The Atlantic rock crab (Cancer irroratus) was first found in Icelandic waters in 2006. Since then, the species has dispersed rapidly and is currently found clockwise from the southwest coast of Iceland to the east, corresponding to >70% of the coastline. Here, we present a monitoring study on this non-indigenous crab species in Iceland from 2007 to 2019. The study shows that the rock crab is now the most abundant brachyuran crab species on soft substrate bottoms in Southwest Iceland, both as adults and planktonic larvae, indicating that it is outcompeting its rival native species, the European green crab (Carcinus maenas) and the spider crab (Hyas araneus). The average size of the rock crab was similar over time (2007–2019), although it fluctuated between years in a pattern similar to that for the green crab, while significant reduction in size was observed for male spider crabs. The rock crab population is still in a growth phase in Icelandic waters, as seen in increasing distributional range, and can be found in densities comparable to the highest reported for the species in its native range in North America.

中文翻译：

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冰岛水域三种短尾蟹（Decapoda）的种群动态：大西洋岩蟹（Cancer irroratus）近期定殖的影响

大西洋岩蟹（Cancer irroratus）于2006年首次在冰岛水域被发现，此后该物种迅速分散，目前从冰岛西南海岸向东顺时针方向发现，对应于>70%的海岸线。在这里，我们介绍了 2007 年至 2019 年冰岛对这种非本土螃蟹物种的监测研究。 该研究表明，岩蟹现在是冰岛西南部软底质底部最丰富的短尾蟹物种，无论是成虫还是浮游幼虫，表明它正在与竞争对手的本地物种欧洲绿蟹 ( Carcinus maenas ) 和蜘蛛蟹 ( Hyas araneus )竞争。）。随着时间的推移（2007-2019 年），岩蟹的平均大小相似，尽管它在年份之间以与绿蟹相似的模式波动，而雄性蜘蛛蟹的大小则显着减小。岩蟹种群在冰岛水域仍处于生长阶段，从分布范围的扩大可以看出，其密度可与北美原生范围内该物种报告的最高值相媲美。