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.

由于渔业的当前死亡率水平与被剥削物种的长期进化史上的任何事物不同，因此，渔业是一种强大的生态力量。 将渔业效应理解为扰动的原因提供了有关调节骨膜生态系统结构和功能的生态过程的重要课程。 上一个项目，层生态系统中的Apex捕食者，重点介绍了北太平洋中部（CNP）生态系统中的营养相互作用，基于三个尺度的建模分析：单个鱼类物种的生物能学，捕食者 - 捕食者相互作用的相互作用和生态系统模型。 在模型开发的所有三个领域中，长期渔业对金枪鱼，比尔鱼和鲨鱼的生态影响一直是一个一致的主题。 主要的教训是：1。表征营养的本体发育是建立有效模型的关键组成部分，该系统强烈重叠使用了猎物资源和敌人内部的捕食，2。渔业已成为CNP营养结构变化的主要原因。 该项目将支持第一个项目的延续和扩展。 Kitchell博士和合作者将开发可以评估渔业效应在食品网络动态中的作用的模型，并扩展该模型，包括与大规模环境效应的相互作用，例如由于ENSO，PDO和/或气候变化动态而引起的，并使用随后的模型来评估可以改变生态系统结构和功能的基础。 将实现三个主要目标：建模实验方法。 他们为中北太平洋（CNP）开发了一种营养相互作用和渔业效应模型，部分原因是将人口规模的数据与食品网络信息和渔业发展史相结合。 在南太平洋中部（CSP）中存在一个生态类似物，渔业的发展是后来发生的。 研究人员将使用CNP方法来开发CSP模型，然后进行相当于由于渔业发展而对营养变化的独立复制分析。 合并这些模型会创建一个单个工具，可以评估在大规模上下文中表达的局部效应。 将渔业描述为新捕食者的等效物，可以评估食物网中的.strong相互作用以及从渔业效应中产生的复杂反馈机制。 建模以包括环境驱动力。 他们将由于ENSO，PDO和/或我们的CNP，CSP模型以及通过国家生态分析和合成中心（NCEAS）赞助的协作（NCEAS）赞助的ESTERS Tropical Pacific（ETP）的类似模型而表达的ENSO，PDO和/或全球变化效应引起的环境强迫。 研究人员将使用评估人口数据中异常情况的统计方法作为区分渔业与环境迫使渔业的影响的基础，从而改变了主要的生产率及其在较高营养水平的生产中的表达。 旁观和生态互动。 主要的保护问题围绕着这些上层生态系统中受到威胁或濒危乌龟，鸟类，鲨鱼和比尔鱼的旁捕捉。 DR，Kitchell和同事将使用“场景”方法来模拟替代管理行动，渔业开发过程变化的可能反应，其随之而来的生态变化及其社会经济后果。 现在，基本的EcoSIM模型包括使用鱼价投入以及基于就业，保护和/或生态系统管理的目标加权评估后者的能力。