Abstract Discards is an important issue in fisheries around the world. The spatial management of discards has attracted interest as a potential tool for minimizing the unwanted catch. The aim of the present work was to identify areas with high quantities of bottom trawl discarded catch regarding species subjected to MCRS, in six areas of southern European waters (southern Portuguese waters, Catalan Sea, Ligurian and northern Tyrrhenian Seas, Strait of Sicily, eastern Ionian Sea, and Aegean Sea). Analyses were based on two types of data: (a) the undersized catch of species subjected to MCRS from bottom trawl surveys and (b) the actual discarded catch (including undersized and non-undersized individuals) of species subjected to MCRS from commercial bottom trawling. Geostatistical analysis techniques were applied to the first type of data and Generalized Additive Models using environmental variables were applied to the second one. Subsequently, areas that persistently presented high quantities of discarded catch (i.e., “iDC grounds”) or undersized catch (i.e., “iUC grounds”) were identified and mapped. The “iDC grounds”/“iUC grounds” were located either over the slope or within the continental shelf and over marine plateaus, largely depending on the main target species of each fishery. Next, the overlap of “iDC grounds”/“iUC grounds” with the existing Fisheries Restricted Areas (FRAs) and the proposed Marine Protected Areas (MPAs) was estimated aiming to explore how spatial closures could contribute to the reduction of bottom trawl discarded catch/undersized catch. Certain spatial closures were more effective in the Central Mediterranean and others to the Eastern Mediterranean. The overlapping of existing FRAs with “iDC grounds”/“iUC grounds” did not exceed 24 % in any study area, whereas proposed MPAs, like the CIESM Marine Peace Parks, reached up to 90 % for the same study area.

中文翻译：

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海洋空间封闭作为减少底拖网渔业丢弃物的补充工具：来自南欧水域的例子

摘要 丢弃物是全世界渔业中的一个重要问题。丢弃物的空间管理作为减少不需要的渔获物的潜在工具引起了人们的兴趣。目前工作的目的是在南欧水域（葡萄牙南部水域、加泰罗尼亚海、利古里亚海和北第勒尼安海、西西里海峡、东部海域）的六个区域中确定大量底拖网丢弃渔获物的区域。爱奥尼亚海和爱琴海）。分析基于两种类型的数据：(a) 底拖网调查中受 MCRS 影响的物种的尺寸过小渔获量和 (b) 商业底拖网调查中受 MCRS 影响的物种的实际丢弃渔获量（包括体型过小和非体型过小的个体） . 地统计分析技术应用于第一类数据，使用环境变量的广义加性模型应用于第二类数据。随后，确定并绘制了持续出现大量丢弃渔获物（即“iDC 场地”）或尺寸不足（即“iUC 场地”）的区域。“iDC 场地”/“iUC 场地”位于斜坡上方或大陆架内和海洋高原上方，主要取决于每个渔业的主要目标物种。接下来，估计“iDC 场地”/“iUC 场地”与现有渔业禁区 (FRA) 和拟议海洋保护区 (MPA) 的重叠，旨在探索空间封闭如何有助于减少底拖网丢弃的渔获物/尺寸不足的渔获物。某些空间封闭在地中海中部和东地中海更有效。在任何研究区域中，现有 FRA 与“iDC 场地”/“iUC 场地”的重叠均不超过 24%，而拟议的海洋保护区（如 CIESM 海洋和平公园）在同一研究区域达到了 90%。