The objective of this research project is to develop the scientific base for the sustained and rational utilization of the available recources of Laguna de Bay, philippines, by men, especially by Eishery and aquaculture as important protein sources. To achieve this, this study aims at developing a dynamic ecological model of Laguna de Bay. With this model, the effects of different management schemes for fishery and aquaculture as well as for land use in the watershed on fish yield and trophic situation will be tested. At the final stage, all relevant data on Laguna de Bay will be combined into an ecological model for rational utilization of the lake.
The structure of this lake model will be applicable to other tropical inland and waters and coastal lagoons endangered by pollution and uncontrolled intensification of fisheries and aquaculture, especially those close to urban areas with high population pressure.
In the first stage of the study, data necessary for identifying and quantifying the biological processes occuring in the Laguna will be collected and used for the establishment of mathematical equations. Parallel, an intensive research programmewith field and laboratory experiments on important processes of the lake system will be set up. For tracing aquatic food chains, samples from foods and fish tissue will be analysed for the isotopic composition (dC and dN) of their protein and ether soluble fraction. Phyto- and zooplancton, algae/detritus complex and sediments will be treated the same way, water carbonates will be analysed for dC. Other experiments will elucidate the nutritional value of natural feeds, eutrophicating effects of dieferent balanced feeds and the effect of mineral nutrients on the aquatic system.
Concurrently the identification of the socioeconomic situation of fishermen and aquaculturists and how they are affected by the deteriorating ecological situation will be investigated.
The multi-disciplinary and participatory approach of integrating biological, physico-chemical and geographic data into a model will allow for a sustained resource utilization.