## Executive Summary

From 23-25 February 1993, twenty-one scientists from the physical and biological community with expertise in modeling and empirical observations, met in Savannah, GA for a U.S. GLOBEC sponsored workshop on secondary production modeling. The goal of the workshop was to assess the present state of secondary production modeling in the sea and to provide recommendations for future research directions. Of particular importance, the workshop identified several scientific areas that are, perhaps, presently limiting advancement in the modeling of zooplankton population dynamics and production.

Following nine overview presentations, the participants formed working groups to discuss issues related to three of these scientific areas: 1) animal behavior; 2) integration across scales and the linking of information at different scales; and, 3) structural aspects of secondary production models. The primary recommendations that resulted from these working group discussions are to:

- Develop models that include our understanding of the mechanics underlying animal behaviors, including proximal and ultimate environmental factors controlling behavior.

- Develop nested models that encompass biological processes from the level of the individual to the level of the population. Such models must bridge a wide range of temporal and spatial scales, i.e., from the local to the regional in space, and from the hourly to the annual in time.

- Develop detailed mechanistic models for a few key zooplankton species that allow for the inclusion of inter-individual variability, including genetics. These models need to consider more complex structural aspects of the system that impact the key species, such as the dynamics of primary producers and microzooplankton grazers, which represent much of the prey resources for the larger zooplankton.

Besides these specific recommendations of the working groups, two recurrent themes emerged from the plenary and working group discussions. First, there was a consensus for the development of stronger ties between empiricists and modelers at all scales. Scale considerations include temporal, spatial, and ecological (individuals to populations to ecosystems). Moreover, cooperation between empiricists and modelers will become more important as biological models move toward the development of fully data assimilative models. Two way interactions are needed: empiricists need to consider the, potentially unique, data requirements of the modelers-e.g., the types of data, and their spatial and temporal frequency; modelers, on the other hand, need to consider the observationalist's ability to collect suitable data, and the empiricist's need for parameter estimation. Second, it is desirable to make biological models, especially models of zooplankton population dynamics, accessible to a broader segment of the biological oceanographic community. This is especially true for those models that couple the biological dynamics of populations to the physics of the environment, particularly when more than one dimension is included. U.S. GLOBEC should support the development of a biological oceanography community model(s), similar to those available for physical oceanography.