Fisheries using bottom trawls are the most widespread source of anthropogenic physical disturbance to seafloor habitats. To mitigate such disturbances, the development of fisheries-, conservation-, and ecosystem-based management strategies requires the assessment of the impact of bottom trawling on the state of benthic biota. We explore a quantitative and mechanistic framework to assess trawling impact. Pressure and impact indicators that provide a continuous pressure–response curve are estimated at a spatial resolution of 1 × 1 min latitude and longitude (∼2 km²) using three methods: L1 estimates the proportion of the community with a life span exceeding the time interval between trawling events; L2 estimates the decrease in median longevity in response to trawling; and population dynamic (PD) estimates the decrease in biomass in response to trawling and the recovery time. Although impact scores are correlated, PD has the best performance over a broad range of trawling intensities. Using the framework in a trawling impact assessment of ten métiers in the North Sea shows that muddy habitats are impacted the most and coarse habitats are impacted the least. Otter trawling for crustaceans has the highest impact, followed by otter trawling for demersal fish and beam trawling for flatfish and flyshooting. Beam trawling for brown shrimps, otter trawling for industrial fish, and dredging for molluscs have the lowest impact. Trawling is highly aggregated in core fishing grounds where the status of the seafloor is low but the catch per unit of effort (CPUE) per unit of impact is high, in contrast to peripheral grounds, where CPUE per unit of impact is low.

中文翻译：

---

不同的底拖网渔业对北海海底生境的状况有不同的影响

使用底拖网进行的渔业是对海底生境的人为物理干扰的最广泛来源。为了减轻这种干扰，渔业，保护和基于生态系统的管理战略的发展需要评估底拖网对底栖生物区系的影响。我们探索定量和机械的框架来评估拖网渔船的影响。可以使用三种方法以1×1分钟的经纬度（〜2 km ²）的空间分辨率估算提供连续压力响应曲线的压力和冲击指标：L 1估算寿命超过社区寿命的社区比例。拖网事件之间的时间间隔；大号2估计拖网造成的中位数寿命下降；人口动态（PD）估计拖网和恢复时间会导致生物量减少。尽管影响得分是相关的，但PD在各种拖网强度下均具有最佳性能。使用该框架对北海十个山脉进行的拖网影响评估显示，泥泞的栖息地受到的影响最大，粗糙的栖息地受到的影响最小。甲壳类的水獭拖网影响最大，其次是沉水鱼类的水獭拖网和比目鱼和蝇类的束拖网捕鱼。束流拖网捕捞棕色虾，水獭拖网捕捞工业鱼类和挖泥软体动物的影响最小。