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

本研究是基于对加勒比龙虾招募的前期研究，在超种群和来源的理论框架下进行的。在巴哈马埃克苏马湾的四个广泛间隔的地点（超过100公里）进行的汇动力学研究。这些发现是基于实地抽样、实地实验和一个2？D物理迁移的水动力模型，产生了描述物理迁移、栖息地质量和成体丰度对刺龙虾招募的共同影响的概念模型。结果表明：4个样地3年内的成虫数量和成虫数量的空间格局基本一致，成虫数量和成虫数量在空间上呈解耦关系，在很大程度上解释了成虫数量的空间格局(？67%的中尺度变化)由幼虫和幼虫后通过环流和地转流运输。这表明，栖息地质量和物理运输在空间上使物种补充和成虫丰度脱钩，从而产生了物种来源？水槽网络。这些研究结果对了解海岸保护区的招募过程和安置情况，以加强招募工作具有重要意义。特别是，这些结果的新颖之处在于它们论证了基本水动力过程对幼虫供应的直接和强有力的控制，并将其应用于海洋保护区的设计。例如，将海洋保护区安置在水槽栖息地将导致一种虚假的安全感，并不能防止当地被严重剥削的人口灭绝。这项调查验证了从早期发现中得出的一个关键假设：一些地点的栖息地质量差，不成比例地减少了成虫的存活率，从而使幼虫供应和随后的成虫数量脱钩。它包括测量和操作实验，特别是测量定居和苗圃栖息地的绝对可用性，量化后的丰度和存活率？并对四个地点的小龙虾种群参数进行量化。因此，这项研究是对实际运输、生境质量和成虫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.