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