| Overall investigation of physiochemical features of fishery waters quality were conducted in Guangzhou from 2004 to 2006. At the basis of these investigations, integrate evaluation of trophic state and environmental status was made. This paper tried to make a probing research on sustainable utilization assessment of fisheries resource and early-warning system from both theory and practice. Teoretical base for the reasonable utilization of fishery resource and ecological management of environment were provided using peculiar fishery resoureces' biological and economical feature and ecological means. The main results are as follows:The main pollutants in Guangzhou's natural fishery waters were nitrogen, DO, BOD, COD and petroleum and in surface sediments, heavy metals and petroleum, too. Characteristics of the pollutants distribution in time and space of Guangzhou's natural fishery waters were seasonal variations that higher concentration in the dry season than in the flood season and the concentration decreased from the Zhujiang River to Dongjiang River and Beijiang River in horizontal distribution. The concentrations of heavy metals distributed like the waters in space and in time, vice versa.Assessment on potential ecological risk due to heavy metals pollution in sediment in Guangzhou's natural fishery waters indicated that the maximum potential ecological risk index was Cd, and next, Hg was the middle grade. The other, Cu, Pb and As were insignificance. Due to the higher index of Cd, the potential ecological risk indexes of heavy metals were high. Comprehensive evaluation of Guangzhou's natural fishery waters by fuzzy mathematics showed that water quality in the Dongjiang River and Beijiang River satisfied environment standard for sort 1 and 2, but in Zhujiang River was serious polluted and closely approximated environment standard for sort 4 and 5.The main pollutants in Guangzhou's aquacultural areas were total coliforms and petroleum. Source water quality was better than aquicultural water in whole. The monitoring data collected from the water body of Guangzhou's aquacultural areas were analyzed with the method of comprehensive pollution index, further the pollution status and trend were assessed, the result show that the water quality of the areas belongs to slight to heavy pollution. Its regional character was obvious.Based on the study of Aquatic Products qualities in Guangzhou, we can discovered, with the increasing of fisheries culture production and the expanding of fisheries culture scale, the fisheries culture environment and the diseases on main culture species are muchd worse, and the problems of drug avusing are very worse too, which induce the quality of fish and decrease fisheries products production. The importance and urgency of healthy cultivation and food safety of aquatic products are discussed from the respects of culture production, market circulation and human food safety et al, and some suggestions and contermeasures are put forward from the repects of technology, economy, policy and regulation.And above all, environment quality of Guangzhou's fishery waters was not optimistic. The main pollutants in the waters were organic ones and nutrients and in sediments were heavy metals. The waters were in severe eutrophication level and too bad for fishes. There were Potential dangers of quality safety in aquatic products and aquaculture. The reasons to cause this kind of current situation were mainly as follows: the poor exchanging capacity of water body, the input from land contaminations and the self-pollution of aquaculture.
|
PDF Full Text Request