Detection of Procambarus clarkii by funnel traps and environmental DNA depends on pond characteristics and crayfish abundances

The presence of Procambarus clarkii was surveyed in a network of 158 ponds in France by using funnel traps and eDNA analyses concomitantly. Ponds were described using 6 habitat variables: perimeter, surface, maximum depth (sometimes estimated), estimated volume, mean shoreline slope and occurrence of litter. Additionally, 5 water quality variables (temperature, turbidity, conductivity, pH and dissolved oxygen) were measured on a subsample of 82 ponds. For the 51 ponds where crayfish were trapped, CPUE (catch per unit effort - number of crayfish per trap per 24h) and the proportion of juveniles were calculated.

本研究通过同步采用漏斗诱捕与环境DNA（eDNA）分析手段，对法国境内由158个池塘组成的调查网络内的克氏原螯虾（Procambarus clarkii）分布情况开展了普查。研究人员针对所有池塘记录了6项生境变量：池塘周长、表面积、最大水深（部分为估算值）、估算容积、岸线平均坡度以及枯落物存在情况。此外，研究人员在82个池塘组成的子样本中测定了5项水质指标：水温、浊度、电导率、pH值与溶解氧含量。针对其中51个成功捕获螯虾的池塘，研究人员计算了单位捕捞努力量渔获量（CPUE，catch per unit effort，即每24小时每台诱捕器的螯虾捕获数）以及幼体占比。