Collaborative Proposal: Population Spatial Structure and Stage-specific Connectivity of the Toothfishes Dissostichus eleginoides and D. mawsoni

合作提案：齿鱼 Dissostichus eleginoides 和 D. mawsoni 的种群空间结构和特定阶段的连通性

• 批准号: 0338294
• 负责人: Julian Ashford
• 金额: --
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-15 至 2008-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0338294&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Population; Spatial; Structure

Patagonian toothfish (Dissostichus eleginoides) and Antarctic toothfish (D. mawsoni) are widely sold in the North American market as Chilean sea bass. On the basis of genetic evidence, toothfish are managed as discrete stocks within sub-areas frequently corresponding to island groups under the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR), and by neighboring national authorities. Management as discrete stocks assumes that each represents a closed population driven by its own births and deaths, and any vagrants are effectively lost. There is increasing evidence that toothfish can move considerable distances; however, rates of movement have proved difficult to examine. The elemental structure of growth increments in fish otoliths reflects the composition of water passing across the gills, and therefore the environment in which a fish is located; the growth increments also provide a chronological record of the life history up to capture. Otolith trace element signatures serve as a record of a fish's location in the past, and laser-based Inductively-Coupled Plasma Mass Spectrometry has been used by the principal investigators to examine elemental signatures in the otoliths of Patagonian toothfish (Dissostichus eleginoides), and to identify significant differences between management areas.Using this technique to sample the location on the otolith corresponding to the known date and site of capture, elemental signatures will be characterized over time and across the major areas of toothfish concentration in the Southern Ocean. Using toothfish taken recently, the elemental signatures recorded in the otolith during the life history will be compared with the corresponding spatial signatures determined in the ground-truthing analysis. Divergence between the two signatures will indicate that fish originated from outside the area of capture. The elemental data will then be used to estimate the proportion of fish currently in the population that have immigrated, and the life stage during which they migrated. By collecting otoliths and genetic samples from each fish, otolith microchemistry will be used to identify source populations and make effective use of multilocus data to not only characterize the distribution of genetically distinct stocks, but also to provide baseline data for estimating admixture proportions. By developing a set of chemical and genetic markers for both species, a comprehensive characterization of source populations and an accurate estimation of admixture proportions will be provided. As part of this research, international collaborations will include scientists working in the high Antarctic. This work will draw on these collaborations to further the integration of physical-biological components to clarify boundaries to the movement of toothfish. The project will provide scientific data will be of value in the Antarctic Treaty system on managing resources in the Southern Ocean. This proposal will also involve development of interdisciplinary studies that include minority and underrepresented, undergraduate, and graduate students.

小鳞洋枪鱼（Dissostichus eleginoides）和南极洋枪鱼（D. mawsoni）作为智利海鲈鱼在北美市场广泛销售。根据遗传学证据，洋枪鱼是作为离散种群在《南极海洋生物资源保护公约》（南极海生委）经常对应于岛屿群的分区内管理的，并由邻近国家当局管理。作为离散种群的管理假设每个种群都代表一个由其自身出生和死亡驱动的封闭种群，任何流浪者实际上都是迷失的。有越来越多的证据表明，洋枪鱼可以移动相当长的距离;然而，运动的速度已被证明很难检查。鱼耳石中生长增量的元素结构反映了穿过鳃的水的组成，因此也反映了鱼所处的环境;生长增量也提供了捕获前生活史的时间记录。耳石微量元素特征记录了鱼过去的位置，主要研究人员使用基于激光的电感耦合等离子体质谱法来检查巴塔哥尼亚齿鱼耳石中的元素特征（Dissostichus eleginoides），利用这种技术，在耳石上对应于已知日期和地点的位置进行采样，随着时间的推移，将在南大洋洋枪鱼集中的主要地区描述元素特征。使用最近采取的洋枪鱼，在生活史中的耳石记录的元素签名将与地面实况分析中确定的相应的空间签名进行比较。两个特征之间的差异将表明鱼类来自捕捞区域以外。然后，将使用基本数据估计目前已移民的鱼类在种群中所占的比例，以及它们迁移的生命阶段。通过收集每种鱼的耳石和遗传样本，耳石微化学将用于识别源种群，并有效利用多位点数据，不仅描述遗传上不同的种群的分布，而且为估计混合比例提供基线数据。通过为这两个物种开发一套化学和遗传标记，将提供源种群的全面表征和混合比例的准确估计。作为这项研究的一部分，国际合作将包括在南极高地工作的科学家。这项工作将利用这些合作，进一步整合物理生物成分，以澄清洋枪鱼运动的边界。该项目将提供科学数据，对《南极条约》系统管理南大洋资源具有价值。该提案还将涉及跨学科研究的发展，包括少数民族和代表性不足，本科生和研究生。