OO - Workshop Summary

## Workshop Summary and Recommendations

The Workshop recommended a stepwise implementation, from modest, single-investigator efforts to large scale field programs starting about 5 years from now. It was agreed that "open ocean" would mean the temperate, subtropical and tropical central regions of the world oceans, including the borders of gyres and with emphasis on the epipelagic zone. It was agreed to concentrate on zooplankton or fishes >100 µm in size.

Central to the plan is selection of a small number of target species having stable circumglobal distributions in several oceanic gyres and tractable for process and population studies. Selecting species for open ocean studies that have (1) life histories that are known, (2) low genetic diversity, and (3) minimal physiological (non-genetic) variation, will maximize the opportunity for detecting environmental impacts of climate change in the different ocean regions. Target species would become the focus of population dynamics research conducted as time-series and transects in several parts of the world ocean. These efforts would be allied with other large programs that provide data on global climate conditions.

The proposed implementation plan includes:

Retrospective analyses.

- A literature review to summarize patterns of biomass distribution, species diversity, and community structure in the Atlantic, Pacific and Indian ocean gyres. This would identify a preliminary pool of target species.

- An analysis of existing data or samples from the central Atlantic, Indian and/or South Pacific to look for patterns of species distribution, diversity and dominance to compare with the North Pacific gyre.

Pilot scale studies. These are small efforts conducted at single sites (i.e., JGOFS time-series sites), from platforms of opportunity, or on dedicated cruises. Their goals include selecting final target species.

- A comparison of new and conventional sampling techniques to establish the best ways to sample all life stages of target species.

- Sampling in different ocean basins to establish distribution patterns of potential target species. A north-south transect in the North Atlantic could provide data complementary to those from the North Pacific gyre.

- Sample collection for genetic analyses to establish the boundaries of populations within or between ocean basins.

- One or more cruises should repeat earlier (1960-1980) transects in the North Pacific gyre to compare species abundance and diversity patterns over the past three decades.

- Develop and/or evaluate emerging techniques for measuring process rates (e.g., growth, reproduction, mortality, energetics) on the target species.

- Establish, with international cooperation, land-based sites in parts of the temperate and tropical ocean where simple measurements of climate and hydrography could be made and samples of zooplankton or fishes taken over long time periods.

Dedicated Open Ocean Programs. These would be larger-scale studies aimed at the target species over 1-2 year time periods. The nature and scope of these efforts would be dictated by results of the pilot studies and available funding. Emphasis would be placed on establishing population characteristics and dynamics rather than bioenergetic processes, although the latter might play a supporting role. Micro- and meso-scale physical characteristics of the environment would need to be investigated simultaneously with the biological studies. In order to assess responses to global scale climate change, key population parameters and vital rates for the target species would have to be studied again after 5-20 years.