Catch Composition And Effects On Fish Resources Of The Set-net Along The Coastal Water Of Haizhou Bay

Stow net is a traditional fishing gear in Shandong province. Because of its lowcost, low energy consumption and stable output, stow net has become an importantfishing method in HaizhouBay. As a kind of passive filter fishing gear, mesh size ofcodend of stow net is relative small, and a lot of young fish or shrimp are oftenbycatched. With the rapid development of the set-net fishery, fishing effort isgradually increasing to deteriorate, resulting in near-shore resources growingrecession. It is necessary to conduct research on the set-net catch composition and itsvariation, analysis of the proportion of by-catch, and analysis stow net fisheryeconomic, to provide a reference for the management of fisheries resources.Based on the survey date in Haizhou Bay area during March2011to December2012, draw sheets mesh netting expanded view and schematic. The results showedthat: the composition of dominant species in catches obviously varied in variousseason. There were dominated by Syngnathus acus，Amblychaeturichthys hexanema，Charybdis bimaculata，Octopus variabilis，Enedrias fangi，Oratosquilla oratoriainspring, by Larimichthys polyactis， Amblychaeturichthys hexanema， Portunustrituberculatus，Loligo joponica，Trachypenaeus curvirostris in autumn, and byAmblychaeturichthys hexanema，Oratosquilla oratoria， Alpheus heterocarpus，Leptochela gracilis，Alpheus Japonicus in winter.Mostly economic species economicspecies larvae, Larimichthys polyactis, Trachypenaeus curvirostri, Portunustrituberculatus， Oratosquilla oratoriaand Stromateoides argenteus can catch upspecifications rates were1.57%,69.46%,1.03%,72.32%and1.79%, Trichiurusjaponicus did not meet all of the allowable catch specifications. The fishing log records showed that the September single vessel average netproduction to achieve maximum17.01kg/net,the November average net productionminimum, only2.87kg/net. The set-net output12488~26182kilogram per boat,3to8million annual income per year and per boat. Logging single fishing boat net averageannual production of1,810times the average annual production of single-ship15.822t/y. September single vessel average net production reached the maximum17.01kg/net, December single vessel lowest average net assets, only2.87kg/net.Haizhou Bay inshore set-net annual effective operating days69to174days, set-netannual yield11012kg~26182kg per year, net in the effective operation of the numberof days increased from south to north, and the annual catch of the southern waters ofthe northern waters than high.Set-net annual average expenditure of100,000yuan annual income50,000yuan/boat around, not only economic efficiency is not high, but the lack of sustainable netin force, the fishermen aged32to64years of age,61.7%of the fishermen older than45years of age. Set-net fishery have shown clear declining trend.Defined as bycatch species catch economies catch species larvae andnon-economic kind, set-net catches in a higher proportion of by-catch, Throught theyear,from December to March of the following year, the proportion of by-catch is low,only62.6%~82.6%, a higher proportion in autumn and the proportion of by-catch upto90.4%~93.6%.