Eutrophication of marine ecosystems is a global problem, particularly in a changing climate and the spreading of Oxygen Minimum Zones (OMZs). The eastern Arabian Sea has both seasonal and permanent/perennial OMZs, but our understanding of the fauna there is extremely poor. So, this study investigated the composition and physiological status (alive or dead) of zooplankton (copepods) in the two OMZs. The study was accomplished by employing a Multiple Plankton Net and vital staining method. Our results showed for the first time that the oxygen deficiency adversely impacted the physiological status of copepods in OMZs which was reflected as (a) a two-fold decrease in zooplankton in the more intense oceanic OMZ compared to the coastal OMZ, (b) a marked increase of dead copepods in both OMZs (50 to 60 %) compared to normoxic waters (35 %) observed in previous studies and (c) higher copepod carcasses (50–70 %) and lower copepods larvae in the intense oceanic OMZ.

中文翻译：

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东阿拉伯海最低氧区桡足类的生理生态状况


海洋生态系统的富营养化是一个全球性问题，尤其是在气候变化和最低氧气区 （OMZ） 的扩张的情况下。阿拉伯海东部有季节性和永久/多年生 OMZ，但我们对那里的动物群的了解极少。因此，本研究调查了两个 OMZ 中浮游动物（桡足类）的组成和生理状态（活着或死去）。该研究是通过采用多重浮游生物网和生命染色方法完成的。我们的结果首次表明，缺氧对 OMZ 中桡足类的生理状态产生了不利影响，这反映为 （a） 与沿海 OMZ 相比，更强烈的海洋 OMZ 中浮游动物减少了两倍，（b） 与先前研究中观察到的常氧水域 （35%） 相比，两个 OMZ 中死亡桡足类动物的数量显着增加（50% 至 60%），以及 （c） 较高的桡足类尸体 （50-70%） 和较低的桡足类幼虫强烈的海洋 OMZ。