长山群岛海洋渔业资源的平均营养级变化特征

Characteristics of variation in mean trophic level of marine fishery resources in Changshan Archipelago

根据长山群岛1965-2016年渔业统计资料,分析长山群岛海域主要捕捞渔获物产量、平均营养级(Mean trophic level,MTL)、渔业均衡指数(Fishing in balance index,FiB)年际变化,探讨其海洋渔业资源利用状况,并利用小波分析方法研究52年来渔获物MTL周期变化特征。研究表明:(1)长山群岛捕捞产量、MTL和FiB指数呈阶段性变化;(2)长山群岛渔业资源开发经历初期开发、扩张捕捞、过度捕捞、资源破坏等四个阶段,渔业资源环境正在逐渐恶化;(3)受人类捕捞活动影响,MTL在15～19年和24～34年两种时间尺度下呈周期波动,30年为第一主周期,17年为第二主周期。长山群岛渔业资源破坏日益严重,未来几年平均营养级将呈下降趋势。为防止渔业资源进一步衰退,应加强捕捞活动管理力度,落实海洋渔业资源保护制度;完善预警机制,构建海洋渔业资源监测系统;同时应积极调整长山群岛渔业产业结构,提高资源产出效率。

This study analyzed the interannual variation in the catch,mean trophic level (MTL) and fishing in balance index (FiB) of captured species, discussed the utilization of marine fishery resources in the waters of the Changshan Archipelago using its fishery statistics from 1965 to 2016. The Periodic variation characteristics of the MTL of catches during the past 52 years were studied by wavelet analysis method. The results showed that:(1) the catch, MTL and FiB of the Changshan Archipelago changed at different stages.(2) The exploitation of fishery resources has gone through four stages: initial exploitation, expansionary fishing, overfishing and resource destruction, and the resources and environment are getting worse.(3) Affected by human fishing activities, the MTL of catch fluctuates periodically at 15 ?19 years and 24 ?34 years of time scales which 30 years is the first main period and 17 years is the second main period. At present, the damage of fishery resources in Changshan Archipelago is becoming more and more serious, and the MTL will decline over the next few years. In order to prevent further decline of fishery resources, the government should strengthen management of fishing activities and implement marine fishery resources protection system. The early warning mechanism and the monitoring system of marine fishery resources should be constructed and improved. At the same time, the fishery industry structure of the Changshan Archipelago should be adjusted actively to improve the efficiency of resource output.