Collaborative Research: Radiometric Age Validation of the Patagonian and Antarctic Toothfishes (Dissostichus Eleginoides and D. Mawsoni)

合作研究：巴塔哥尼亚和南极齿鱼（Dissostichus Eleginoides 和 D. Mawsoni）的辐射年龄验证

• 批准号: 0231919
• 负责人: Julian Ashford
• 金额: $ 4.07万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0231919&HistoricalAwards=false
• 关键词: Collaborative; Research; Radiometric; Age; Validation

Recent years have seen the re-establishment of large-scale marine resource utilization by humans in the Antarctic. In contrast to early sealing and whaling activity, the modern impact is directed on krill and finfish populations, most notably of the Patagonian toothfish (Dissostichus eleginoides), but also its congenor the Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea. Toothfish are a valuable resource and are likely to continue to command a high price in world markets. However, extensive illegal fishing has lead to considerable concern that Patagonian toothfish populations are being over-harvested. In other parts of the world, over-harvesting of larger, commercially valuable species has led to fishing down of marine food webs, leaving impoverished, less valuable ecosystems. The goal of the Convention for the Conservation of Antarctic Marine Living Resources, part of the Antarctic Treaty System, is to allow harvest while avoiding disruptions to the Antarctic ecosystem. To achieve this, the sustainable management of the fishery depends on reliable age data. Age data allow population age structure to be modeled, so that growth, mortality and recruitment rates can be estimated and used to understand population dynamics. Age data provides the basis to determine the life history pattern of a species, to model population dynamics, and to determine which age classes are vulnerable to over-exploitation under a particular set of environmental conditions. Current age and growth information for toothfish is based on age determination methodologies which are not validated and depend on the specific laboratory and principal investigator. Recently, the Commission of the Conservation of Antarctic Marine Living Resources has endorsed three preparation methodologies using otoliths and a common set of criteria for estimating age from otolith micro-structure. The CCAMLR Otolith Network has also been initiated as a medium for exchanging samples to ensure that age estimates are comparable between readers and laboratories. However, considerable work is needed to ensure that age estimates generated by the three methodologies are accurate. One technique that has been successful is radiometric age determination, which uses the disequilibria of lead-210 and radium-226 in otoliths as a natural chronometer. This proposal brings together an international collaboration to examine population age structure for both toothfish species, in an experimental design built around radiometric validation tests of age data generated by all three preparation methodologies. To integrate the validation component within an Antarctic-wide effort to examine toothfish population age structure, sub-samples for validation work will be drawn from sample sets taken for population age studies by research teams working in Australia, New Zealand, the United Kingdom and France, as well as the United States. Scientists at Moss Landing Marine Laboratories will use radiometric age determination to independently age otoliths from Patagonian and Antarctic toothfishes. Scientists at Old Dominion University will use a system already established for aging to generate validated age data, allowing growth, mortality, and longevity to be estimated by geographic areas. The project will provide validated otolith sample sets that can be used as a foundation for a unified and validated age estimation system for the toothfishes. This study will provide information which will be disseminated to the public, policy-makers and the international community. The project will provide opportunities for under-represented students at both universities.

近年来，人类在南极重新建立了大规模的海洋资源利用。与早期的海豹和捕鲸活动相比，现代的影响主要针对磷虾和鳍鱼种群，最明显的是巴塔哥尼亚齿鱼（Dissostichus eleginoides），但也包括它在罗斯海的近亲南极齿鱼（Dissostichus mawsoni）。齿鱼是一种宝贵的资源，可能会继续在世界市场上占据高价。然而，大规模的非法捕捞已经引起了人们对巴塔哥尼亚齿鱼种群被过度捕捞的担忧。在世界其他地区，过度捕捞具有商业价值的大型物种导致了海洋食物网的捕捞，使生态系统变得贫瘠，价值降低。作为南极条约系统的一部分，《南极海洋生物资源养护公约》的目标是允许捕捞，同时避免破坏南极生态系统。为实现这一目标，渔业的可持续管理取决于可靠的年龄数据。年龄数据允许对人口年龄结构进行建模，从而可以估计人口增长率、死亡率和新入率，并用于了解人口动态。年龄数据为确定一个物种的生活史模式、模拟种群动态和确定在特定的一组环境条件下哪个年龄组容易受到过度开发提供了基础。目前犬牙鱼的年龄和生长信息是基于年龄测定方法的，这些方法未经验证，取决于特定的实验室和主要研究者。最近，南极海洋生物资源养护委员会核准了使用耳石的三种制备方法和一套从耳石微观结构估计年龄的共同标准。CCAMLR耳石网络也作为交换样本的媒介，以确保读者和实验室之间的年龄估计具有可比性。然而，需要做大量的工作来确保由这三种方法产生的年龄估计是准确的。一种成功的技术是放射性年龄测定法，它利用耳石中铅-210和镭-226的不平衡作为天然计时器。该提案汇集了一个国际合作来研究这两种犬牙鱼的种群年龄结构，在一个实验设计中，围绕由所有三种准备方法产生的年龄数据的辐射验证测试。为了将验证部分纳入南极范围内检查齿鱼种群年龄结构的努力，将从澳大利亚、新西兰、联合王国和法国以及美国的研究小组为种群年龄研究所采集的样本集中抽取用于验证工作的子样本。莫斯兰丁海洋实验室的科学家们将使用放射性年龄测定法来独立测定巴塔哥尼亚和南极犬牙鱼的耳石年龄。老道明大学（Old Dominion University）的科学家们将使用一个已经建立的老龄化系统来生成有效的年龄数据，从而可以根据地理区域来估计生长、死亡率和寿命。该项目将提供经过验证的耳石样品集，可作为统一和有效的牙鱼年龄估计系统的基础。这项研究将提供资料，分发给公众、决策者和国际社会。该项目将为两所大学中代表性不足的学生提供机会。