Catch efficiency is an important index to relate observed density to the size of a population in the context of bottom trawl surveys. The estimation of catch efficiency is challenging because it involves independent measures of animals in the path of the bottom trawl. We estimated catch efficiency using an underwater camera system on three trawl fishing vessels used for estimating the density of the yellow squat lobster (Cervimunida johni) off central Chile. During 2015 and 2018, 54 hauls were analyzed, and a total of 20 h of filming were recorded. A total of 4,155 yellow squat lobster individuals were analyzed approaching the net in the path of the trawl, of which 2,330 (56%) were captured and 1,825 escaped underneath the groundrope. The median estimated ranges of catch efficiency varied between 0.81–0.90 for vessel 1, 0.15–0.72 for vessel 2 and 0–0.58 for vessel 3. According to a hierarchical generalized linear model (HGML), fishing vessels and mean depth of hauls showed significant differences in catch efficiency (p<0.05). The results were comparable with estimates available for other crustacean species, and differences among vessels can be associated with differences in rigging configurations. Discussion was focused on the processes affecting catch efficiency and how differential catchability among sampling vessels may bias the construction of spatially explicit density maps and further abundance estimates of yellow squat lobsters in Chile.

在底拖网调查的背景下，捕捞效率是将观察到的密度与种群规模联系起来的重要指标。捕捞效率的估算具有挑战性，因为它涉及对底拖网路径中的动物进行独立测量。我们在三个拖网渔船上使用水下摄像头系统估算了捕捞效率，这些拖网渔船用于估算黄矮龙虾的密度（Cervimunida johni）在智​​利中部。在2015年和2018年期间，对54部影片进行了分析，并记录了20个小时的拍摄时间。在拖网的路径中，总共分析了4,155个黄矮龙虾个体接近网，其中2,330（56％）被捕获，并且1,825人逃脱了在地下的绳网。渔船1的捕捞效率中值估计范围在0.81–0.90之间，渔船2在0.15–0.72之间，渔船3在0–0.58之间。根据分层广义线性模型（HGML），渔船和平均拖船深度显示出显着性捕捞效率差异（p <0.05）。结果与其他甲壳类物种的估计值可比，船只之间的差异可能与索具配置的差异有关。