From genes to ecosystems: an eco-evolutionary assessment of alternative harvesting strategies and consequences for fisheries productivity

我们将采用一种新的，多学科的方法来评估在何种程度上生态进化的变化所产生的共同收获的方法影响渔业生产力。我们将融合新兴的理论，概念和人口基因组学，生态进化动力学和社区生态学的新进展进行大规模的收获选择实验的基础上实验控制消耗在一系列封闭的，自然的鳟鱼种群。我们的项目将利用加拿大公园管理局的授权，积极恢复以前无鱼的高山湖泊，80-100年前引入了非本地鳟鱼。因此，它提供了一个特殊的机会，进行复制消耗自然种群的社会经济重要的鱼类种群（鲑鱼），他们将被删除无论如何。这些消耗将被用来（一）探讨几个未经检验的假设的大小选择性捕捞渔业生产力和生态系统功能的影响，（二）表征的有效性的替代捕捞方法，大大减少大小选择性的影响（“平衡捕捞”）。同时，该项目将有助于实现生态系统的恢复目标，使用非毒物清除技术，为加拿大最重要的遗产象征之一-壮丽的落基山脉湖泊。鳟鱼耗竭将模拟（i）通常发生的大型个体的大小选择性收获（4个湖泊）和（ii）“平衡收获”，其中死亡率分布在生态系统中最大范围的大小，与其自然生产力成比例，目的是最大限度地减少大小选择性和相关的进化变化（4个湖泊）; 4个额外的非耗竭湖泊将作为对照。自2011年以来，在第13个湖泊中进行了密集的大小选择性收获，并对与收获选择性相关的基因组变化进行了长期的时间评估。湖泊将具有类似的特点，并有一个可以忽略不计的历史捕鱼之前，鳟鱼枯竭。将连续几年对多个年龄组在基因、人口、社区和生态系统各级进行一系列反应变量/指标的消耗前和消耗后监测。

We will employ a novel, multidisciplinary approach to assess to what degree eco-evolutionary changes generated by common harvesting approaches affect fisheries productivity. We will blend emerging theory, concepts and new advances in population genomics, eco-evolutionary dynamics and community ecology to conduct a large scale harvest selection experiment based on experimentally-controlled depletions across a series of closed, natural trout populations. Our project will take advantage of the mandate of Parks Canada to actively restore previously fishless alpine lakes where non-native trout were introduced 80-100 years ago. Hence it provides an exceptional opportunity to conduct replicated depletion of natural populations of a socio-economically important fish species groups (salmonids) where they will be removed anyways. These depletions will be used to (i) explore several untested hypotheses about the effects of size-selective harvesting on fisheries productivity and ecosystem function and (ii) characterize the efficacy of an alternative harvesting approach to substantially reduce size-selective effects ('balanced harvesting'). Concurrently, the project will contribute to reaching ecosystem restoration targets using non-poison removal techniques, for one of Canada's most important heritage symbols - the magnificent Rocky Mountain lakes. Trout depletion will simulate (i) commonly occurring size-selective harvesting of large-sized individuals (4 lakes) and (ii) 'balanced harvesting', wherein mortality is distributed across the widest range of sizes in an ecosystem, in proportion to their natural productivity, with the aim that size-selectivity and associated evolutionary changes are minimized (4 lakes); 4 additional, non-depleted lakes will act as controls. Intense size-selective harvesting has taken place in a 13th lake since 2011 and affords a longer-term temporal assessment of genomic change associated with harvesting selectivity. Lakes will be of a similar characteristics and have had a negligible history of fishing prior to trout depletion. Pre- and post-depletion monitoring of a series of response variables/metrics at the gene, population, community and ecosystem levels will be conducted on multiple age-cohorts over successive years.