Updated life history traits' scoring to calculate a trawl disturbance indicator on mega- epibenthic fauna

particularly suited to the purpose of measuring the sensitivity of benthic communities to trawling, a trawl disturbance indicator (de juan and demestre, 2012, de juan et al. 2009) was proposed based on benthic species life history traits to evaluate the sensibility of mega- and epifaunal community to fishing pressure known to have a physical impact on the seafloor (such as dredging and bottom trawling). the selected biological traits were chosen as they determine vulnerability to trawling: mobility, fragility, position on substrata, average size and feeding mode that can easily be related to the fragility, recoverability and vulnerability ecological concepts. life history traits of species have been defined from the biotic database (marlin, 2014) and from information given by le pape et al. (2007), brindamour et al. (2009) and garcia (2010). for missing life history traits, additional information from literature has been considered.the five categories retained are life history functional traits that were selected based on the knowledge of the response of benthic taxa to trawling disturbance (de juan and demestre, 2012). they reflect respectively the possibility to avoid direct gear impact, to benefit from trawling for feeding, to escape gear, to get caught by the net and to resist trawling/dredging action, each of these characteristics being either advantageous or sensitive to trawling. then, to allow quantitative analysis, a score was assigned to each category: from low vulnerability (0) to high vulnerability (3). the five categories scores were then summed for each taxon (the highly vulnerable taxon could reach the maximum score is 15) and this value may be considered as a species index of sensitivity to trawling disturbance.the scores of 812 taxa commonly found in bottom trawl by-catch in the southern north sea, english channel and north-western mediterranean were described.

特别适用于衡量底栖群落对拖网的敏感性，基于底栖物种的生命史特征，提出了一个拖网干扰指标（De Juan 和 Demestre，2012；De Juan 等人，2009），以评估巨型和无脊椎动物群落对渔业压力的敏感性，这种压力已知会对海底造成物理影响（如疏浚和底拖网）。所选的生物特征被选中，因为它们决定了底拖网的易损性：活动性、脆弱性、在基质上的位置、平均体型和摄食方式，这些特征均易于与脆弱性、恢复力和易损性生态概念相联系。物种的生命史特征已从生物数据库（Marlin，2014）以及来自 Le Pape 等人（2007）、Brindamour 等人（2009）和 Garcia（2010）的信息中定义。对于缺失的生命史特征，考虑了文献中的额外信息。保留的五个类别是基于对底栖类群对拖网干扰响应的知识而选定的生命史功能特征（De Juan 和 Demestre，2012）。它们分别反映了避免直接渔具影响的可能性、从拖网中受益以摄食的可能性、逃避渔具的可能性、被网捕获的可能性以及抵抗拖网/疏浚作用的可能性，每一种特征要么对拖网有利，要么对拖网敏感。随后，为了进行定量分析，每个类别都被分配了一个分数：从低易损性（0）到高易损性（3）。然后，每个类群的五个类别分数被汇总，高度易损的类群可能达到最高分数15分，这个值可被视为物种对拖网干扰敏感性的指标。812个在北海南部、英吉利海峡和西北地中海底部拖网副渔获物中常见的类群的分数已被描述。