Title: 40 Years of Aquaculture Development and Management in the Dagupan City Estuary System

Speaker: Dr. Michael Rice (University of Rhode Island)

Host: Jonas Miller

Abstract: 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.

Contact imetdirectorsoffice@umces.edu for meeting details.