Large-Scale Experimental Test of Recruitment Limitation in Marine Fish

该项目将在大空间尺度(直径100‘S的珊瑚礁)和大时间尺度(整整一代人)上，以前所未有的详细程度测试招募限制假说。初步工作表明，世代时间约为3年的双色丹自鱼是进行这项测试的极佳物种，巴哈马利斯托克岛的加勒比海海洋研究中心是理想的研究区域。招募限制假说将通过两种方式进行检验：(1)通过长期监测四个自然经历非常不同的幼虫定居速率的大型珊瑚礁的人口速率，以及(2)通过对这些地点的幼虫定居速率的实验操纵。过去两年的基线人口监测表明，低沉降量的地点--无论是自然的还是实验诱导的--应该证实了这一假设。详细的人口数据将被用来构建基于经验的大小结构开放人口模型。这些模型的弹性分析将确定不同人口比率在驱动当地种群规模变化方面的相对重要性。本研究的观察-实验和经验-理论相结合的方法将为海洋鱼类补充限制假说提供一种新的大规模检验。此外，该项目可能为人类引起的全球气候变化对珊瑚礁的影响提供洞察力。基线人口监测发现，与其栖息的珊瑚漂白和死亡有关的双色柔鱼种群在整个区域三年内呈下降趋势。这个项目将决定这种人口下降是否是一种长期的、多代人的趋势。

This project will test the recruitment limitation hypothesis in unprecedented detail and at both large spatial scales (reefs 100's of meters in diameter) and large temporal scales (an entire generation). Preliminary work has shown that the bicolor damselfish (Stegastes partitus, Pomacentridae), having a generation time of about 3 years, is a superb species for this test, and that the Caribbean Marine Research Center at Lee Stocking Island, Bahamas, is an ideal study area. The recruitment limitation hypothesis will be tested in two ways: (1) by long-term monitoring of demographic rates at four large reefs that naturally undergo vastly different rates of larval settlement, and (2) by experimental manipulations of rates of larval settlement to these sites. Sites with low settlement-either natural or experimentally induced-should corroborate the hypothesis, as suggested by baseline demographic monitoring over the past 2 years. Detailed demographic data will be used to construct empirically based size-structured open-population models. Elasticity analysis of these models will determine the relative importance of different demographic rates in driving changes in local population size.The combined observational-experimental and empirical-theoretical approach of this study will provide a novel large-scale test of the recruitment limitation hypothesis for marine fish. Additionally, this project may provide insight on the effects of human-induced global climate change on coral reefs. Baseline demographic monitoring has detected a region-wide 3-year decline in bicolor damselfish populations correlated with the bleaching and death of the corals they inhabit. This project will determine whether this population decline is a long-term, multi-generation trend.