Georges Bank, located off Cape Cod has long supported important commercial fisheries. From 1996 to 2008, NCCOS partnered with the National Science Foundation supporting the Global Ocean Ecosystems Dynamics Program (GLOBEC), part of the U.S. Global Change Research Program. The GLOBEC Northwest Atlantic Program goal was to understand the population dynamics of key species (cod, haddock, and two zooplankton) and predict changes in their populations as a result of climate variability and change.
Why We Care
Traditionally one of the most productive fishing regions in the United States, by the late 1980s and early 1990s the Georges Bank region gained national attention due to the collapse of the traditional groundfish stocks and the economic burden the collapse put upon the local fishing communities. The collapse of the northwest Atlantic groundfish fisheries focused the attention of both management and science on critical gaps in knowledge. Spawning stock biomass of cod had become so sufficiently low that some fishery areas were closed in 1993, and in 1995 the closure area was expanded.
Effective management of the Georges Bank fisheries harvest requires understanding how long-term ecosystem variability influences the reproductive success of the stocks. The U.S. GLOBEC Northwest Atlantic studies on Georges Bank brought understanding to how changes in environmental conditions related to stratification, retentive circulation features, and exchange across frontal zones affect the dynamics of the target copepods (Calanus finmarchicus and Pseudocalanus spp.) and fish (cod and haddock) species. Changes in growth and survival of the target fish species due to changes in food supply (including the target copepods) and the physical environment have important implications for recruitment to the fisheries for these valuable species.
What We Did
The GLOBEC Georges Bank program had three years of extensive field process study (1995, 1997, and 1999). Phase 1 (1994–1996) focused on stratification of the water column and its effects on circulation around Georges Bank. Phase 2 (1996–1999) examined the sources, retention, and loss processes affecting zooplankton populations on Georges Bank. Phase 3 (1999–2000) determined cross-frontal exchange processes and how they influenced populations moving onto and off of the bank.
Over one hundred cruises took place during the field work of the program, with scientists spending 1,174 days at sea on missions that described physical and biological conditions on the bank during January through June of every year from 1995–2000. Moorings were in place continuously during this time, recording information over a long time series. Process studies focused both on the links between the target species and their physical environment and the determination of fundamental aspects of key species’ life history (birth rates, growth rates, death rates, etc.). In 2002, the Georges Bank program entered a final phase of synthesis and modeling activities in which the results of the various process, retrospective, and broad-scale studies were integrated.
The final phase of GLOBEC Georges Bank focused on analysis and synthesis of the field results with special attention to physical/biological modeling, climate effects, and development of indices to characterize environmental and ecosystem status and change. The modeling efforts were a very important part of the program that led to an integrated view of the dynamics of the populations. Retrospective analysis provided information over a longer time frame and helped place the current study in historical context. Over 50 research projects were jointly or separately funded by NCCOS and NSF. NCCOS support helped participants that would not normally be eligible for NSF support, such as researchers from federal agencies.
Benefits of Our Work
Key indices were developed to monitor changes to the ecosystem. Models provided new, ecosystem-based estimates of abundances and distributions for improved fishery forecasts. Research results were provided routinely to the NOAA Fisheries Northeast Fisheries Science Center and to the New England Regional Fishery Management Council in their deliberations on the reopening of closed areas on Georges Bank to scalloping. GLOBEC NWA data and models have contributed greatly to the development of Integrated Ecosystem Assessments in the North Atlantic region.