U.S. GLOBEC Georges Bank Phase IV-B PI Meeting
December 5, 2005; 1300 to 1630
WHOI Redfield 2-04

Attendees: Peter Wiebe, Cabell Davis, Changsheng Chen, Dick Limburner, Jim Bisagni, Bob Beardsley, Charlie Flagg, Rubao Ji, John Steele, Greg Lough, Jon Hare, Larry Buckley, Jeff Runge, Ted Durbin, Avigit Gangopadhyay, Dian Gifford, David Mountain, Robert Groman

The agenda for the meeting was:

There are four continuing projects from Phase VI A. Five new projects have been identified for funding in Phase IV B, with a sixth that may yet be funded. For a list of all projects and access to the project summaries click here.

Reports by the continuing projects:

1. Physical oceanography of Georges Bank and its impact on biology (Beardsley et al.)
The long-term mooring data is almost finalized and a data report nearly completed. In 1999 the data indicates a 4-day current oscillation that is coherent spatially and appears to be a new phenomenon not previously observed. A number of manuscripts have been or are nearly completed (Brink, Ledwell & Churchill, Lerczak and Bisagni). The modeling activity by Chen has made considerable progress, with a high resolution tidal model running and a data assimilation capability demonstrated for a one year simulation. This needs to be further validated. Remote forcing is still an issue (e.g. what is coming in from upstream). Analysis of the long-term variability in water properties by Flagg is now focusing more on the Slope Water region, with an apparent Labrador Slope Water event in 1996 that occurred without a preceding drop in the NAO.

2. Zooplankton population dynamics on Georges Bank: model and data synthesis (Franks et al.)
Jeff Runge presented the project update. Manuscripts have been submitted on modeling the retention of dormant copepods in the Gulf of Maine (Johnson, Pringle, Chen) and on the vital rates of Calanus finmarchicus (Johnson and Gentlemen). The latter found major differences between the GLOBEC years and the MARMAP decade. During GLOBEC the Calanus abundance was 3 to 6 times higher and the timing of the seasonal abundance increase was earlier than in the earlier period.

3. Patterns of energy flow and utilization on Georges Bank (Gifford et al.)
This project combines a top down consumption model for the upper trophic levels with a bottom up production model of the lower levels for the Georges Bank food web. Four time stanzas are considered, each characterized by different physical conditions and fish population structure. One striking result of the modeling is that the plankton requirements of pelagic fish community in the first stanza (1960's) was much lower than the abundance of plankton indicated by the GLOBEC data. The conclusion is that the plankton abundance was lower in the earlier years, perhaps due to large-scale environmental conditions at the time. Related data sets from the period offer support for this conclusion.

4. Tidal front mixing and exchange on Georges Bank: controls on the production of phytoplankton, zooplankton, and larval fishes (Houghton et al.)
The report was given by Chen and Lough. Considerable effort has been given to getting the small-scale temperature variability right in the model. Once the model gets that right, it can get the dye dispersion right. Resolving bottom topography has been found to be critical in getting the tidal nutrient pumping right. A manuscript on the larval prey field is nearing completion. Also, the larval dynamics model now appears properly parameterized and results have been published from an earlier project. This modeling component is now ready to be combined with the physical component for the tidal front region.

Reports on the newly funded projects in Phase IV B:

5. Processes controlling abundance of dominant copepod species on Georges Bank: local dynamics and large-scale forcing (Davis et al.)
Independent of this project, but as background for it, the VPR data from 1997 and 1999 has been getting processed and will be available. In analyzing the cross-frontal transport in 1999, the model could get dye movement correct, but the Calanus population didn't show up where the dye went. Predation on Calanus is believed to be the cause. In modeling the retention/loss of Calanus from the 1997 study on the southwest corner of the bank, little retention and mainly loss or transport toward the Middle Atlantic Bight was found. The current project will consider both local and large-scale physical forcing on the development of Calanus. Model domain extends to Halifax, NJ, and offshore into the Slope Water region. A primary question is to what degree is the Calanus population in the Gulf of Maine/Georges Bank self-sustaining vs being dependent on input from Labrador Sea? The spatial patterns of the Calanus populations are believed to result from the interaction of life-history traits and physical transport. The modeling will use FVCOM with and NPZ component to get phytoplankton fields. These results will then feed into a copepod life stage model for dominant species that also will be concentration-based.

6. Impact of climate and basin-scale variability on seeding and production of Calanus finmarchicus in the Gulf of Maine/Georges Bank region (Gangopadhyay et al.)
This project will look at the large basin-scale and long time scale variability of the physical environment. It will compare high vs low NAO periods (1980-1993, 1962-1971), using an IBM approach to model the Calanus populations for the NW Atlantic. It will then look on a finer scale at the GLOBEC region during the 1988-1999 period using NAO simulations from a NASA project.

7. Effects of climate variability on Calanus dormancy patterns and population dynamics in the Northwest Atlantic (Runge and Leising)
This project will investigate the factors controlling diapause by Calanus. This is an extension of a similar project previously funded in the GLOBEC California Current program. The intent is to identify environmental conditions controlling dormancy, with temperature and food supply believed to be the primary drivers. The core hypothesis is that regional differences in populations could be due to differences in dormancy patterns caused by different temperature and food conditions. There are a number of data sets from different regions to support the analysis.

8. Factors determining early-life-stage survival and recruitment variability in N. Atlantic cod: a comparison between NW Atlantic and Norwegian Sea systems (Werner et al.)
This will be a comparative study between cod on Georges Bank and in the Norwegian Sea, and will involve a close collaboration with Norwegian researchers who have been doing GLOBEC-like studies of cod. The effort will use a basin-scale circulation model, with increased resolution in two regions of interest, and include IBM tropho-dynamic models for larvae and early juveniles. For Georges Bank the focus will be on 1995, 1998, 1999, while for the Norwegian Shelf 1985, 1986 and, perhaps, some other more recent overlapping year, will be analyzed. Werner will be at IMR (Bergen) for a few months in 2006 to work on the basin-scale modeling.

9. Marine ecosystem responses to climate-associated remote forcing from the Labrador Sea (Greene et al.)
This project will investigate the importance of remote forcing from the Labrador Sea on the Gulf of Maine/Georges Bank region. Of particular interest is the advection of low salinity water that was a major aspect of the physical variability on Georges Bank during the GLOBEC years. In addition, the impact of this variability in the Middle Atlantic Bight also will be investigated. A working group of researchers who have been working on these and other related topics will define the approaches and data sets to be used in addressing issues. They also will provide guidance to two graduate students who will carry out the identified analyses. In addition, another project with a comparable working group is considering how climate variability can be incorporated into fisheries models used in management. Interaction between the two working groups is planned to promote passing of information and results between the two projects.

10. Effect of marine reserves on cod and haddock population dynamics: application of GLOBEC results to ecosystem management (Hare et al.)
This project has not been identified for funding, but may yet be in the near future. It will address developing applications for use in ecosystem-based management. The spatially explicit models from GLOBEC will be combined with a spatially explicit population model for the reproducing adult cod stock. The effects of varying climate conditions and of the presence/absence of closed areas (with no harvesting of the adult cod) will be investigated.

Future meetings and collaboration among the projects: How the Georges Bank program as a whole will move forward was discussed. It was generally agreed that regular, though perhaps somewhat informal, meetings where the various projects present their progress and exchange ideas would be very helpful. To accomplish this, a capability to hold the meetings remotely via the web or some form of video conferencing could save money and allow more investigators to take part. This will be an issue for all of the regional GLOBEC programs and should be brought up at next week's GLOBEC SSC meeting.

The New EXCO: It was decided that each new project will identify two persons to form the new Executive Committee, since the continuing projects will soon end. Each project leader should send the names to Bob Groman by the end of this week. The first meeting will be scheduled after the new committee is constituted.

Last modified: December 8, 2005