大洋中捕食者的“藏身之所”｜《自然-通讯》

论文标题：Pelagicfish predation is stronger at temperate latitudes than near the equator

期刊：Nature Communications

作者：MariusRoesti, DanielN. Anstett et.al

发表时间：2020/03/31

数字识别码：10.1038/s41467-020-15335-4

《自然-通讯》发表的一篇论文Pelagic fish predation isstronger at temperate latitudes than near the equator指出，鲨鱼、金枪鱼、旗鱼、马林鱼这类大宗鱼类在温带地区海洋的捕食行为比在赤道附近更多。研究结果挑战了之前的假设，即认为赤道附近的捕食行为最多，且捕食行为与鱼类物种多样性呈正相关。

越接近赤道，陆地和海洋的生物多样性常常也更高。不过，对陆地生态系统的研究发现，关于种间作用在赤道附近最强的证据并不一致。同时，我们对于大洋中种间作用的地理差异也了解得不多。

根据中上层延绳钓数据，大洋中顶级鱼类捕食者相对捕食行为的纬度变化。

图片来源：Roesti, M., Anstett, D.N., Freeman, B.G. 等

瑞士伯尔尼大学的Marius Roesti和同事分析了1960年至2014年的中上层（大洋）延绳钓数据集，数据集记录了大宗鱼类捕食者对带饵绳的逾9亿次攻击。他们发现，温带地区（大致在南北纬30度-60度之间的中纬度带）的捕食者攻击比赤道周围更频繁，且这种模式不随时间改变，在四个洋盆中均一致。中上层鱼类的捕食行为在靠近两极处再次减少，而两极的捕食者主要是海洋哺乳动物、海鸟和深海鱼类。

研究还发现，捕食者攻击与大洋鱼类的物种数量呈负相关。这些结果或有助于解释最近的研究发现，即海洋鱼类的物种形成率（新的不同物种的形成）在远离赤道处会增加，因为此前有研究指出，种间作用可以促进物种形成。

摘要：Species interactions are widely thought to be strongest inthe tropics, potentially contributing to the greater number of species at lowerlatitudes. Yet, empirical tests of this “biotic interactions” hypothesis remain limited and often provide mixed results.Here, we analyze 55 years of catch per unit effort data from pelagic longlinefisheries to estimate the strength of predation exerted by large predatory fishin the world’s oceans. We test two central tenets ofthe biotic interactions hypothesis: that predation is (1) strongest near theequator, and (2) positively correlated with species richness. Counter to thesepredictions, we find that predation is (1) strongest in or near the temperatezone and (2) negatively correlated with oceanic fish species richness. Thesepatterns suggest that, at leastfor pelagic fish predation, commonassumptions about the latitudinal distribution of species interactions do notapply, thereby challenging a leading explanation for the latitudinal gradientin species diversity.