Apex Predators in the Pelagic Zone

远洋区域的顶级掠食者

• 批准号: 9731531
• 负责人: James Kitchell
• 金额: $ 54.23万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9731531&HistoricalAwards=false
• 关键词: Apex; Predators; Pelagic; Zone

Exploitation of apex predators in pelagic food webs should result in a set of ecological changes at several scales. We will determine the dynamics of compensatory responses by apex predators (large tunas, billfishes and sharks) and some of their primary prey (squids, small tunas and juvenile mahimahi) in the pelagic food webs of the Central North Pacific (CNP). We will test for fishery-induced changes in growth rates, predator-prey interactions (diets), life history characteristics such as size or age at maturity, and species composition of the fish community. Analyses of food web dynamics will be used to evaluate the ecological consequences of changes in exploitation. We will use retrospective analyses of long-term data sets provided by collaboration with the Honolulu Laboratory, National Marine Fisheries Service. Responses to `pulse` manipulations will derive from analyses of recent evidence for major, rapid changes in exploitation effects, prey availability, and environmental effects (oceanic regime shifts). Responses to `press` manipulations of apex predator populations will derive from the 35-50 year records of basic biological data, life history studies and catch data maintained by NMFS. Contemporary data on growth rates, diets, life history characteristics, and species composition will be compared with those collected since 1948. This effort will employ three classes of analytical tools. Time-series methods and Bayesian models will be used to discern signal from noise and to identify the interactions of causative variables. Bioenergetics models will provide quantitative estimates of the changes in food web linkages for individual predators, their prey and the cumulative change for all members of the apex trophic guild. A new simulation model (Ecosim II) creates the food web context of an entire ecosystem and will be used to explore responses to changing mortality rates, different life history strategies and the role of a habitat refuge created around the Northwest Hawaiian Islands. The recent rise of conservationist concern for large predatory fishes is based on their unknown role in sustaining the ecological integrity of pelagic ecosystems. It is imperative that we better understand the effects of these migratory predators and their interactions with habitats encompassed by current and future refuges for pelagic fishes. That understanding must be set in the context of environmental changes that dampen or amplify food web effects.

在上层食物网中对顶点捕食者的开发应导致多个尺度的一系列生态变化。 我们将确定顶点捕食者（大型金枪鱼，比尔鱼和鲨鱼）及其一些主要猎物（鱿鱼，小金枪鱼和少年摩ia）在北太平洋中部太平洋（CNP）中的一些主要猎物（鱿鱼，小金枪鱼和少年摩ahi）的动力学。 我们将测试渔业诱发的增长率变化，捕食者 - 捕食者相互作用（饮食），生活史特征，例如成熟时的大小或年龄以及鱼类群落的物种组成。 食品网络动态的分析将用于评估剥削变化的生态后果。 我们将使用与国家海洋渔业服务檀香山实验室合作提供的长期数据集的回顾性分析。 对'脉冲操作的响应将从最近对剥削效应，猎物可用性和环境效应（海洋状态转移）的重大变化的证据分析得出。 对顶点捕食者种群的“媒体操纵”的反应将从NMFS维护的基本生物学数据，生命史研究和捕获数据的35 - 50年记录中得出。关于增长率，饮食，生活历史特征和物种组成的当代数据将与自1948年以来收集的数据进行比较。这项工作将采用三类的分析工具。 时间序列方法和贝叶斯模型将用于辨别噪声的信号并确定因果变量的相互作用。 生物能模型将对各个捕食者的食物网络联系的变化，其猎物和所有Apex营养公会成员的累积变化提供定量估计。 一个新的仿真模型（EcoSIM II）创建了整个生态系统的食物网络环境，并将用于探索对不断变化的死亡率，不同生活历史策略以及围绕西北夏威夷群岛创造的栖息地避难所的作用的反应。 保护主义者对大型掠食性鱼类的关注的兴起是基于它们在维持上层生态系统的生态完整性方面的未知作用。 我们必须更好地理解这些迁徙捕食者的影响及其与当前和未来避难所所包含的栖息地的相互作用。 这种理解必须基于衰减或扩大食物网络效果的环境变化的背景。