Fishery managers establish limits on the possession of certain sizes or numbers of sportfish to structure populations and manage for sustainability. However, when the vast majority of fish are released, possession limits become less useful for structuring a population because most fish are released alive. I explored a novel approach of coupling environmental modeling with demography and fishery data to determine if environmental habitat capacity influenced abundance in a fishery subjected to differed levels of total annual mortality. Using RAMAS-GIS (Version 6), I constructed models with data from habitat conditions and twenty years of monitoring (2009–2019) the catch-and-release fishery for Largemouth Bass () in the upper Chesapeake Bay (Maryland, USA). Abundance in the fishery varied with trends in a key environmental indicator of habitat capacity for the fish, submerged aquatic vegetation, and variation in annual mortality (A). Scenarios with average annual mortality levels for the fishery ( = 38 %) had, on average, 8 % greater abundance than scenarios with the highest annual mortality levels observed for a fishery ( = 46 %). The scenario with the highest annual mortality level required a positive environmental trend in habitat capacity in order to support an abundance similar to that for the average annual mortality scenario. Regardless of the trend in habitat carrying capacity, the proportion of fish at or greater than 381 mm in the population decreased from 56 % (no fishery) to 43 % (average fishing mortality) to 35 % (above average fishing mortality), depending on total annual mortality. Model predictions were supportive of that observed for the fishery in that above average levels of annual mortality and catch were sustained at a period with near or above average habitat availability. However, when habitat declined, catch subsequently became more variable and increased following a period of both lower annual mortality and increasing habitat availability. My results indicate that catch-and-release fisheries should be managed by protecting and improving essential habitat conditions, when possible; and if not, then preventing periodically high levels of annual mortality becomes necessary for maintaining consistent abundance.

中文翻译：

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基于 GIS 的捕捞和释放渔业管理方法

渔业管理者对特定大小或数量的运动鱼的拥有量进行限制，以构建种群结构并进行可持续管理。然而，当绝大多数鱼被释放时，占有限制对于构建种群就不再那么有用，因为大多数鱼都是活着释放的。我探索了一种将环境模型与人口统计和渔业数据相结合的新方法，以确定环境栖息地容量是否会影响受不同年度总死亡率水平影响的渔业丰度。我使用 RAMAS-GIS（第 6 版），利用栖息地条件数据和切萨皮克湾上游（美国马里兰州）大口黑鲈捕捞和释放渔业二十年监测（2009-2019 年）的数据构建了模型。渔业丰度随鱼类栖息地容量、沉水水生植被和年死亡率变化等关键环境指标的趋势而变化（A）。渔业年平均死亡率 (= 38%) 的情景比观察到的渔业年死亡率最高的情景 (= 46%) 的丰度平均高出 8%。年死亡率最高的情景需要栖息地容量呈积极的环境趋势，以支持与平均年死亡率情景相似的丰富程度。无论栖息地承载能力的趋势如何，种群中体长或大于 381 毫米的鱼类比例从 56%（无渔业）下降至 43%（平均捕捞死亡率）至 35%（高于平均捕捞死亡率），具体取决于年总死亡率。模型预测支持渔业观察结果，因为在栖息地可用性接近或高于平均水平的时期，年死亡率和渔获量持续高于平均水平。然而，当栖息地减少时，捕获量随后变得更加可变，并且在年死亡率较低和栖息地可用性增加的时期之后增加。我的研究结果表明，应尽可能通过保护和改善基本栖息地条件来管理捕捞和释放渔业；如果不是，那么就必须防止周期性高水平的年度死亡率以维持持续的丰富度。