Quantifying spatial dynamics and stock structure of Atlantic halibut within the Gulf of St. Lawrence to improve sustainable exploitation and management

大西洋大比目鱼（Hippoglossus Hippoglossus）是加拿大大西洋地区单位重量最有价值的底栖鱼。尽管对加拿大5个省具有很高的社会经济重要性，但圣劳伦斯湾（GSL）的种群目前在有限的科学知识下进行管理，使渔业容易受到不断变化的生态系统条件的影响。本研究旨在为改善大西洋大比目鱼的评估和管理提供新的知识。主要目标是通过为设计专门的种群调查提供信息，促进资源的最佳和可持续开发。这将通过五个具体目标来实现：(1)通过对成鱼的卫星标记来评估整个管理单元内深度和温度关联的时空变化；(2)利用基于卫星标签记录的深度和温度日变化的地理定位模型揭示分布和季节迁移模式；(3)确定产卵和摄食活动等关键行为的时间和地点，这些行为对种群评估和调查设计有影响；(4)结合产卵地点、卵龄和幼虫潜伏期的知识，利用循环模型定位潜在的苗圃；(5)利用耳石化学对生命史运动进行量化，评估海湾不同区域之间的连通性。在短期内，该方案的结果将有助于设计一项新的调查，并为改进渔业管理提供基础，包括根据资源丰富程度制定捕捞配额。在中期，该计划将为与生态认证相关的行业未来的选择提供必要的科学信息，这通常可以进入优质市场和更高的土地价值。从长远来看，作为该计划的一部分培养的学生和博士后将在国家一级严重短缺的部门担任重要的学术，政府和行业职位。

Atlantic halibut (Hippoglossus hippoglossus) supports the most valuable groundfish fishery per-unit-weight in Atlantic Canada. Despite high socio-economic importance for 5 Canadian provinces, the stock in the Gulf of St. Lawrence (GSL) is currently managed under limited scientific knowledge, making the fishery vulnerable to changing ecosystem conditions. This research aims to generate new knowledge to improve the assessment and management of GSL Atlantic halibut. The main objective is to facilitate the optimal and sustainable exploitation of the resource by informing the design of a dedicated survey for the stock. This will be achieved through five specific objectives: (1) assess spatio-temporal variability in depth and temperature associations within the whole management unit through satellite tagging of adult fish; (2) reveal distribution and seasonal migration patterns using a geolocation model that relies on daily changes in depth and temperature recorded by satellite tags; (3) identify the timing and location of key behaviours such as spawning and feeding activity, which have implications for stock assessment and survey design; (4) locate potential nursery areas using a circulation model with the combined knowledge of spawning location, and egg and larval incubation period; and (5) assess connectivity among different sectors of the Gulf by quantifying movements through life history using otolith chemistry. In the short term, results from this program will facilitate the design of a new survey and provide a basis for improved management of the fishery including fishing quotas based on abundance of the resource. In the mid-term, the program will provide scientific information necessary for future choices by industry related to eco-certification, which typically gives access to premium markets and higher landed value. In the longer term, the students and postdoctoral fellow trained as part of this program will take key academic, government and industry positions in a sector where a severe shortage has been identified at the national level.