Advancing fisheries analysis through the application of ecological foraging principles

通过应用生态觅食原理推进渔业分析

• 批准号: RGPIN-2014-04135
• 负责人: Gillis, Darren
• 金额: $ 1.68万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610850
• 关键词: Advancing; fisheries; analysis; through; application

In public opinion, the health of a fishery is usually equated to maintaining or even increasing catches. However, experiences with Canadian herring and cod in past decades have shown us that this is not always true. The underlying fish populations that sustain our harvests are not always well reflected by the fish that are caught. Fisheries science has shown us many examples where populations “collapse” because sustained periods of decline were not detected quickly enough. One of the less studied influences that can mask population decline is the nature of fishing itself. Our commercial fish harvesters are very good at what they do. As a result, their catches (and catch rates) often remain high, even as fish numbers initially decline. Yet information from commercial fisheries is still the foundation of many of our population estimates. The proposed program questions many of the perspectives of classical fisheries analysis. Traditional analyses define catch rate in terms of the amount of fishing activity: catch per unit effort (CPUE). However, including effort in the measure of performance can mask catches that do not increase in proportion to effort. We will test for these effects with statistical methods looking at effects within entire fleets and at the level of individual vessels. Traditional analyses also assume that the CPUE of the intended species (the target) is the best indicator of changing abundances. However, this is the time when changes in CPUE should be buffered by fisher behaviour. My students and I will test the effectiveness of CPUE from outside of targeting periods in population estimates. The implications of fisher movement between neighboring populations are seldom considered in classical analyses. We will employ a recent theoretical development in our lab that unites ecological foraging principles to fishing activities : fisheries isodars. This will incorporate vessel movements into fishery assessments among neighboring population components and along the boundaries between them. All of these behavioural biases will be used to change the way that effort is used in state-of-the-art population assessment models. Finally, we will test for and simulate changing associations among vessels at sea (networks within fleets) in relation to the underlying fish distributions. This will lay the foundation for the future incorporation of changing fleet structure in population estimates. The proposed research program will transform the use of fishing effort in stock assessments. The research will provide a dynamic perspective of fishing effort that will improve the accuracy of fish population estimates and reduce the risk of misinterpretation of CPUE data that has contributed to fishery crises in the past.

在舆论中，渔业的健康通常等同于保持甚至增加渔获量。然而，过去几十年加拿大鲱鱼和鳕鱼的经验告诉我们，这并不总是正确的。维持我们收成的潜在鱼类种群并不总是被捕捞的鱼很好地反映出来。渔业科学向我们展示了许多种群“崩溃”的例子，因为没有足够快地发现持续的衰退期。能够掩盖种群数量下降的较少研究的影响之一是渔业本身的性质。我们的商业鱼类收割机在这方面做得很好。因此，他们的渔获量(和捕获率)经常保持在较高水平，即使鱼的数量最初有所下降。然而，来自商业渔业的信息仍然是我们许多人口估计的基础。 拟议中的计划对经典渔业分析的许多观点提出了质疑。传统的分析以捕捞活动的数量来定义捕捞率：单位捕捞努力渔获量(CPUE)。然而，将努力包括在绩效衡量中可能会掩盖与努力不成比例增加的渔获量。我们将用统计方法测试这些影响，着眼于整个舰队和单个船只的影响。传统的分析还假定，预期物种(目标)的CPUE是变化丰度的最佳指标。然而，这是CPUE的变化应该被费舍尔行为缓冲的时候。我和我的学生将在人口估计的目标期之外测试CPUE的有效性。在经典分析中，很少考虑相邻种群之间的Fisher运动的含义。我们将在我们的实验室采用一种最新的理论发展，将生态觅食原理与捕鱼活动相结合：渔业等剂量线。这将把船只移动纳入邻近种群组成部分之间以及它们之间边界的渔业评估中。所有这些行为偏差将被用来改变这一努力在最先进的人口评估模型中的使用方式。最后，我们将测试和模拟海上船只(船队内的网络)之间与潜在鱼类分布相关的变化关联。这将为今后将不断变化的船队结构纳入人口估计奠定基础。 拟议的研究计划将改变在种群评估中使用捕捞努力的方式。这项研究将提供捕捞努力的动态视角，以提高鱼类数量估计的准确性，并减少误解CPUE数据的风险，因为这在过去曾导致渔业危机。