Abstract

The paper presents the results from a study of the population structure of alien snow crabs Chionoecetes opilio in the western Kara Sea near the Kara Strait using two methods: Sigsby trawling and video surveillance. The towed unmanned underwater vehicle Videomodule was used to estimate the population density of crabs: 0.55 ind/m² in 2016, and 0.17 and 0.09 ind/m² in 2017. No differences were revealed when comparing the size structure of the crab population based on the two methods. An exception is possible underestimation of younglings with a carapace width <20 mm when using the Videomodule. The minimum observed carapace size was ~10 mm, and the maximum, 127 mm. Both methods revealed the presence of all stages of crab growth, which indicates successful survival and growth of this crab in the western Kara Sea. An adequate assessment of the development of invasion of alien C. opilio in the Kara Sea requires annual video observations in the regions representing characteristic biotopes at different distances from the Kara Strait.

中文翻译：

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卡拉海外来雪蟹（Chionoecetes opilio）的种群结构（拖网和视频采样）

摘要

本文介绍了通过两种方法对西卡拉海附近卡拉海西部外来雪蟹中华绒螯蟹的种群结构进行研究的结果：Sigsby拖网捕捞和视频监视。拖曳式无人水下航行器视频模块用于估算螃蟹的种群密度：2016年为0.55 ind / m ²，以及0.17和0.09 ind / m ²在2017年。比较基于两种方法的蟹种群的大小结构时，没有发现差异。使用Videomodule时，甲壳宽度<20 mm的幼鱼可能会被低估。观察到的最小甲壳大小约为10毫米，最大为127毫米。两种方法都揭示了蟹类生长的所有阶段，这表明该蟹在卡拉海西部成功地生存和生长。要对卡拉海外来梭状芽胞杆菌入侵的发展进行充分评估，需要每年在代表距卡拉海峡不同距离的典型生物群落区域进行视频观察。