Physical and Biological Processes Linking the Sources of Larval Production to Subsequent Recruitment into Subtidal Benthic Communities

这个项目将调查幼虫的生产、分布、定居和招募之间的相互作用，并确定这些因素如何影响潮下底栖群落的结构和物种组成的差异。之前使用一种新开发的自动采样设备的研究表明，许多无脊椎动物物种的补充发生在淡水期，特别是在退潮期间。这种模式可能解释了一些底栖生物物种如何即使在动荡的环境中也能维持当地持久的种群。为了评估这一发现的普遍性，奥斯曼博士及其合作者将进行一系列实地调查，主要目标有四个。首先，他们将研究潮汐水动力和与海湾相关的运输，以建立水运动、幼虫分布和补充之间的模式和相互关系。其次，科学家将调查幼虫产生、释放、可获得性和招募之间的空间和时间关系。实验将集中在三组不同的物种上；一组具有强大的本地来源和短寿命(小时)的幼虫(殖民地海鞘、苔藓虫)，第二组具有同样强大的本地来源但具有较长寿命(天)的幼虫(一些单独的海鞘)，以及第三组具有分布的长寿幼虫(例如藤壶)。第三，调查人员将研究招募如何影响更大区域人口中亚群体的建立和长期维持。实验将量化新兵进入一个地区的移民情况，确定他们的存活率，评估他们复制和成为当地人口的能力，并检查随后的人口维持情况。实地研究将把新开发的测量底栖物种幼虫和新兵的设备与测量大范围水流和局部湍流强度的标准技术结合起来。最后，将开发一个数值模型来预测不同生活史物种的幼虫和新兵的空间分布。该模型将潮汐流动知识与从实验中获得的幼虫生产、分布、定居和补充的定量描述结合起来。该模型对这些因素的合理变化的敏感性将被用来评估我们预测海洋种群和群落动态的时空变异性的能力。

Whitlach9819489This project will investigate the interplay between larval production, distribution, settlement, and recruitment and to determine how these factors influence differences in the structure and species composition of subtidal benthic communities. Previous studies using a newly developed automated sampling device indicate that recruitment of many invertebrate species occurs during slack water periods, particularly at low tide. This pattern may explain how some benthic species can maintain locally persistent populations even in turbulent environments. To assess the generality of this finding, Dr. Osman and collaborators will conduct a series of field investigations with four primary objectives. First, they will examine tidal hydrodynamics and associated transport withip an embayment in order to establish the patterns and correlations among water movement, larval distributions, and recruitment. Second, the scientists will investigate the spatial and temporal relationships between larval production, release, availability, and recruitment. Experiments will focus on three distinct groups of species; one with strong local source areas and shortlived (hours) larvae (colonial ascidians, bryozoans), a second group with equally strong local sources but with longer-lived (days) larvae (some solitary ascidians), and the third with a distributed regional source of long-lived larvae (e.g. barnacles). Third, investigators will examine how recruitment influences the establishment and long-term maintenance of sub-populations within a larger regional population. Experiments will quantify the immigration of recruits into an area, determine their survival rates, evaluate their ability to replicate and become a local population, and examine subsequent population maintenance through multiple generations. The field studies will combine newly-developed devices for measuring larvae and recruits of benthic species with standard techniques for measuring large-scale currents and local turbulence intensities. Finally, a numerical model will be developed to predict spatial distributions of larvae and recruits for species with different life histories. The model will combine knowledge of tidal flows with quantitative descriptions of larval production, distribution, settlement, and recruitment obtained from experiments. The model's sensitivity to plausible variations in these factors will be used to assess our ability to predict spatial and temporal variability in marine population and community dynamics.