The U.S. GLOBEC program selected the Georges Bank area of the Northwest Atlantic as the first region for intensive study. The reasons were:
In Phase II, research will again focus on target species that are key elements in the planktonic assemblages of the Georges Bank region: pelagic larval stages of codfish (Gadus morhua), haddock (Melanogrammus aeglefinus) and the copepods Calanus finmarchicus, Pseudocalanus moultoni, and Pseudocalanus newmani. Hypotheses concerning these species for Phase II involve retention and loss of water and animals from over and around Georges Bank. Tests of those hypotheses involve four main activities:
Broad-scale field survey: This includes monthly shipboard surveys covering the bank with plankton and hydrographic stations in a clockwise grid, multi-disciplinary moorings and analysis of satellite data. Shipboard sampling will continue to determine the distribution and abundance of the target organisms in relation to their physical environment and to flow during the larval phase of cod and haddock (January through June). Long-term moorings will continue to monitor variations in flow and the response of flow to the wind. Satellite pictures will continue to provide the synoptic view of regional events needed for full interpretation of other data types necessarily less comprehensive. The broad-scale survey will provide the basis for inter-annual comparisons from which we expect to construct a scenario for the impact of climate change.
Process Studies: Process studies are nested within the broad-scale observations to investigate specific biological and physical processes. The focus in 1995 was on the influence of water column stratification on vital rates of the target species. The approach used was to identify and follow a patch of organisms while investigating the physical-biological interactions. The focus in 1997 will be on processes associated with source, retention, and loss of water and organisms as they impact the population dynamics of target-species on the Bank (See Report #6, pgs 36-39 for more detail). Close cooperation and interaction between the broad-scale and process components of the program is essential.
Modeling: Modeling studies are essential to the formulation and testing of hypotheses, to the interpretation of the data from the field studies, and to the integration of the results. Modeling studies to date have focussed on the development of 3-D models of the flow field of the Georges Bank and the surrounding regions, and linkages to the population dynamics of target species. In addition to site-specific modeling, modeling with a more regional scope is planned. Further, these efforts will incorporate more realistic biological/physical interaction and to allow for data assimilation.
Retrospective Analyses: Retrospective studies of existing data sets provide a means of investigating the biological and physical consequences of climatic variation. Previous studies have included processing of archived samples and interpretation of existing data sets. These studies will continue to look at past data sets and sample collections that allow integration, coordination, and comparison of Georges Bank data sets with those from other North Atlantic regions.