CSIR-National Institute of Oceanography, Regional Centre, Kochi, India.
CSIR-National Institute of Oceanography, Regional Centre, Kochi, India.
Mar Pollut Bull. 2022 Apr;177:113529. doi: 10.1016/j.marpolbul.2022.113529. Epub 2022 Mar 10.
This baseline study on microplastics (MPs) in calanoid copepods in the Kochi backwaters (KBW), India's largest estuary system on the west coast, focuses on (a) the spatiotemporal variations of MPs with the seasonal hydrography setting, and (b) how man-made flow restrictions of a large saltwater barrage contribute to MPs in copepods and their potential to transfer to higher trophic levels. This study found that MPs in copepods in the KBW ranged from av. 0.01 ± 0.014 to 0.11 ± 0.03 no./ind. seasonally. When the saltwater barrage shutters were fully/partially closed during the Pre-monsoon/Northeast Monsoon, MPs in copepods were considerably larger (av. 0.11 ± 0.03 no./ind., and av. 0.075 ± 0.02 no./ind., respectively) as compared to the Southwest Monsoon (av. 0.03 ± 0.01 no./ind.), when the barrage shutters were fully open. This shows the potential of man-made flow restrictions to increase the bioconcentration of MPs in copepods and their possible transfer to higher trophic levels through the food chain, adding to the region's previous discovery that much higher trophic level resources are polluted with a high concentration of MPs.
本研究以印度西海岸最大的河口系统——科奇泻湖（Kochi backwaters，KBW）中的短尾真哲水蚤（Calanus）为对象，对微塑料（MPs）进行了基线研究，重点关注了（a）MPs 随季节性水文学特征的时空变化，以及（b）大型海水堰闸的人为水流限制如何导致 MPs 在真哲水蚤体内蓄积及其向更高营养级转移的潜在风险。本研究发现，KBW 中真哲水蚤体内的 MPs 含量存在季节性变化，范围为 0.01±0.014 至 0.11±0.03 个/只。在前季风期/东北季风期，当海水堰闸完全/部分关闭时，真哲水蚤体内的 MPs 明显增多（分别为 0.11±0.03 个/只和 0.075±0.02 个/只），而在西南季风期（0.03±0.01 个/只）时，堰闸完全开启。这表明人为的水流限制可能会增加 MPs 在真哲水蚤体内的生物浓缩，并可能通过食物链将其转移到更高的营养级，这进一步证实了该地区先前的发现，即更高营养级的资源也受到了高浓度 MPs 的污染。
