飞云江与鳌江口海域夏、秋季环境因子与浮游生物的分布变化

Change in Distribution of Plankton as Affected by Environmental Factors in the Estuaries of Feiyunjiang River and Aojiang River in Summer and Autumn

于2010年8和11月调查了飞云江口和鳌江口海域（27°45 ～ 27°08′N,120°05～120°09′ E）浮游动植物的空间分布特征,分析其与主要环境因子如营养盐和悬浮物等分布的相关关系.结果表明,无机氮、活性磷酸盐和悬浮物浓度由河口区域向外逐步减小,盐度和pH值则逐渐增加.8月鳌江和飞云江口部分区域溶解氧浓度较低;表层海水温度8月在调查海域中部有一带状高值区,11月在飞云江口外有一带状低值区.ρ（Chl-a）在8月较高,平均值为5.2 μg·L^-1;11月较低,平均值为0.9μg·L^-1.浮游植物丰度在8月较高,平均值为2 344.6×10^4 m^-3;11月较低,平均值为33.1×10^4 m^-3.近飞云江口区域浮游植物丰度和小型浮游动物密度较高,由河口区域向外逐渐降低.浮游植物丰度与多数环境因子相关性不高,仅在8月与盐度呈显著负相关（P＜0.05）.河口区西太平洋潮波、陆域径流人海、沿岸流以及海域地形条件共同决定飞云江口和鳌江口的生态过程,丰水期陆域径流对近岸海域浮游生物分布起主导作用.

Spatial distribution of phytoplankton and zooplankton in the waters around the estuaries of Feiyunjiang River and Aojiang River （27°45-27°08′ N,120°05-120°09′ E） were investigated in August and November 2010 for analysis of its relationship with some major environmental factors,such as nutrient salts,suspended substances （SS）,etc.Results show that concentrations of inorganic nitrogen,labile phosphate and suspended substances gradually decreased,while salinity and pH gradually increased from the estuary waters to offshore waters.In August,the parts of the estuaries were found to be low in DO concentration,and a strip of high sea surface temperature （SST） was in the center of the investigated region.In November,a strip of low SST was observed in the estuary of Feiyunjiang River.The average concentration of chlorophyll-a in August and November was 5.2 and 0.9 μg · L^-1,respectively.The abundance of phytoplankton was quite high in August,averaging 2 344.6 × 10^4 m^-3,but quite low in Novermber,being 33.1× 10^4 m^-3 on average.The distributions of phytoplankton abundance and meso-zooplankton density were similar to that of SS concentration in trend,being high in the estuary of Feiyunjiang River and declining towards the offshore zone.Phytoplankton abundance was not much related to environmental factors,except for in August（P〈0.05） when it was negatively related to salinity.West Pacific tidal waves,inland runoff via rivers,coastal currents and sea topography are the factors that jointly determine the ecological processes of the estuaries of Feiyunjiang River and Aojiang River.However,during the high water season,inland runoff via rivers stands out as the dominant factor influencing plankton distribution.