Impact of submarine groundwater discharge on fish and zooplankton abundances and on early biofouling processes in a coastal la goon of Tahiti, French Polynesia@en

Submarine groundwater discharge (SGD) in to the sea is widely spread and investigated. However, on the impact of SGD on marine organisms in turn very view work has been done. For a better understanding of the interaction between SGD and its surrounding organisms, the impact of SGD on fish and zooplankton abundances as well as on the early biofouling process was investigated in a coastal la goon of Tahiti, French Polynesia. This study is based on the hypothesis of an enhanced biological production due to increased amounts of nutrient input caused by terrestrial fresh water supply to the sea. Presented data showed a significantly larger growth of algal turfs exposed to the freshwater spring. Plankton evaluations suggest ed slightly higher wet weights and abundances around the freshwater. The implemented stationary photo sampling of fish resulted likewise in a significantly higher fish occurrence around the freshwater spring. The presented data suggest that the elevated nutrient concentrations transmitted by SGD may cause a bottom up control resulting in higher zooplankton and fish abundances around SGD.海底地下水排泄（Submarine Groundwater Discharge, SGD）入海的现象分布广泛且已得到广泛研究。然而，针对海底地下水排泄对海洋生物的影响，相关研究却相对匮乏。为深入明晰海底地下水排泄与其周边海洋生物间的相互作用，本研究于法属波利尼西亚塔希提岛的一处沿岸泻湖开展实验，探究了海底地下水排泄对鱼类、浮游动物（zooplankton）丰度以及早期生物污损（biofouling）过程的影响。本研究基于以下假说：陆地淡水入海带来的营养盐输入增加，会提升海洋生物生产能力。本次研究呈现的数据显示，暴露于淡水泉周边的藻席（algal turfs）生长量显著更高。浮游生物分析结果表明，淡水泉周边的浮游生物湿重与丰度略高。采用固定式摄影采样法开展的鱼类调查结果同样显示，淡水泉周边的鱼类出现频次显著更高。本次研究呈现的数据表明，海底地下水排泄输送的升高浓度营养盐可能引发上行控制（bottom-up control）效应，进而使海底地下水排泄周边区域的浮游动物与鱼类丰度得以提升。