CAREER: Connectivity Among Marine Fish Populations: Emphasizing Ecological Links Between Estuaries and the Coastal Ocean through an Integrated Program of Interdisciplinary Res/Educ

职业：海洋鱼类种群之间的连通性：通过跨学科研究/教育综合计划强调河口和沿海海洋之间的生态联系

• 批准号: 0134998
• 负责人: Simon Thorrold
• 金额: $ 88.32万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0134998&HistoricalAwards=false
• 关键词: CAREER; Connectivity; Among; Marine; Fish

The need for spatially?explicit models of marine populations has become obvious as fisheries scientists search for alternatives to traditional management strategies for marine resources. Efforts to develop spatial models for marine fish populations have been handicapped, however, by the absence of quantitative estimates of exchange rates among geographically?separated groups ("connectivity"). This lack of knowledge is primarily due to the difficulty of conducting mark?recapture studies in species that are characterized by the production of large numbers of small pelagic offspring that suffer high initial mortality rates. In this study, Dr. Thorrold will continue development and application of a marking approach that relies upon natural variations in the geochemistry of fish otoliths (ear bones) as a marker of source location. Recent work suggests that it is possible to track individual fish from juvenile nursery areas to adult spawning locations using these geochemical signatures as a natural tag of natal location. The otolith is an ideal natural tag because:Deposition time of any material in the otolith can be determined by reference to periodic increments in the otolith.Otoliths are metabolically inert, and material is not re?worked or re?sorbed after deposition.The chemical composition of the otolith reflects, to some degree, the environment in which the fish has lived. They will begin with a series of laboratory studies to investigate factors influencing the elementalcomposition of otoliths in larval Atlantic silversides (Menidia menidia). Then characterizegeochernical signatures in otoliths of young?of?the?year (YOY) Menidia from 10 estuaries along the coastof New England. Otoliths will be assayed for VC, 8"0, "Sr/16 Sr ratios, and a number of trace elements(Mg/Ca, Mn/Ca, Sr/Ca and Ba/Ca). This process will include the development of a technique forquantifying 87 Sr/ 86 Sr isotope ratios in otoliths using multi?collector inductively coupled plasma massspectrometry. The resulting multivariate chemical signatures in these otoliths will be used to developmaximum likelihood estimators to classify adult Menidia returning to estuarine waters to spawn thefollowing year. Otoliths ftom spawning adults will be sectioned to reveal the section of the otolith laiddown during juvenile residency in their natal estuary. A combination of micro?drilling and laser ablationICP?MS will be used to assay geochemical signatures in this portion of the otolith. Adult fish collectedfrom each of the 10 estuaries will be assigned to natal estuary based on the MLE algorithm developedfrom ground?truthed signatures of juveniles captured in the estuaries the previous year. These data willprovide quantitative estimates of connectivity through natal homing and straying in a coastal fish specieson an unprecedented spatial scale. More generally, the study will provide a framework for research aimedat quantifying connectivity in marine ecosystems through the use of natural signatures in calcifiedstructures of marine organisms. The educational component of the proposed research will include thedevelopment of topics courses in fisheries ecology and oceanography for the MIT[WHOl joint program inbiological oceanography, the mentoring of undergraduates on summer student fellowships at WHOI, andthe development and implementation of teacher training workshops for high school teachers inMassachusetts. They will focus on a common fish species that is a critical component of coastal habitatswith which students are most familiar. The ability to track the movements of fish from the backdoors oflocal students to other estuarine and coastal habitats will stress the interconnectedness of salt marshes,estuaries and the coastal ocean.

随着渔业科学家寻找传统海洋资源管理策略的替代方案，对海洋种群的空间显式模型的需求已经变得明显。然而，由于缺乏对地理上分离的群体之间汇率的定量估计(“连通性”)，为海洋鱼类种群建立空间模型的努力受到了阻碍。这种缺乏知识的主要原因是很难对以产生大量小型远洋后代为特征的物种进行标记-再捕获研究，这些后代的初始死亡率很高。在这项研究中，索罗尔德博士将继续开发和应用一种标记方法，该方法依赖于鱼类耳石(耳骨)的地球化学性质的自然变化，作为来源位置的标记。最近的研究表明，使用这些地球化学特征作为出生地点的自然标记，可以追踪从幼鱼苗圃到成鱼产卵地点的个体鱼。耳石是一种理想的自然标记，因为：耳石中任何物质的沉积时间都可以参照耳石中的周期性增量来确定。耳石是一种代谢惰性物质，沉积后物质不会重新加工或重新吸收。耳石的化学成分在一定程度上反映了鱼类生活的环境。他们将首先进行一系列实验室研究，以调查影响大西洋银鱼幼体耳石元素组成的因素。然后描述了新英格兰沿岸10个河口的幼年梅尼迪亚(YoY)耳石中的生物化学特征。将对耳石进行Vc、8“0、锶/16锶比值和一些微量元素(镁/钙、锰/钙、锶/钙和钡/钙)的分析。这一过程将包括开发一种使用多收集器电感耦合等离子体质谱技术来定量测定耳石中87Sr/86Sr同位素比值的技术。在这些耳石中产生的多变量化学特征将被用来开发最大似然估计器，以对返回河口水域下一年产卵的成虫进行分类。产卵成体的耳石将被剖切，以揭示幼体在其出生的河口居住期间的耳石部分。显微钻探和激光消融-电感耦合等离子体质谱将被用来分析耳石这一部分的地球化学特征。从10个河口采集的成鱼将根据根据前一年在河口捕获的幼鱼的地面真实签名开发的最大似然算法被分配到新生河口。这些数据将通过在前所未有的空间尺度上对沿海鱼类物种的出生、归宿和流浪提供定量的连通性估计。更广泛地说，这项研究将提供一个研究框架，旨在通过利用海洋生物钙化结构中的自然特征来量化海洋生态系统中的连通性。拟议研究的教育部分将包括为麻省理工学院开发渔业生态学和海洋学的专题课程，生物海洋学的联合计划，指导世界卫生组织的本科生暑期奖学金，以及为马萨诸塞州的高中教师开发和实施教师培训讲习班。他们将专注于一种常见的鱼类物种，这是学生们最熟悉的沿海栖息地的关键组成部分。能够跟踪鱼类从当地学生的后门转移到其他河口和沿海生境的能力，将强调盐沼、河口和沿海海洋的相互联系。