In the southern Gulf of St. Lawrence (sGSL), there is a mostly supplementary fishery for sea scallops (Placopecten magellanicus) concentrated on three primary scallop beds in the Northumberland Strait. The fishery is not subject to an enforced minimum size limit and small scallops (<90 mm shell height) are often removed from this population before they have had time to adequately contribute to population recruitment, resulting in sub-optimal fishery yields and a partially size-suppressed population. This study aimed to provide stakeholders with information related to gear configuration changes that could potentially reduce catches of small scallops in the sGSL fishery by quantifying size-selectivity of different ring sizes (82.6 mm and 88.9 mm) and washer types (rubber and steel). We also compared the catches of small, fecund scallops (45–90 mm) across the different gear configurations. The gears with 82.6 mm rings had high retention of small scallops, with lengths of 50 % retention estimated to be 72.8 and 76.0 mm with rubber and steel washers, respectively. This increased to 87.9 mm and 95.5 mm, respectively, in the gears with 88.9 mm rings. It was estimated that with rubber washers, increasing ring size from 82.6 mm to 88.9 mm will reduce catch of small fecund scallops by 51 %, while reducing catch of large scallops by 27 %. Increasing ring size was more effective than changing washer type at increasing size selectivity of the gear. Previous research on scallop life history suggests that this reduction of large scallops will be temporary because the larger gear will ultimately shift the population size distribution towards larger scallops resulting in higher yield-per-recruit. These results will be useful to resource managers and stakeholders for stock assessments, and for future gear type decisions.

在圣劳伦斯湾南部 (sGSL)，主要是对海扇贝 ( Placopecten magellanicus) 的补充渔业) 集中在诺森伯兰海峡的三个主要扇贝床。渔业不受强制的最小尺寸限制，小扇贝（<90 毫米壳高）经常在它们有时间充分促进种群补充之前从该种群中移除，导致次优渔业产量和部分尺寸- 受压制的人口。本研究旨在通过量化不同环尺寸（82.6 毫米和 88.9 毫米）和垫圈类型（橡胶和钢）的尺寸选择性，为利益相关者提供与渔具配置变化相关的信息，这些信息可能会减少 sGSL 渔业中小扇贝的捕获量。我们还比较了不同齿轮配置的小而肥沃的扇贝（45-90 毫米）的捕获量。82.6 毫米齿圈的齿轮对小扇贝的保留率高，50 % 保留的长度估计分别为 72.8 和 76.0 毫米，橡胶和钢垫圈。在具有 88.9 毫米环的齿轮中，这分别增加到 87.9 毫米和 95.5 毫米。据估计，使用橡胶垫圈，将环尺寸从 82.6 毫米增加到 88.9 毫米将使小扇贝的捕获量减少 51%，同时将大扇贝的捕获量减少 27%。在增加齿轮的尺寸选择性方面，增加环尺寸比改变垫圈类型更有效。先前关于扇贝生活史的研究表明，大扇贝的这种减少将是暂时的，因为更大的齿轮最终会将种群规模分布转向更大的扇贝，从而导致更高的单产。这些结果将有助于资源管理者和利益相关者进行种群评估，