春秋季台州湾海域鱼类资源的时空分布特征研究

为研究浙江近岸河口海域鱼类资源分布的时空变化特征,利用2010年4月(春季)和10月(秋季)鱼山渔场台州湾海域底拖网游泳动物资源调查资料,分析了台州湾鱼类资源量的时空分布特征和优势种、温度、盐度、水深等因素对鱼类资源量和分布的影响。结果发现,鱼类尾数密度和质量密度变化趋势一致,秋季鱼类质量密度和尾数密度均远远高于春季;春季调查海域鱼类密度北部高于南部,秋季截然相反。回归分析显示,两季优势种对鱼类资源量变化均有密切关系,其中,龙头鱼对鱼类资源量的贡献率明显高于其他物种,两季均为第一优势种。调查海域底层温度与鱼类质量密度和尾数密度均呈显著的正相关关系(PW=0.001,PN=0.009),水深与资源量相关关系不显著(Pw=0.067,PN=0.051),春季20 m以内水深鱼类资源量较高,而秋季密度高值区水深均大于20 m。研究表明,台州湾海域春秋季鱼类资源密度季节变化明显,空间差异显著,底层水温是主要影响因素。

Analysis of temporal-spatial distribution of fish resources in the Taizhou Bay in spring and autumn

To identify temporal-spatial distribution of fish resources in Zhejiang coastal and estuary regions,based on the data from bottom trawl fishery resources in Taizhou Bay in April and October 2010,The temporal and spatial distribution and the influence of dominant species,temperature and salinity,water depth and other factors on the amount and distribution of fish resources were analyzed.The result showed that the change trends of individual densities and weight densities were consistent,In April,both of individual densities and weight densities were higher than those in October in terms of seasonal distribution.In the spatial distribution respect,the fish resources densities in the north studied area were obviously higher than those in the south in April,however,it was obviously opposite to October.According to stepwise regression analysis of fish resource density with dominant species and hydrological factors,in two seasons,the variation of resource density had significant correlation with all the dominant species,Harpodon nehereus is the most dominant species because of its highest contribution rate to the weight densities and Individual densities.Meanwhile,the fish resource density had significant correlation with surface temperature(P_W=0.001,P_N=0.009),and depth had insignificant correlations with resource density(P_w=0.067,P_N=0.051).The area whose depth was less than 20 m had higher amount of fish resources density in Spring,while the high values of density at greater than 20 m depth in Autumn.This research showed that the fish resources had a significant seasonal alteration and spatial variation.Bottom water temperature was the most important factor that affected variations in the fish resources in the Taizhou Bay.