Changes in fisheries discard rates and seabird communities
Changes in fisheries discard rates and seabird communities
复制标题
DOI：
10.1038/nature02315
复制
发表时间：
2004-02-19
期刊：
影响因子：
64.8
通讯作者：
Thompson, DR
中科院分区：
文献类型：
--
作者：
Votier, SC;Furness, RW;Thompson, DR
很明显，商业渔业的丢弃物是世界各地许多海鸟物种的主要食物来源（1 - 8）。但是，预测海鸟群落对丢弃率变化的反应是有问题的，需要历史数据来阐明其他更“自然”的生态过程的混杂影响。在北海，鱼量下降、技术措施改变、种群结构改变（9）以及制定鳕鱼（Gadus morhua）恢复方案（10）将改变被丢弃的鱼的数量。这一区域也是重要的国际海鸟种群的栖息地（11），其中一些海鸟广泛但随意地以丢弃物为食，特别是以小型黑线鳕（Melanogrammus aeglefinus）和鳕鱼（Merlangius merlangus）为食（1 - 3）。在这里，我们使用的长期数据集从北海北方显示，有一个直接的联系之间的丢弃可用性和丢弃使用的通才捕食者和清道夫大贼鸥（贼鸥）。丢弃率的降低，特别是当再加上小型浅水中上层鱼类，如沙笛（Ammodytes marinus）的可用性减少时，导致大贼鸥对其他鸟类的捕食增加。兼性食腐动物对猎物的这种转换对一些海鸟群落构成了潜在的严重威胁。
It is clear that discards from commercial fisheries are a key food resource for many seabird species around the world(1-8). But predicting the response of seabird communities to changes in discard rates is problematic and requires historical data to elucidate the confounding effects of other, more 'natural' ecological processes. In the North Sea, declining stocks, changes in technical measures, changes in population structure(9) and the establishment of a recovery programme for cod (Gadus morhua(10)) will alter the amount of fish discarded. This region also supports internationally important populations of seabirds(11), some of which feed extensively, but facultatively, on discards, in particular on undersized haddock (Melanogrammus aeglefinus) and whiting (Merlangius merlangus)(1-3). Here we use long-term data sets from the northern North Sea to show that there is a direct link between discard availability and discard use by a generalist predator and scavenger-the great skua (Stercorarius skua). Reduced rates of discarding, particularly when coupled with reduced availability of small shoaling pelagic fish such as sandeel (Ammodytes marinus), result in an increase in predation by great skuas on other birds. This switching of prey by a facultative scavenger presents a potentially serious threat to some seabird communities.