Initial Science Plan - Exec Summary

## Executive Summary

### Rationale

Compelling evidence exists showing that the physical environment of the earth is in flux. Considerable recent debate has raged over the question of how closely observed climate change can be related to enhanced production of greenhouse gases and other anthropogenic influences. Regardless of the relative contributions of human activities to global climate change, it is clear from paleoceanographic studies that global climate has varied tremendously even within recent geologic periods. Transitions between ice ages and warmer periods are numerous. The question is not whether climate change will happen but how rapidly. Along with global climate change, toxic chemicals and wastes are being introduced into the air and water in quantities sufficient to cause fundamental changes in the life support systems of the earth. Nutrient levels are becoming substantially enhanced in the waters of the globe. Several large research initiatives are now underway to assess the significance of these changes to our global climate, physics, and geochemistry. GLOBEC (GLOBal ocean ECosystems dynamics) is designed to evaluate the likely consequences of these changes in global climate and physics to the sustainability of animal production in the sea.

The approach of GLOBEC is to understand how physical processes, both directly and indirectly, influence the success of individual animals in the sea, their feeding, growth, reproduction, and survivorship. From this information can be derived the consequences of changing physical processes on animal populations and ecosystems. Models of global climate can then be used to relate global change to changes in regional ocean physics and, subsequently, changes in regional physics to shifts at the scales of events that influence the individual organism. Effects on zooplanktonic life stages will be emphasized because so many marine animals undergo at least one planktonic life stage and because the planktonic size classes are most at the mercy of the physics of their fluid environment.

GLOBEC is the vehicle to plan, promote, and coordinate this physical-biological partnership needed to assess the consequences of changing global climate on marine animal production. We envision substantial progress arising from the development and application of new technologies for sampling, from the interactive collaboration of physical oceanographers and marine biologists, and from the stimulation and opportunity that this initiative provides to investigators in the ocean sciences community.

### Guidance From the Scientific Community

The directions taken by GLOBEC have their origins in the recommendations made at several workshops organized to discuss the most compelling scientific issues facing each of the component scientific disciplines represented within GLOBEC (see Appendix A for details). In specific, meetings of ocean scientists interested in fish populations (Fish Ecology I, II, III), zooplankton (the Lake Arrowhead Colloquium), benthic invertebrates (the Nearshore Benthic Ecology Meeting), long time-series observations (Deep-Sea Observatories Workshop), and coastal physical oceanography (the CoPO planning process) have contributed guidance and stimulation to the GLOBEC planning groups. The present set of plans for GLOBEC is derived from the guidelines, recommendations, and mandates of three workshops explicitly organized to evaluate the scientific need for global ocean ecosystems studies and to provide guidance for the evolving research initiative: the National Academy of Sciences meeting on recruitment and ocean ecosystems dynamics, the Wintergreen GLOBEC workshop, and the Halifax planning meeting for a GLOBEC study in the Northwest Atlantic Ocean.

Participants in these workshops and planning meetings reached widespread consensus on several recommendations, all of which have been incorporated fundamentally into the GLOBEC science plan:

1. Base the approach on fundamental mechanisms at the level of the individual organism that influence growth, reproduction, and mortality, thereby effecting population change and ecosystem responses;

2. Effect a cooperative partnership between physical and biological oceanographers, dedicated to solving the problems of how changing global climate might affect ocean physics and thereby directly and indirectly alter ocean ecosystem dynamics;

3. Develop a research program based upon interactive feedbacks between coupled physical-biological models and field observations/experiments; and

4. Promote development and utilization of new technologies and instrumentation to redress the problem of chronic undersampling of the sea, a problem especially critical for zooplanktonic animals.

### Progress and Plans for Major Program Elements

#### Modeling

From analyses performed by the GLOBEC working group on modeling in 1989, the steering committee decided that several initial modeling efforts would be necessary to initiate promptly prior to mounting any specific field program to help guide the field studies and to resolve certain key questions about what measurements need to be taken, at what resolution, and under what conditions. An announcement of opportunity was prepared and released by NSF (the National Science Foundation) in February 1990 to solicit proposals for these initial modeling studies:

- Conceptual studies of simplification and predictability to address how scaling, pooling, and averaging might be appropriately applied to simplify measurement needs in ocean ecosystems dynamics models and how environmental variability of a variety of sorts might influence the degree of predictability possible in ocean ecosystems dynamics;

- Prototype investigations of biological processes in idealized flows to address how flow regimes affect biological processes at the level of the individual, population, community, and ecosystem and how sensitive results are to enhancing the realism and complexity of the flow regime; and

- Preliminary site-specific models addressing the mechanistic interactions of the physics and biology and relating the ocean physics to global change through necessary intervening scales and processes.

#### Field Studies Combining Modeling/Observation

The intention of the GLOBEC steering committee is to develop an understanding of the fundamental mechanisms by which ocean physics contribute to ecosystem dynamics, especially in the planktonic environment. We hope to be able to develop formal models combining biological and physical variables that have sufficient generality to be broadly applicable, with appropriate site-specific modifications,, to planktonic systems in the sea. This approach implies intensive study of physics and ecosystem dynamics in a small number of carefully chosen study systems, with subsequent extension to additional systems that include physical and biological processes not adequately represented in the initial study systems.

Through this process of testing, validating, and elaborating on a core set of physical/biological models, GLOBEC intends to examine the implications of global change on animal abundance and production in the major ocean basins. In each ocean basin, ocean ecosystems dynamics will be associated with those key physical changes most likely to be triggered by global change. Planning has begun and progressed to differing degrees for the following field sites:

- Northwest Atlantic - Our planning process is most advanced for this system as a consequence of the Halifax workshop in June 1990 to plan U.S.-Canadian cooperative efforts as a part of the international Cod and Climate Change (CCC) program covering the North Atlantic ocean. In 1991, we anticipate release of an NSF Announcement of Opportunity to further preparations for a pilot study of how changes in global circulation of water masses driven by global climate change are likely to influence regional physics in the vicinity of Georges Banks and how those changes in turn are expected to alter the ecosystem dynamics that dictate the abundance and production of codfish, sea scallops, and those holoplanktonic zooplankters integral to the ocean food webs. We anticipate further planning to integrate this NSF-supported activity with NOAA (National Oceanic and Atmospheric Administration) studies of fisheries dynamics and oceanography in this region.

- Eastern Pacific - Plans for GLOBEC sites in the Eastern Pacific will become more focused in 1991 through workshops to assemble interested scientists to identify the best approaches and sites to evaluate them. The steering committee has decided to proceed with planning workshops to assess the value of a GLOBEC study in the California Current ecosystem as representative of an Eastern Boundary Current system. In addition, we are interested in developing plans, possibly in conjunction with CoOP (Coastal Ocean Processes), to examine the consequences of global change in the higher latitude Alaska Current and Bering Sea Shelf ecosystems, where temperature change and precipitation change could dramatically affect these buoyancy-driven flows.

- Southern Ocean - We expect to initiate planning activities for the Antarctic region through initial workshops sponsored by federal agencies such as NOAA and NSF. Global change is expected to have its most intense effects in the higher latitudes, including changes in air temperature, ice cover, freshwater inputs, and UV radiation. These form reasonable candidate changes to investigate in a GLOBEC study of Southern Ocean ecosystem responses.

- Indian Ocean - We anticipate study of the implications of global change for the dynamics of monsoon processes in this ocean basin, with subsequent study of how the physical-biological couplings imply ecosystem responses. The Office of Naval Research (ONR) is reviewing a program to study the physical-biological couplings of the monsoon system in the Indian Ocean that we hope to involve in the GLOBEC quest to understand the likely consequences of global change on ocean physics and ecosystems dynamics.

- Other Study Systems - Although our primary interest is to uncover fundamental and general processes whereby ocean physics affect ecosystems dynamics by in-depth investigation of some small number of prototype systems, particularities and idiosyncrasies of other systems will doubtless require additional site-specific studies of further physical phenomena and their biological consequences. In specific, we expect to develop plans for study of how climate change may affect ocean circulation around tropical islands and coral reefs and the ecosystem implications of those changes. We also anticipate a need to examine how the bounded nature of the Great Lakes and peculiarities of the life histories of their freshwater biota may require changes in the ecosystem dynamics models and conclusions developed from studying ocean ecosystems.

#### Technology

The GLOBEC working group on technology prepared a review in 1989 of the most promising technological solutions to the problems of undersampling and of time-lagged sampling of zooplanktonic animals in the sea. Our ability to couple physical and biological processes into models of important dynamical events and interactions is at present grossly compromised by the limitations of biological sampling. Effective evaluation of most important coupled physical-biological processes will require quantum jumps in the speed and resolution of zooplankton sampling so as to approach the capability of synoptic sampling. Three sets of instrument systems were considered as possible solutions to this technology problem. The working group explored the merits, limitations, feasibility, and likely costs of a rapid (probably acoustics-based) zooplankton mapper, a shipboard counter by size (probably using optics) and taxon (possibly utilizing molecular genetic tags or optical information), and a field profiler (probably incorporating the Multi-frequency Acoustic Profiling System, MAPS).

A special technology session at the Halifax workshop was directed towards establishing priorities for action to promote development of desired new technologies for GLOBEC research. The recommendations included organization of a biotechnology workshop to evaluate alternative possible technologies for assessing the physiological state of planktonic animals and for identifying planktonic animals by taxon. The recommended biotechnology workshop has now been held and a GLOBEC workshop report will soon be available describing the proceedings. In addition, the technologists meeting in Halifax recommended assembly of a group of acousticians and experts on optics to make further recommendations on how to promote use of these technologies in oceanographic instrumentation necessary for GLOBEC investigations. This meeting will be conducted later in 1991. The GLOBEC steering committee also anticipates need to customize physical instrumentation, such as the Acoustic Doppler Current Profiler (ADCP), to provide the coverage and performance necessary for study of critical physical dynamics, especially those both high and low in the water column.