东北大西洋海洋捕捞渔获物营养级变化研究

Changes in trophic level of marine catches in the northeast Atlantic

东北大西洋是重要的海洋捕捞海域,该海域渔业栖息环境易受北极气候变化的影响。为此,本文基于1950-2012年东北大西洋FAO的渔获统计数据,对已开发的293种渔获物平均营养级(mTL)、营养级平衡指标(FIB)和渔获营养级分类(TrC)进行时间序列的统计,为进一步研究该海域渔业资源受北极气候变化的影响提供基础。研究认为,平均营养级(mTL)从1950年(mTL=3.71)下降至2012年(mTL=3.57),每年下降约0.02 TL(r=-0.614;P<0.01),而近8年来营养级平衡指数持续下降。同时,研究表明,东北大西洋渔获物平均营养级和气候变化(海表温上升、北大西洋涛动和海冰缩减等)息息相关,其中渔获量出现高产值均在海表温异常年份:1956年、1976年和1997年。本文分析了东北大西洋渔获物营养级变动情况,为研究东北大西洋渔获组成变化与气候变化的关系提供研究基础,也为渔业资源的可持续开发提供了理论依据。

The northeast Atlantic is said to be an important piece of waters for marine capture. Its inhabiting envi- ronment is sensitive to the changes of the Arctic climate. Based on the data of the catch of FAO in the northeast Atlantic from 1950 to 2012 ,this article analyzes three indexes of 293 exploited marine communities. The three in- dexes are mTL （the temporal trend in the mean trophic level）, FIB （fisheries-in-balance index）, TrC （trophic cate- gories）. The goal is to provide the basis for further study of how the Arctic climate change influences its fishery re- sources. According to our research, the mTL had greatly decreased at a rate of 0.02TL per year （r=-0. 614;P〈 0.01） ,from 3.71 （1950） to 3.57（2012）. Meanwhile,the FIB index had been speeding downhill for the last 8 years. Moreover, the mTL of the catch in the northeast Atlantic is highly related to the climate change （such as rise of sea surface temperature, North Atlantic Oscillation and shrinking sea ice and so on）. It is obvious that high cat- ches came up in the anomalies year of the sea surface temperature： 1956,1976 and 1997. This paper analyzes chan- ges of trophic level to catch in the northeast Atlantic, so as to provide the basis of studying the relationship between fish composition and climate change in the northeast Atlantic. In addition,it also offers a theoretical basis for the sustainable development of fisheries resources.