Collaborative Research: GLOBEC 2000: Feeding, Growth, Condition, and Energetics of Juvenile Pink Salmon in the Gulf of Alaska

该项目的目标是确定阿拉斯加湾北部的粉红鲑鱼在出海的头几个月里如何受到浮游生物生产系统变化的影响。这将通过一个综合项目实现，该项目包括实地采样、实验室分析和建模。粉红鲑鱼夏季占据大陆架表层水域，春季进入海水后进入秋季。在此期间，它们生长迅速，摄食从夏季的小型浮游动物转变为秋季的大型浮游动物。该项目将记录猎物使用和可获得性的时间和空间变化，将通过测量粉红色鲑鱼的状况来评估货架环境的影响，并将使用空间显式觅食/生物能量模型来了解观察到的摄食、生长和条件模式。来自孵化场的鱼，通过热耳石标记识别出来，将是特别有意义的，因为每个孵化场队列的海洋存活将在这些鱼进入海洋环境一年后获得。粉红鲑鱼饲料和表层浮游动物的时空变化将通过对现场样本的实验室分析来描述，而食物转向较大猎物的基础将通过计算猎物的选择性来确定。将计算标准长度/重量条件测量，并用热量计测量三文鱼的能量含量。将考察条件、生长和环境之间的关系。大陆架上的栖息地质量将通过具有觅食和生物能量成分的空间显式模型进行评估，这些模型产生特定重量的增长潜力估计。生物能量模型也将被用来估计粉红色三文鱼的每日配给和季节性消费。这项研究将直接有助于实现GLOBEC计划的目标，即了解上层营养层物种的生产如何与海洋条件的变化有关。人们普遍认为，果阿的鲑鱼产量是由浮游生物产量决定的。对食物、猎物可获得性、温度和鱼类状况的时空变化的详细描述将大大增强我们对海洋环境和鲑鱼生产之间的联系的理解。

The goal of this project is to determine how pink salmon in the northern Gulf of Alaska are affected by variation in the plankton production system during their first months at sea. This will be accomplished through an integrated project that includes field sampling, laboratory analyses and modeling. Pink salmon occupy surface waters of the continental shelf in the summer and fall after entering marine waters in the spring. In that period they grow rapidly and their feeding changes from small zooplankton in the summer to large zooplankton in the fall. This project will document temporal and spatial variation in prey use and availability, it will assess the effects of the shelf environment by measuring condition of pink salmon, and it will use spatially- explicit foraging/bioenergetic modeling to understand observed patterns in feeding, growth and condition. Fish of hatchery origin, identified by thermal otolith marks, will be of particular interest, as the marine survival of each hatchery cohort will be available a year after those fish enter the marine environment.Spatial and temporal variation in pink salmon diets and surface zooplankton will be described through laboratory analyses of field samples, and the basis for diet shifts to larger prey will be determined by calculations of prey selectivity. Standard length/weight condition measures will be calculated, and the energy content of salmon will be measured by calorimetry. The relationship between condition, growth and the environment will be examined. Habitat quality over the continental shelf will be assessed with spatially explicit models with foraging and bioenergetic components that produce weight- specific estimates of growth potential. Bioenergetic modeling will also be used to estimate daily ration and seasonal consumption by pink salmon. The relationship between diets of pink salmon and other planktivorous fishes will be assessed.This research will contribute directly to accomplishment of the GLOBEC program goal of understanding how production of upper trophic level species is linked to variation in oceanographic conditions. It is widely accepted that production of salmon in the GOA is determined by planktonic production. Detailed descriptions of spatial and temporal variation in diet, prey availability, temperature, and fish condition will substantially enhance our understanding of the connections between the marine environment and salmon production.