Assessing connectivity patterns among management units of the Newfoundland and Labrador shrimp population
Assessing connectivity patterns among management units of the Newfoundland and Labrador shrimp population
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DOI：
10.1111/fog.12401
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发表时间：
2019-03-01
影响因子：
2.6
通讯作者：
Snelgrove, Paul V. R.
中科院分区：
文献类型：
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作者：
Le Corre, Nicolas;Pepin, Pierre;Snelgrove, Paul V. R.
作为该地区最重要的渔业之一，加拿大东部北部虾的种群数量自2000年代中期以来急剧下降，至2017年的历史低点，但变化在空间上并不均匀。在纽芬兰和拉布拉多（NL）管理区内，应用生物物理模型，研究了北方熊猫幼体在长海洋阶段（2-3个月）的连系过程，以及不同环境条件下北方熊猫幼体扩散的关键驱动因素。选取具有代表性的3年北大西洋涛动（North Atlantic Oscillation， NAO）对比期，对NL北部对虾种群的潜在扩散模式进行了评估，并分层评估了放生时间（每年和每天）、放生地点和垂直迁移行为对对虾幼虫扩散的影响。总的来说，我们发现，由于拉布拉多洋流占主导地位，位于纽芬兰和拉布拉多大陆架北部的种群为南部种群提供了潜在的定居者。NAO正值年的海洋环流和洋流速度与其他年份不同，形成了不同的沉降空间格局。幼虫释放位置和垂直迁移行为是影响幼虫供应强度和沉降模式的两个最重要因素。无论研究年限如何，包括死亡和个体性游泳行为都增加了从近海地区释放的幼虫的定居成功率。本研究提高了对北方对虾种群补充关系、对环境条件变化的敏感性以及具有长幼虫期的底栖-中上层物种种群数量下降的空间非均匀性的认识，为改进管理策略提供了潜在的帮助。
The Eastern Canadian northern shrimp population, representing one of the most important fisheries in the region, decreased dramatically since the mid-2000s to a historical low in 2017, but changes were not spatially uniform. Applying a biophysical model within Newfoundland and Labrador (NL) management areas, we investigated connectivity processes during the long pelagic larval phase (2-3 months) of Pandalus borealis and key drivers of larval dispersal in different environmental conditions. We selected 3 years representative of contrasting North Atlantic Oscillation (NAO) phases to assess potential larval dispersal patterns of the northern shrimp population in NL, and hierarchically assessed the impact of the timing of release (yearly and daily), release location, and vertical migration behaviour on shrimp larval dispersal. Overall, we found that populations located on the northern Newfoundland and Labrador shelf supplied potential settlers to southern populations because of the dominant Labrador Current. Ocean circulation and current velocities during the NAO positive year differed from other years, generating contrasting settlement spatial patterns. Larval release location and vertical migration behaviour were the two most important influences on the strength of larval supply and settlement patterns. Inclusion of diel and ontogenic swimming behaviour increased settlement success of larvae released from inshore areas, regardless of study years. Our study improves understanding of northern shrimp stock-recruitment relationships, their sensitivity to changing environmental conditions, and spatially non-homogeneous population decline for bentho-pelagic species with a long larval phase, which could potentially help improve management strategies.