为了解近岸河口海域蟹类资源分布及其与主要环境因子的关系,利用2010年春季(4月)和秋季(10月)椒江口海域渔业资源调查资料,分析了椒江口蟹类资源密度的分布、优势种以及水团、水深等环境因子对蟹类数量和分布的影响. 结果表明:椒江口海域春季和秋季蟹类平均重量密度分别为74.57 kg km-2和62.73 kg km-2,尾数密度均值分别为3.63 × 103 ind. km-2和5.07 × 103 ind. km-2;蟹类密度平面分布特征,春季在调查海域蟹资源密度中部高于两侧,高密度区出现在椒江河口北部区域,尤其是受椒江径流影响明显的北部岛礁海域;秋季则两侧明显高于中部,尤其是大陈岛东南部受台湾暖流和浙江上升流影响的海域以及受椒江径流影响明显的西北部海域. 逐步回归分析表明:椒江口温、盐度和水深与蟹类资源密度均无显著的相关关系;春季和秋季,日本蟳(Charybdis japonica)对蟹类资源密度贡献率均最大,为两季节唯一的优势种. 本研究表明,椒江口蟹类资源密度分布不均匀,水团交汇处是蟹类资源密度的高值区,主要环境因子对蟹类资源分布影响不明显.
To understand the relationship of crab resources distribution with the main environment factors in the coastal and estuarine waters, a study was conducted to define spring and autumn distribution patterns of crab resources in the Jiaojiang Estuary and to relate these patterns to environmental variations in April and October 2010. The influences of dominant species, water temperature, salinity, distribution depth and abundance of crabs were evaluated. The result indicated that the average weight densities in April and October were 74.57 and 62.73 kg km-2, respectively. Yet the average number densities were 3.63 × 103 and 5.07 × 103 ind. km-2,respectively. In April, both of the weight and number densities in the central studied area were higher than those in both sides. In October, however, both weight and number densities in both sides of the studied area were obviously higher than those in the central. The crabs stayed continually at Jiaojiang coast in April, especially the northern coast, where the water was affected by the runoff of the Jiaojiang River. But higher density of crabs was observed in northwestern and southeastern waters in October, due to the runoff of the Jiaojiang and Taiwan warm currents. According to stepwise regression analysis on crab abundance and hydrological factors, the crab abundance had no significant correlation with temperature or other factors. In both spring and autumn, Charybdis japonica was the most important dominant species. This research showed that the crab resources distribution is nonuniform, with the highest density in the watermasses and no obvious effect of the main environmental factors on distribution of crab resources.