Impact of Larval Transport and Benthic Habitat Quality upon Recruitment Dynamics: Poor Nursery Habitat Decouples Larval Supply from Reproductive Output of Caribbean Spiny Lobster

这项研究是基于先前对加勒比海刺龙虾的补充研究，建立在集合种群和源汇动力学的理论框架下，在巴哈马埃克苏马湾的四个分布广泛的地点(超过100‘S)。这些发现基于野外采样、野外实验和物理运输的二维水动力模型，产生了一个概念模型，描述了物理运输、栖息地质量和成体丰度对刺龙虾补充的集体影响。具体地说，四个地点的幼虫和成虫丰度的空间格局在三年内是一致的，成虫丰度和成虫丰度在空间上是分离的，幼虫和幼虫通过涡流和地转流进行的运输在很大程度上解释了幼虫和幼虫的空间格局(中尺度变化的67%)。这表明栖息地质量和物理运输在空间上分离了补充和成虫丰度，从而产生了一个源-汇网络。这些调查结果对于了解招募过程和安置海洋保护区以加强招募具有重大意义。特别是，在通过基本的水动力过程直接和强有力地控制幼虫供应以及在海洋保护区设计方面的适用性方面，这些结果是新颖的。例如，将海洋保护区置于水槽栖息地将导致一种错误的安全感，并不能防止被严重开发的种群在当地灭绝。这项调查检验了从早期发现得出的一个关键假说：一些地点糟糕的栖息地质量不成比例地降低了新兵的存活率，从而使幼虫供应和随后的成虫丰度脱钩。它包括测量和操纵实验，特别是为了测量栖息地和苗圃栖息地的绝对可用性，量化定居后和幼年刺龙虾的丰度和存活率，以及量化四个地点的种群参数。因此，这项研究是对自然运输、栖息地质量和成体丰度对海洋物种补充动态的集体影响的独特经验检验。

This study is based on prior research of recruitment in the Caribbean spiny lobster, couched in the theoretical framework of metapopulation and source?sink dynamics, at four widely spaced sites (over 100's of kms) in Exuma Sound,Bahamas. Those findings, which were based on field sampling, field experiments and a 2?D hydrodynamic model of physical transport, produced a conceptual model describing the collective influence of physical transport, habitat quality and adult abundance upon spiny lobster recruitment. Specifically, spatial patterns in recruitment and adult abundance across the four sites were consistent over three years, adult abundance and recruitment were decoupled spatially, and the spatial patterns in recruitment were explained largely (? 67 % of mesoscale variation) by larval and postlarval transport via gyral currents and geostrophic flow. These suggested that habitat quality and physical transport decoupled recruitment and adult abundance spatially, thereby producing a source?sink network. These findings have major implications for understanding of recruitment processes and placement of marine reserves to enhance recruitment. In particular, the results are novel in their demonstration of direct and strong control of larval supply by fundamental hydrodynamic processes, and in their applicability to the design of marine reserves. For instance, placement of a marine reserve in a sink habitat would lead to a false sense of security and would not prevent local extinction of a heavily exploited population. This investigation tests a key hypothesis derived from the earlier findings: poor habitat quality in some sites reduces recruit survival disproportionately and thereby decouples larval supply and subsequent adult abundance. It includes both mensurative and manipulative experiments, specifically to measure the absolute availability of settlement and nursery habitat, to quantify abundance and survival rates of post?settlement and young juvenile spiny lobster, and to quantify population parameters at the four sites. The study therefore constitutes a unique empirical test of the collective influence of physical transport, habitat quality and adult abundance upon the recruitment dynamics of marine species.