Summary of Questionnaire Responses

Appendix A lists the questions provided to the workshop participants. Written responses to the questionnaire are summarized here. Although most of the questions were directed towards modeling, many of the responses were much broader in scope, and included comments on empirical observations and what is needed both from an observational-empirical and modelling perspective to improve our understanding of secondary production in the ocean.

Not surprisingly, responses on the ultimate goal were diverse, ranging from specifics on modeling goals and approaches to a very broad view of understanding how marine ecosystems are structured and how they function. Time-dependent, three-dimensional models that couple physics and biology were consistently emphasized. Useful models should consider in situ growth and reproduction, spatial gradients in target species abundances, abundances of potential prey and predators and their interactions with the target species, and realistic animal behavior. They should include the detail necessary to provide 1) an understanding of the processes and mechanisms which affect the vital rates (birth, growth, reproduction) of zooplankton, 2) accurate hindcasts of the distribution and abundance of the targeted species, with special emphasis on hindcasting interannual variability, and 3) a framework for evaluating the impact of potential climate change on the structure and dynamics of zooplankton populations in different marine ecosystems.

Other emergent themes resulted from the responses to the questionnaire. First, there is a need for a unifying conceptual framework in marine secondary production ecology. There are many models of zooplankton population dynamics and secondary production-including complex models, simple models, single species models, multiple species models, individual-based models (IBMs), metapopulation models, models that include no, some or extensive physics, and time-dependent and equilibrium models. One feature universal to most, if not all, of the models, however, is that they are untested and therefore of little general value. Validation and testing of models, which involves the cooperation of empiricists and modelers, is critical to improving our understanding of zooplankton production.

Responses indicated an interest in understanding the linkages (coupling) between major components; for example, how variability in fish stocks and recruitment is related to physical forcing; how short-term, but perhaps extreme, environmental or physical events influence secondary production and population structure.

More detailed responses to the questionnaire are presented in Appendix B.

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