Simulation Model for Evaluating the Response of Management Options on the Demersal Resources of Tamil Nadu Coast

The response of different management options on demersal fish catch in Tamil Nadu was examined using simulation model and time series data on catch and effort of demersal resources in Tamil Nadu during 1989-2005. For the simulation study surplus, production model and spectral models were used to simulate effort, yield and biomass. Genetic algorithm was used to estimate parameters of surplus production model. Effort, biomass and yield were simulated for the period 2006 to 2015 under different levels of effort such as reducing by 25%, 50%, and 75% of present level increasing by 25%, 50%, 75% and 100% of present level and also for the present level. The simulation results revealed that when the level of exploitation is kept at 25%, 50%, 75%, and 100% of the present level, the yield falls below the maximum sustainable yield (MSY) level and the biomass is kept above its MSY level. When the exploitation level is increased by 25% of the present level of exploitation, the yield falls below the MSY level in the years up to 2013 and the biomass remains above that at MSY level. But at this level of exploitation, the yield falls above the MSY level and the biomass falls below its MSY level for the years 2014 and 2015. The optimum exploitation level was worked out as 91.25% of the present level of exploitation