Collaborative Research: GLOBEC-01: Patterns of Energy Flow and Utilization on Georges Bank

该项目基于美国-GLOBEC在西北大西洋的研究，综合了生产和能量流动的关键方面，并利用来自其他来源的关于食物网较低和较高水平的生产过程的信息来增强美国-GLOBEC的数据。主要目标是考察GLOBEC和GLOBEC相关研究的几个替代模型结果，这些研究有助于解决一些悬而未决的问题，并重新检查乔治斯滩的能量流动模式。这项研究加强和扩展了以前的调查结果，明确考虑了该系统早期模型中没有涉及的因素，包括：(1)微生物食物网，(2)考虑新的和循环的初级生产，(3)乔治斯浅滩初级和次级生产的空间异质性，(4)较高营养水平的生物量和产量的变化，以及(5)环境强迫对生产过程的影响。将这些要素纳入建模工作中，可以更详细地了解世行的生产流程。前四个元素提供了更广泛的生态系统背景，而最后一个元素提供了与美国-GLOBEC计划的主要主题之一--气候变化的链接。正在通过比较反映不同环境和鱼类群落制度的几个不同年代尺度的时间段来解决后一种问题：(1)1960年代寒冷，特征是远洋船队捕捞丰富的底层鱼类种群；(2)1970年代，特征是水温“平均”，国内捕捞努力增加，底层鱼种群枯竭；(3)1980年代，特征是水温“平均”，底层鱼类种群过度捕捞，板鳍类鱼类增多；(4)1990年代“平均”温度，盐度较低，特征是捕捞死亡率降低，底层鱼类种群恢复，以及棘鱼和中上层鱼类数量增加。由于过度捕捞导致鱼类群落结构的大规模变化，如果不考虑其他生态系统组成部分的变化，就无法充分了解目标物种的种群动态。目前正在制定代表上述每一个时期的个别模型网络。随后，将开发动态模型来描述这些制度之间的转变或转变。

This project synthesizes key aspects of production and energy flow, based on US-GLOBEC studies in the Northwest Atlantic, and augment the US-GLOBEC data with information from other sources on production processes at the lower and upper levels of the food web. The primary objectives examine several alternate model outcomes of GLOBEC and GLOBEC-related studies that help address a number of outstanding issues and re-examine patterns of energy flow on Georges Bank. This research enhances and expands the findings of previous investigations, with explicit consideration of factors not addressed in earlier models of this system including: (1) the microbial food web, (2) consideration of new and recycled primary production, (3) spatial heterogeneity of primary and secondary production on Georges Bank, (4) changes in biomass and production at higher trophic levels, and (5) the effects of environmental forcing on production processes. Incorporation of these elements into the modeling effort permits a more detailed understanding of production processes on the Bank. The first four elements provides the broader ecosystem context, while the last provides the link to one of the US-GLOBEC program.s principal themes, climate change. The latter is being addressed by comparing several different decadal-scale time periods that reflect differing environmental and fish community regimes: (1) the cold 1960s characterized by abundant groundfish stocks fished by distant water fleets; (2) the 1970s, characterized by "average" water temperatures, increased domestic fishing effort, and depletion of groundfish stocks; (3) the 1980s, characterized by "average" water temperatures, overfishing of groundfish stocks, and increases in elasmobranchs; and (4) the "average" temperature, lower salinity 1990s, characterized by reduced fishing mortality, rebuilding of groundfish stocks, and increases in elasmobranchs and pelagic fish. Because of large-scale changes in the fish community structure as a result of over-exploitation, a full understanding of the population dynamics of the target species will not be attained without consideration of changes in other ecosystem components. Individual model networks are being formulated to represent each of the above periods. Subsequently, dynamic modeling will be developed to describe the transformations or shifts between these regimes.