The Sustainable Development Of Fisheries And Environment In Taihu Lake

ECOPATH with ECOSIM is designed for straightforward construction, parameterization and analysis of mass-balance trophic models of aquatic ecosystems. The Ecopath system is built on an approach initially presented by J.J. Polovina for estimating biomass and food consumption of the elements (species or groups of species) of an aquatic ecosystem. Subsequently, it was combined with various approaches from theoretical ecology, notably those proposed by R.E. Ulanowicz, for the analysis of flows between the elements of ecosystems. However, the system has been optimized for direct use in fisheries assessment as well as for addressing environmental questions through the inclusion of the temporal dynamic model, Ecosim, and the spatial dynamic model, Ecospace.The Ecopath with Ecosim software had by late 2000 been distributed to more than 2000 registered users in 120 countries, and more than 100 publications utilizing it have appeared in the scientific literature(Christensen, V, CJ. Walters, and D. Pauly. 2002), Based on Ecopath with Ecosim software, The models of Taihu Lake's ecosystem was found, The quantitative analysis and simulation were maded in Taihu ecosystem, The small-scale fisheries, fisheries policy and the effect of fisheries and environment were researched and simulated, The sustainable development and countermeasure of fisheries and environment were evaluated and analyzed. The mam results are as follows:(1) In order to quantitative analysis and simulate Taihu ecosystem, 19 groups were separated. B, P/B, Q/B or EE must be input for each group, and input diet composition, net migration, capture yield, fish value and profit before Taihu ecosystem equilibrium tested, Using Ecoranger adjust these parameters in order to fit Taihu ecosystem. After equilibrium, the basic estimate, key indices, mortalitis, consumption were output. Network analysis, cycles and path way may be output straightforward after run.(2) Transfer efficiency of energy from producer and detritus are 10.3% and 10.4% respectively, Transfer efficiency of total ecosystemis is 10.4%. Omnivoryindex of ecosystem is 0.186, Total net primary production is 4520.11 t/km2/year, Total P/B is 9.926.(3) Small-scale fisheries and smaller ivdividual are general because of excess exploitation, Taihu fisheries went through no small-scale fisheries to beginning small-scale and main small-scale fisheries. During 1952-2000, yield and rate of small-scale fisheries were increasing. Using Ecopath with Ecosim software to simulate small-scale fisheries development and reasons, Yield and rate of small-scale fisheries were increasing with bigger fisheries decreasing. Yield and rate of Anchovy were increasing. Rate of stocking fisheries increasing, time of embargo and sloping fishing extend, breeding protect area enlarge, fishing rate decreasing, submerged plant comeback are the main policy control small-scale fisheries development. Because of excess capture, yield were increasing with trophic level decreasing. Average trophic level are 3.29, 3.26 and 3.07 respectively during 1952-1958, 1973-1978 and 1979-2000. Trophic level decrease 0.23 with increasing yield during this 50 years. Trophic level of Erythroculter ilishaeformis decrease 0.33 at 1964 to 1981 .(4) Basic on Ecopath model, Ecosim model of Taihu fisheries was founded during 1973-2000 after adjust some fisheries parameters, the simulation results are very close to reality. During 2001-2030, fisheries yield and biomass of groups were simulated and forecasted when fishing rate retained 2000 year's level. Main fisheries policy were simulated and evaluated during 1952-2000, Different fishing rate impact on biomass and yield of different group. The change of biomass and yield if there had no embargo and sloping fishing policy was simulated. Quantitative risk analyse and simulate were used to researching main policy change and development. After input fisheries aim and social target, excellent fisheries policy are selected when ecosystem stabilization, Biomass and yield are simulated, amount of...