Apex Predators in the Central Pacific: An Ecosystem Approach

中太平洋的顶级掠食者：生态系统方法

• 批准号: 0220941
• 负责人: James Kitchell
• 金额: $ 75万
• 依托单位: University of Wisconsin-Madison
• 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: 2003-01-01 至 2008-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0220941&HistoricalAwards=false
• 关键词: Apex; Predators; Central; Pacific; Ecosystem

The current levels of mortality owing to fisheries are unlike anything in the long evolutionary history of exploited species and, therefore, that fisheries are a powerful ecological force. Understanding fishery effects as causes of perturbation offers important lessons about the ecological processes that regulate structure and function of pelagic ecosystems. The previous project, Apex Predators in Pelagic Ecosystems, focused on trophic interactions in the central north Pacific (CNP) ecosystem based on modeling analyses at three scales: bioenergetics of individual fish species, predator-prey interactions and ecosystem models. The ecological effects of long-line fisheries for tunas, billfishes and sharks has been a consistent theme in all three areas of model development. The major lessons were that: 1. Characterizing trophic ontogeny was a key component to building effective models for this system of strongly overlapping use of prey resources and intra-guild predation, and 2. Fisheries have become and continue as the main cause of change in trophic structure of the CNP. This project will support continuation and expansion of the first project. Dr. Kitchell and collaborators will develop models that can evaluate the role of fishery effects in food web dynamics, expand that to include interactions with large-scale environmental effects such as those due to ENSO, PDO, and/or climate change dynamics and use the consequent models as a basis for evaluating resource management policies that can change ecosystem structure and function. Three major objectives will be pursued: Experimental Approach to Modeling. They have developed a model of trophic interactions and fishery effects for the central north Pacific (CNP) based, in part, on merging population-scale data with food web information and the history of fishery development. An ecological analogue exists in the central south Pacific (CSP) where fishery development occurred at a later time. The researchers will use the CNP approach to develop a CSP model, then conduct the equivalent of an independent, replicate analysis of the trophic changes owing to fishery development. Merging these models creates a single tool that allows evaluation of local effects expressed in a large-scale context. Characterizing fisheries as the equivalent of new predators allows an evaluation of .strong interactions in food webs and the complex feedback mechanisms that emerge from fishery effects. Modeling to Include Environmental Drivers. They will implement environmental forcing due to ENSO, PDO and/or global change effects expressed in our models of the CNP, CSP and a similar model of the eastern tropical Pacific (ETP) developed through collaboration sponsored by the National Center for Ecological Analysis and Synthesis (NCEAS). The investigators will use statistical approaches that evaluate anomalies in the population data as the basis for differentiating effects of the fisheries from those of the environmental forcing that alters primary production rates and its expression in production of higher trophic levels. Bycatch and Ecological Interactions. Major conservation issues revolve around bycatch of threatened or endangered turtles, birds, sharks and billfishes in these pelagic ecosystems. Dr, Kitchell and co-workers will use a "scenarios" approach to simulation of alternative management actions, the likely responses of changes in fishery exploitation processes, their consequent ecological changes and their socioeconomic consequences. The basic Ecosim model now includes the capacity to evaluate the latter using inputs of fish prices plus weighting for goals based on employment, conservation and/or ecosystem management.

目前渔业造成的死亡率与被开发物种漫长进化史上的任何水平都不同，因此，渔业是一股强大的生态力量。 将渔业影响理解为扰动的原因，为调节远洋生态系统结构和功能的生态过程提供了重要的教训。 上一个项目“远洋生态系统中的顶级捕食者”重点关注北太平洋中部（CNP）生态系统中的营养相互作用，基于三个尺度的建模分析：个体鱼类的生物能学、捕食者-猎物相互作用和生态系统模型。 延绳钓渔业对金枪鱼、旗鱼和鲨鱼的生态影响一直是模型开发的所有三个领域的一致主题。 主要经验教训是： 1. 描述营养个体发育特征是为这一猎物资源使用和行会内捕食高度重叠的系统建立有效模型的关键组成部分，以及 2. 渔业已经并继续成为导致物种变化的主要原因。 CNP 的营养结构。 该项目将支持第一个项目的继续和扩展。 Kitchell 博士和合作者将开发可以评估渔业效应在食物网动态中的作用的模型，将其扩展到包括与大规模环境影响（例如 ENSO、PDO 和/或气候变化动态造成的影响）的相互作用，并使用后续模型作为评估可以改变生态系统结构和功能的资源管理政策的基础。 将追求三个主要目标： 实验建模方法。 他们开发了北太平洋中部（CNP）的营养相互作用和渔业影响模型，部分基于将人口规模数据与食物网信息和渔业发展历史相结合。 南太平洋中部地区（CSP）也存在类似的生态情况，那里的渔业发展较晚。 研究人员将使用 CNP 方法开发 CSP 模型，然后对渔业发展造成的营养变化进行相当于独立、重复的分析。 合并这些模型创建了一个单一工具，可以评估大规模环境中表达的局部效应。 将渔业描述为新的捕食者，可以评估食物网中的强相互作用以及渔业效应产生的复杂反馈机制。 建模以包含环境驱动因素。 他们将实施由于 ENSO、PDO 和/或全球变化影响而产生的环境强迫，这些影响在我们的 CNP、CSP 模型以及由国家生态分析与综合中心赞助的合作开发的东热带太平洋 (ETP) 模型中表达。 （NCEAS）。 研究人员将使用统计方法来评估种群数据中的异常情况，作为区分渔业影响与环境强迫影响的基础，环境强迫改变了初级生产率及其在较高营养水平生产中的表现。 兼捕和生态相互作用。 主要的保护问题围绕着这些远洋生态系统中受威胁或濒临灭绝的海龟、鸟类、鲨鱼和长嘴鱼的兼捕。 Kitchell 博士和同事将使用“情景”方法来模拟替代管理行动、渔业开发过程变化的可能反应、随之而来的生态变化及其社会经济后果。 基本的 Ecosim 模型现在包括使用鱼类价格输入以及基于就业、保护和/或生态系统管理的目标权重来评估后者的能力。