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Developing New Tools To Document Waste Nutrient Flow in Tropical and Subtropical Marine Fish/Bivalve Integrated Culture Systems
EPA Grant Number: U916238Title: Developing New Tools To Document Waste Nutrient Flow in Tropical and Subtropical Marine Fish/Bivalve Integrated Culture Systems
Investigators: Watts, Jennifer L.
Institution: University of California - Davis
EPA Project Officer: McClure, Karen
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $92,653
RFA: STAR Graduate Fellowships (2003)
Research Category: Aquatic Ecosystems , Academic Fellowships , Fellowship - Oceanography and Coastal Processes
Description:
Objective:The objectives of this research project are
to: (1) examine and compare the pathways of nutrient flow (with an emphasis
on nitrogen) through
experimental fish/bivalve integrated culture systems in two distinct study
sites, an arid subtropical coastal lagoon near La Paz, Baja California Sur,
and the tropical Gulf of Nicoya in Costa Rica; and (2) test the hypothesis
that geochemical analysis of bivalve shell material that combines 
18O, 13C
together with 15N values obtained from nitrogen in the shell organic matrix
can produce a temporal record of shell 15N from which inferences can be made
about variation in 18N from the particulate organic matter bivalve food resources
found in coastal ecosystems.
This research project involves characterizing relevant aspects of physical (e.g., currents) and biological processes near fish cages and at control sites using a multifaceted approach that combines simulation modeling with empirical data collection, plus some new applications of stable isotope geochemistry, that can provide insight into the fate of nutrient wastes released from fish cages. The data set collected at the two study sites will be used to test the hypothesis that nutrient inputs originating from fish cages are identifiable and can alter ecological processes, such as nutrient uptake relationships, in coastal environments. This research project blends investigation into practical questions relevant to the management of coastal fish farm development with the generation of new tools for the study of aquatic ecosystems that together can shed light on the behavior of nutrient wastes in coastal environments. With the limited capacity for capture fisheries to meet future demand for seafood, fish farming in the coastal zones, especially in low-latitude developing countries, will become a priority. This research project will point the way to the implementation of environmentally sensitive net-pen culture of marine fish in tropical and subtropical regions of the world. The proposed new geochemical techniques to intensively study a known source of nutrients also have great potential applicability to other locations and situations, and as such, will provide knowledge that can enhance management of coastal zones worldwide.
Supplemental Keywords:fellowship, waste nutrient flow, marine fish/bivalve integrated culture systems, marine fish, subtropical, tropical, nutrients, nutrient wastes, California, CA, Costa Rica, nutrient flow pathways. , Ecosystem Protection/Environmental Exposure & Risk, Water, Geographic Area, Scientific Discipline, RFA, ECOSYSTEMS, Aquatic Ecosystems & Estuarine Research, Nutrients, Aquatic Ecosystem, Biochemistry, Aquatic Ecosystems, Ecology and Ecosystems, State, International, California (CA), subtropical marine fish, La Paz, photochemistry, oceanography, nutrient concentrations, coastal environments, nitrogen, coastal ecosystem, nutrient cycling, Costa Rica, estuaries, dissolved organic matter, ecosystem stress, ecosystem monitoring, nutrient dynamics