Minnigiak: Forage fish ecology and population dynamics in northern Labrador under a changing climate

Minnigiak：气候变化下拉布拉多北部的饲料鱼生态和种群动态

• 批准号: RGPIN-2020-05030
• 负责人: Geoffroy, Maxime
• 金额: $ 2.04万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716325
• 关键词: Minnigiak; Forage; fish; ecology; population

Forage fish funnel energy between zooplankton and top predators and represent a key trophic link of marine ecosystems. Capelin (Mallotus villosus), sand lance (Ammodytes spp.) and Arctic cod (Boreogadus saida) are the main forage fish in the Labrador Sea. Variations in the abundance of these three species have cascading impacts on the whole ecosystem, including on fish, seabirds, and marine mammals with high socioeconomic value. Yet, the distribution and population dynamics of forage fish remain major knowledge gaps precluding our understanding of ongoing changes in the marine ecosystems of the region. The northern Labrador shelf is a unique area of the Arctic gateway characterized by very strong interannual and decadal variations in temperature and environmental conditions. These variations modify primary (algae) and secondary (zooplankton) productions, as well as the population dynamics and distribution of forage fish. The alternation between years colder and warmer than average also results in an overlap between boreal (e.g. capelin and sand lance) and Arctic (e.g. Arctic cod) species. The overarching and novel question this research program addresses is: How do short- and long-term variations in environmental conditions drive forage fish population dynamics at the Atlantic-Arctic gateway? Answering this question is critical to predict the resilience of marine ecosystems to changes in environmental conditions as well as to forecast the northern range expansion of boreal fish in the Canadian Arctic. Specific objectives include: (I) Documenting and forecasting changes in the distribution and abundance of capelin, sand lance and Arctic cod in relation to environmental conditions; (II) Measuring the dietary niche overlaps and interspecific competition between boreal and Arctic forage fish; and (III) Identifying the main drivers of capelin recruitment in northern ecosystems. The highly novel components of this program are twofold: First, it will identify the mechanisms driving changes in pelagic ecosystems at the northwest Atlantic-Arctic gateway, which remains a black box in a region at the forefront of global changes. Second, the unique combination of ship-based and moored broadband acoustic echosounders, environmental DNA, and trawls will increase the taxonomic, spatial, and temporal resolution of the forage fish surveys to a level never reached before at the Atlantic-Arctic gateway. In addition to training 5 HQP, this research program will contribute to advancing ecosystem-based management for sustainable commercial and cultural fisheries. Ultimately, it will improve our predictions of the resilience of Arcto-boreal marine ecosystems to climate change.

饲料鱼在浮游动物和顶级捕食者之间输送能量，代表海洋生态系统的关键营养环节。毛鳞鱼 (Mallotus villosus)、沙矛鱼 (Ammodytes spp.) 和北极鳕鱼 (Boreogadus saida) 是拉布拉多海的主要饲料鱼。这三个物种的丰度变化对整个生态系统产生连锁影响，包括具有高社会经济价值的鱼类、海鸟和海洋哺乳动物。然而，饲料鱼的分布和种群动态仍然是主要的知识差距，妨碍我们了解该地区海洋生态系统的持续变化。拉布拉多北部陆架是北极门户的一个独特区域，其特点是温度和环境条件的年际和年代际变化非常强烈。这些变化改变了初级（藻类）和次级（浮游动物）的生产，以及饲料鱼的种群动态和分布。比平均年份更冷和更暖的年份交替也导致北方物种（例如毛鳞鱼和沙矛鱼）和北极物种（例如北极鳕鱼）之间的重叠。该研究计划要解决的首要且新颖的问题是：环境条件的短期和长期变化如何驱动大西洋-北极门户的饲料鱼种群动态？回答这个问题对于预测海洋生态系统对环境条件变化的恢复能力以及预测加拿大北极地区北方鱼类的分布范围至关重要。具体目标包括： (I) 记录和预测毛鳞鱼、沙枪鱼和北极鳕鱼的分布和丰度随环境条件的变化； (II) 测量北方和北极饲料鱼之间的饮食生态位重叠和种间竞争； (III) 确定北方生态系统中毛鳞鱼补充的主要驱动因素。该计划的高度新颖的组成部分有两个：首先，它将确定驱动西北大西洋-北极门户的中上层生态系统变化的机制，该门户仍然是处于全球变化最前沿的地区的一个黑匣子。其次，船载和系泊宽带声学回声测深仪、环境DNA和拖网的独特组合将把饲料鱼调查的分类、空间和时间分辨率提高到大西洋-北极门户以前从未达到的水平。除了培训 5 个 HQP 之外，该研究计划还将有助于推进基于生态系统的可持续商业和养殖渔业管理。最终，它将改善我们对北极寒带海洋生态系统对气候变化的适应能力的预测。