Predation Effects on Survival of Coral-Reef Fish Recruits

珊瑚礁鱼类以当地种群的形式出现，占据了一小块栖息地。这些种群构成了海洋生物最丰富的物种组合之一的基础，数百种物种在当地共存。我们对限制种群规模的生态过程的了解很少，而且历史上一直偏重于竞争的研究，以及最近的招募（浮游生物幼虫定居后幼鱼出现在珊瑚礁上的过程）。由于各种各样的物流约束，其他过程尚未得到深入的研究。捕食尤其如此，在其他海洋、淡水和陆地群落中，捕食被证明是一个极其重要的过程。Hixon博士将研究捕食限制了当地珊瑚礁鱼类种群规模这一假设的两个推论：(1)在移除常驻和/或临时食鱼鱼类的珊瑚礁上，新定居的鱼类的存活率将得到提高；(2)这些对存活的影响会随着招募的大小而变化。这些将通过在两个地点的孤立的小块珊瑚礁上对掠食性鱼类进行有控制的实验操作来进行测试：巴哈马的Lee Stocking岛和美属维尔京群岛的圣托马斯岛。

Coral reef fishes occur as local populations occupying patches of habitat. These populations comprise the basis of one of the most speciose assemblages of marine organisms, with hundreds of species coexisting locally. Our knowledge of the ecolgical processes that limit population size is scant and historically has been biased toward studies of competition, and more recently, recruitment (the process of young fish appearing on a reef following settlement of planktonic larvae). Due to a variety of logistic constraints, other processes have not been thoroughly studied. This is especially true of predation, which has been demonstrated to be an extremely important process in other marine, freshwater, and terrestrial communities. Dr. Hixon will investigate two corollaries of the hypothesis that predation limits local population sizes in reef-fishes: (1) survivorship of newly settled fish will be enhanced on reefs where resident and/or transient piscivorous fish are removed; and (2) these effects on survivorship will vary with the magnitude of recruitment. These will be tested by controlled experimental manipulations of predatory fish on isolated patch reefs at two sites: Lee Stocking Island in the Bahamas, and St. Thomas in the U. S. Virgin Islands.