拖网对海底环境压力评价方法分析

Analysis of Environment Pressure Assessment Method for Bottom Trawling

底拖网捕捞是最有效的捕捞作业方式之一,但一些学者和渔业管理人员已经观察到其对海底环境影响的严重性和持久性。声纳、视频、遥感、渔船监控系统等技术可以应用于拖网对海底环境压力评价,声纳与视频辅助可以从微观角度评价拖网对海底沉积物影响,遥感影像可以用拖网轨迹宽度、长度量化评价,渔船监控系统可以用累计距离、累计功率距离等参数量化评价。声纳与视频适合小范围,遥感适合大范围评价,但两者在水体浑浊的情况下都不适用,渔船监控系统时空分辨率都较高,可以很好地应用于拖网对海底环境压力评价。

Bottom trawling is one of the most effective fishing methods. But some scholars and fishery managers have observed the seriousness and persistence of its impact on the seabed environment. Sonar, video, remote sensing, fishing vessel monitoring system and other technologies can be used to evaluate the bottom environmental pressure of trawl. Sonar and video can be used to evaluate the impact of trawl on the bottom sediment from a microscopic perspective. Width and length of trawl trajectory can be quantitatively used to evaluate the affection by remote sensing images. Accumulated distance and accumulated power distance can be used to evaluate the affection by fishing vessel monitoring system. Sonar and video are suitable for small area. Remote sensing is suitable for large area evaluation. But both of them are not applicable in the case of turbid water. The space-time resolution of fishing vessel monitoring system is high, which can be well applied to the evaluation of bottom environmental pressure by trawl.