research and development of alternative water quality indicators. Strategies for raising shellfish sanitary quality prior to marketing are presented, including transplant or relay, depuration and irradiation of the shucked product. Depuration is especially useful in lowering the risk of environmental, non-faecal pathogens such as Vibrio and can provide extra time between harvest and marketing, to allow public notification in the event of toxic algal blooms.
The factors affecting production of estuary grouper, Epinephelus salmoides, in floating net cages are discussed. The concept of economic production in cage culture is outlined. Economic production of estuary grouper could be achieved by providing a suitable culture site with good water quality; ensuring proper farm management and regular maintenance of cages; preventing disease and ensuring efficient treatment; providing optimum stocking density, a balanced diet, optimal feeding frequency; manipulating fish behaviour by providing artificial hides; and manipulating physiological characteristics, e.g. by the use of growth promoters.
Effects of three temperature treatments on activity, feeding, growth, development and survival of young milkfish (Chanos chanos) were investigated. Low temperature (<22.6°C) and hypoxial condition (<1 ppm O2) decreased activity, responsiveness and food intake; high temperature (up to 33°C) had the opposite effect. Growth and development were fastest in fish maintained in high temperature (). Fish in low temperature () had the least growth and were inhibited from developing into juveniles during the 3-month period. Highest survival () was obtained in high temperature but was not significantly different (P>0.05) from ambient temperature ().