Institut des Sciences de la Mer, Université du Québec à Rimouski, Rimouski, Quebec, Canada.
Northwest Atlantic Fisheries Centre, Fisheries and Oceans Canada, St. John's, Newfoundland, Canada.
J Fish Biol. 2023 Dec;103(6):1430-1444. doi: 10.1111/jfb.15519. Epub 2023 Sep 13.
Greenland halibut (Reinhardtius hippoglossoides) sustain one of the most lucrative fisheries in the eastern Canadian Arctic and Labrador Sea. This species also plays an important role in food web connectivity and benthic-pelagic coupling. Despite the relatively rich knowledge of this species, R. hippoglossoides ecology in these specific areas remains poorly understood. The main aim of this study was to characterize the diet of this deepwater fish in the Labrador Sea and Davis and Hudson Straits and characterize the predator-prey relationship with northern shrimp (Pandalus borealis), another commercially important species in the region. Stomach contents analyses were conducted on 1199 fish captured from 2018 to 2020. Small specimens (<20 cm) fed on invertebrates, whereas larger individuals (>60 cm) fed primarily on fish, indicative of size-related changes in diet composition. The relative abundance of Pandalus shrimp species in the environment was reflected in the diet. Location appeared to be the most influential variable on feeding patterns. Distinct oceanographic conditions among areas, resulting in differences in prey availability, could explain these results. Arctic cod (Boreogadus saida) and redfish (Sebastes sp.) were selected in locations where fish prey were the most abundant. These results shed light on the opportunistic nature of R. hippoglossoides and its preference for fish at large size. With the rapidly changing oceanographic conditions of Arctic waters, a distributional change in the biomass of shrimp is expected. Results suggest that an increase in abundance of predatory groundfish species in the system (e.g., Sebastes sp.) could lead to acute predation on shrimp and competition with R. hippoglossoides. By revealing key trophic links within the demersal ecosystem, this work provides valuable information on the development of ecosystem approaches to fisheries management for the region.
格陵兰比目鱼（Reinhardtius hippoglossoides）是加拿大东部北极和拉布拉多海最赚钱的渔业之一。这种鱼类在食物网连通性和底栖-上层耦合中也起着重要作用。尽管对这种鱼类有相对丰富的了解，但在这些特定地区，R. hippoglossoides 的生态仍然知之甚少。本研究的主要目的是描述拉布拉多海和戴维斯和哈德逊海峡这种深海鱼类的饮食，并描述与另一种该地区具有商业重要性的物种北方虾（Pandalus borealis）之间的捕食者-猎物关系。对 2018 年至 2020 年间捕获的 1199 条鱼进行了胃内容物分析。小标本（<20 厘米）以无脊椎动物为食，而较大的个体（>60 厘米）主要以鱼类为食，表明饮食组成随体型变化而变化。环境中北方虾的相对丰度反映在饮食中。位置似乎是对摄食模式影响最大的变量。由于猎物供应的差异，各地区之间明显的海洋条件可能解释了这些结果。在鱼类猎物最丰富的地区，北极鳕鱼（Boreogadus saida）和红鱼（Sebastes sp.）被选择。这些结果揭示了 R. hippoglossoides 的机会主义性质及其对大型鱼类的偏好。随着北极水域海洋条件的迅速变化，预计虾的生物量会发生分布变化。结果表明，系统中捕食性底层鱼类（如 Sebastes sp.）数量的增加可能导致对虾的急性捕食以及与 R. hippoglossoides 的竞争。通过揭示底栖生态系统内的关键营养联系，这项工作为该地区渔业管理的生态系统方法的发展提供了有价值的信息。
