Linking juvenile habitat utilization to population dynamics of California halibut
Linking juvenile habitat utilization to population dynamics of California halibut
复制标题
将幼鱼栖息地利用与加州大比目鱼种群动态联系起来
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Lisa A Levin
中科院分区：
文献类型：
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作者：
F. Fodrie;Lisa A Levin
我们研究了四个沿海生态系统对加州大比目鱼(Paralichthys CalforNicus)的育苗作用：(1)对年龄级鱼类的贡献；(2)由于鱼类从幼体迁移到亚成体栖息地而导致的海岸系统的连通性；(3)幼体栖息地的使用和可用性对亚成体种群数量的影响，特别是评估了集中度假说。潜在的托儿所使用一种稳健的分类方案进行分组，该方案将暴露环境、海湾环境、泻湖环境和河口环境分开。通过元素指纹对个别亚成体鱼类的育苗来源进行分配表明，2003年裸露的海岸、海湾、泻湖和河口对幼鱼生长的贡献分别为31%、65%、1%和3%，而2004年分别为49%、33%、16%和2%。这些结果与实地调查得出的“预期”托儿所贡献非常相似，表明在这个系统中，幼体分布是衡量幼体栖息地单位面积生产力的良好指标，幼体阶段的密度依赖机制并不调节补充脉冲。元素指纹分析还表明，从海湾迁出的个体并没有远离它们的苗圃起源(10公里)，导致在大约一代人的时间尺度上，110公里研究区域的连通性降低。因此，我们观察到大海湾附近的亚成虫密度相当高，而远离大海湾的种群似乎更受苗圃栖息地限制的影响。在大尺度(~100公里)范围内，苗圃栖息地选择的位置和可用性对南加州鱼纲动物群落的一个重要成员的种群动态有显著影响。
We investigated the nursery role of four coastal ecosystems for the California halibut (Paralichthys californicus) using the following metrics: (1) contribution in producing the fish that advance to older age classes, (2) connectivity of coastal systems resulting from migration of fish from juvenile to subadult habitats, and (3) effect of nursery habitat usage and availability on subadult population size, specifically evaluating the concentration hypothesis. Potential nurseries were grouped using a robust classification scheme that segregated exposed, bay, lagoon, and estuarine environments. Assignment of nursery origins for individual subadult fish via elemental fingerprinting indicated that exposed coasts, bays, lagoons, and estuaries contributed 31%, 65%, 1%, and 3% of advancing juvenile halibut during 2003, versus 49%, 33%, 16%, and 2% during 2004, respectively. These results were remarkably similar to “expected” nursery contributions derived from field surveys, suggesting that in this system juvenile distributions were a good indicator of unit‐area productivity of juvenile habitats and that densitydependent mechanisms during the juvenile phase did not regulate recruitment pulses. Elemental fingerprinting also demonstrated that individuals egressing from bays did not migrate far from their nursery origins (<10 km), resulting in reduced connectivity along the 110‐km study region over the timescale of approximately one generation. Consequently, we observed considerably higher subadult densities at sites near large bays, while populations distant from large bays appeared to be more influenced by nursery habitat limitation. Over large (~100 km) scales, the location and availability of nursery habitat alternatives had significant effects on the population dynamics of an important member of the ichthyofaunal community of southern California.