We investigated differences in resource use between two sympatric sea snake species from the west coast of India, Hydrophis curtus and H. schistosus, and described the impacts of fishing on the interactions of these species. We compared habitat use, diet, and isotopic niche width between species to determine resource overlap. We then compared trophic overlap of each species with the fisheries in the region and tested the effect of fishing intensity on their isotopic niche width. Hydrophis curtus used deeper habitats than H. schistosus, resulting in increased spatial overlap with fisheries. The two species also had distinct trophic niches and H. curtus prey formed a larger proportion of fishery catch on average than H. schistosus. This greater overlap could make H. curtus more vulnerable to the effects of fisheries. Both species exhibited expansion in short-term and long-term isotopic niche width along a gradient of fishing intensity which may indicate behavioural changes associated with the presence of fisheries. Hydrophis curtus is a trophic generalist, competes with syntopic species and is dominant in most assemblages. However, H. schistosus exhibits higher plasticity in resource use and may have an advantage over H. curtus. Sea snakes play an important role as mesopredators and as intermediate links in coastal marine food webs. Thus, fishing could alter the relative abundance of these mesopredators with cascading effects through coastal food webs.

我们调查了来自印度西海岸的两种同域海蛇物种Hydrophis curtus和H. schistosus在资源利用方面的差异，并描述了捕鱼对这些物种相互作用的影响。我们比较了物种之间的栖息地使用、饮食和同位素生态位宽度，以确定资源重叠。然后，我们比较了每个物种与该地区渔业的营养重叠，并测试了捕捞强度对其同位素生态位宽度的影响。Hydrophis curtus使用比H. schistosus更深的栖息地，导致与渔业的空间重叠增加。这两个物种也有不同的营养生态位和H. curtus平均而言，猎物占渔业捕捞量的比例高于血吸虫。这种更大的重叠可能使H. curtus更容易受到渔业的影响。两个物种都显示出短期和长期同位素生态位宽度沿着捕捞强度梯度扩大，这可能表明与渔业存在相关的行为变化。Hydrophis curtus是营养多面手，与同种物种竞争，在大多数组合中占优势。然而，H. schistosus在资源利用方面表现出更高的可塑性，可能比H. curtus更具优势. 海蛇作为中食性动物和沿海海洋食物网的中间环节发挥着重要作用。因此，捕鱼可以通过沿海食物网改变这些食肉动物的相对丰度，并产生级联效应。