1. Introduction A U.S. GLOBEC Georges Bank Phase 4B Scientific Investigators' meeting was held on October 2 - 3, 2006. This two-day meeting was held at the Woods Hole Oceanographic Institution's Quisset Campus, Clark Laboratory. (see: http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/agenda.html) The purpose of the meeting was to bring together investigators early in this final synthesis phase of the GLOBEC NWA program in order to coordinate efforts and review program goals. The specific goals of the meeting were to: 1) have researchers present an overview of their Phase 4B project together with any early results, 2) establish communication links and needs among projects, and 3) discuss the phase 4B projects within the context of the overall goals of the GLOBEC NWA program. The meeting began with Cabell Davis welcoming the group and presenting meeting logistics. Davis then reviewed the meeting goals and briefly reviewed the overall program goal of quantifying biological-physical mechanisms controlling recruitment of cod and haddock and their dominant copepod prey species. He presented a circle plot of haddock biomass-at-age data, which clearly shows the large cohorts. He pointed out that our ultimate objective is to provide insights into the causes of those "bonanza" year classes. Davis stressed that it is not just fish populations that are impacted strongly by recruitment processes, but most animal species with planktonic phases of life as well as holozooplankton, including the target copepod species. Davis then went over the interconnections between the different phase 4B projects, discussing how interdependent they are. The FVCOM-NPZD-copepod study (Davis et al) is focusing on understanding the internal biological and physical mechanisms controlling the lower-food web and copepod species dynamics in the GB/GOM region and the consequences of boundary forcing scenarios related to basin and global dynamics. It is necessary to understand the interior dynamics of the GB/GOM system in order to understand how the system responds to external forcing. The output of the FVCOM biophysical model will include concentration-based 3D abundances of dominant copepod species, which serve as prey for cod and haddock larvae. These copepod concentrations are critically needed in the larval fish modeling project (Werner et al.), which is combining individual-based models of cod and haddock with regional and basin physical models (ROMS) in order to compare the biological/physical processes controlling larval fish growth and survival in the GB/GOM region with that on the Norwegian shelf. The basin scale dynamics developed by Werner et al also can provide boundary forcing for the FVCOM model. The detailed analysis of mechanisms controlling diapause in Calanus (Runge et al) involves a combination of historical data analysis and IBMs and is critically important to the concentration based FVCOM copepod modeling (Davis et al) as well as to the basin-scale Calanus IBM study (Gangopadhyay et al). The basin-scale Calanus study also uses ROMS and therefore has strong links to the ROMS-based basin-scale larval fish study. The synthesis work being done relating global, basin, and regional dynamics (Greene/Pershing et al) helps tie together the 4B studies. Although this last study is focusing on freshwater input into shelf regions of the NWA from the Arctic, the planned workshops provide an excellent venue for discussions of remote forcing of the GB/GOM region in general and are therefore an integral part of phase 4B synthesis efforts. 2. Individual Project Talks Following this introduction and program overview, the individual project talks began. Four projects were presented in the morning session and two after lunch. Davis et al. Project: Davis presented an overview of the NPZD-copepod species FVCOM-modeling project, describing its main objectives, approach, hypotheses, and outputs. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Davis.html The main objective of this project is to model the biological-physical mechanisms controlling the development of 3D spatial patterns of lower food web (NPZD) and dominant copepod species on GB/GOM over time scales of days to years during the GLOBEC period (1995-1999). This modeling effort will examine how local-dynamics and external physical forcing impact the abundance of the target species. The study will determine the relative importance of food-limitation, predation, and advection. The FVCOM will be used together with GLOBEC and other data sets, to conduct targeted numerical experiments examining such factors as sustainability of resident populations (in the absence of immigration), the effects of intrusions of Labrador water from the slope and Scotian Shelf, and scenarios of catastrophic warming. The general hypothesis of the study is that the characteristic distributional patterns of the dominant copepod species are determined by the interaction of their characteristic life-histories and the biological and physical environment. A state-of-the-art unstructured-grid model, FVCOM, driven by tides and meteorological forcings, provides the 3D physical fields and incorporates biological components including lower trophic level food web (NPZD), stage-structured copepod species models, and a Lagrangian tracking tool for incorporation of individual-based models of selected species. Thus, inputs to the model include local dynamics and large scale forcing, and distributions of nutrients, phytoplankton, and copepod species. The model outputs 3D distributions of temperature, salinity, currents, nutrients, phytoplankton, microzooplankton, and copepod species at time steps of minutes over the 1995-1999 GLOBEC field study. The website for this project can be found here (http://www.whoi.edu/sites/G4Bcopepods). Following this overview, Changsheng Chen presented the overview of FVCOM physical model and the latest results, 1995-2005. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Chen.html (Insert chen summary here) Rubao Ji followed with a description of the NPZD-copepod species model and recent results. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Ji.html (Insert Ji summary here) Bob Beardsley then gave a brief overview of the Canadian modeling efforts in the NWA, a result of discussions with Peter Smith (BIO). http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Beardsley.html (Insert Beardsley summary here). Runge et al Project: Jeff Runge presented an overview and discussion of work on diapause mechanisms in Calanus finmarchicus. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Runge.html (Insert Runge summary here) Werner et al Project: Greg Lough presented an overview of the larval fish modeling project comparing the NWA with the Norwegian Sea. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Lough.html (Insert Lough summary here) Larry Buckley then presented his latest work on the growth and mortality in larval cod and haddock on Georges Bank. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Buckley.html (Insert Buckley summary here) Green et al. project: Pershing presented an overview of their synthesis project which examines the impact of remote forcing of the NWA by intrusions of low salinity water derived from the Arctic. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Pershing.html (Insert Pershing summary here) Gangopadhyay et al. project: Avijit Gangopadhyay presented the overview and status their project on basin scale modeling of Calanus finmarchicus distributions. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Gangopadhyay.htm l (Insert Gangopadhyay summary here) Jim Bisagni presented SST and mooring data revealing Scotian Shelf Water cross-overs during the GLOBEC years. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Bisagni.html (Insert Bisagni summary here) Anne-Marie Brunner presented a nice description of the interannual variability of satellite SST in the NWA from 1985-1999, showing the 1998 low salinity intrusion passing along the edge of the slope from the Scotian Self to the Mid-Atlantic Bight (MAB). http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Brunner.html (Insert Brunner summary here) Groman et al. Data Management: Bob Groman presented the status of the data management office activities. He described the inventory and the new interfaces developed to access and display these data using a geospatial interface. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/Groman.html (Insert Groman summary here) 3. Intra-interproject communications: Following the afternoon coffee break, "free" time was allotted for intra- and inter-project communications as needed. 4. Plenary discussion of themes The group reconvened in plenary session at 1600 to discuss major themes of the GLOBEC NWA program. The goal of this session, and of the working groups the following morning, was to place the individual 4B projects within the larger perspective of the project as a whole. Davis led off this plenary session with an overview of the major themes up for discussion: 1.What are the key mechanisms controlling recruitment success the target species? e. g., the bonanza year classes of haddock (1998, 2003) 2.What are the key ecosystem indicators 3.What are the physical and biological processes that link global/basin and the GB/GOM region? e.g. intrusions, warming, winds 4.What is the relative importance of top-down vs. bottom-up forcing of GOM/GB ecosystem? 5.What are the big ideas to come out of GLOBEC NWA? 6.What are the products/transitions of GLOBEC NWA? e.g. operational products, lead-ins to new scientific programs. This overview was followed by an introductory presentation, related to theme 3, by Dave Mountain on the low salinity event that characterized GLOBEC years 1996 and 1998. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/mountain/mountai n_GLIVB100206.ppt.htm (insert Mountain summary here) Andy Pershing then presented an introduction to theme 6 on transitioning the findings of GLOBEC NWA program to operational tools of use to managers. http://globec.whoi.edu/globec-dir/phase4doc/simeeting2006/talks/pershing/Pershin gGLOBECOpsIntro.ppt.htm (insert Pershing summary here). 5. Working group discussion of themes In the morning of day 2, a two-hour period was used for working groups to discuss the themes presented in plenary the previous afternoon. Participants were divided arbitrarily into two working groups. Each group was charged with discussing all the themes in order to obtain insights from all meeting participants on all the topics. 6. Working group reports on themes Report of working group 1. Present: Davis (Rapporteur), Beardsley, Runge, Lough, Buckley, Ji This working group had a general discussion with a large amount of overlap between themes. We first discussed the role of top down versus bottom up control of the ecosystem and target species. Two independent GLOBEC studies, Pershing et al (submitted) and Steele et al. (submitted), and a related study by Heath and Lough (in press) all have found strong support for the dominance of bottom-up control of the GB/GOM ecosystem. Pershing et al. compared the 1980s and 1990s, the so called MARMAP and GLOBEC decades, respectively, and found that the mean surface salinity of the GOM was lower during the 1990s than during the 1980s. This lower salinity was associated with higher fall phytoplankton, high abundance of small copepods during spring, higher herring stocks, and higher recruitment of haddock. Steele et al. used a combination of historical data and modeling to compare decadal scale changes in the Georges Bank ecosystem over the past 40 years. They concluded that, during the last three decades fish food requirements balanced lower trophic level production, whereas, during the 1960s, intrusions of low-nutrient Labrador Slope Water reduced primary and secondary production and overall fish yields. Heath and Lough (in press) found that CPR phytoplankton color index for the Gulf of Maine had both spring and fall peaks in the 1960s and 1970s but only a spring peak in the 1990s. This shift corresponds with the collapse of the cod spawning stock on Georges Bank in the 1990s. In the earlier period when stocks were high, significant spawning spanned the period from November to May, whereas in the 1990s spawning started about two months later, although peak activity still took place in February-March. Despite the apparent discrepancies in the fall phytoplankton bloom during the 1990s, the studies all suggest a strong bottom-up effect on fish production. The working group felt that both bottom up and top down processes operate on the system as a whole and different species may be affected in different ways. Bottom up effects do appear to strongly affect variability at the system level. In considering the effects of remote (climate/basin) forcing on the GB/GOM system, it was felt that, in keeping with the approach of the GLOBEC NWA, we need to understand the interior dynamics of the GB/GOM system in order to understand how the system will respond to external forcing. We felt that the proposed process oriented modeling is the right approach, i.e., conducting targeted numerical experiments to examine different forcing scenarios. Setting up boundary conditions for warm and cold regimes will be examined with respect to their influence on lower food web and copepod species production. By modeling the GLOBEC years, in which we have a rich data set, we will be able to examine the factors leading to "good" and "bad" years in terms of plankton production. The good years, like 1998 and 1999 provide necessary food conditions for outstanding year classes but are not a guarantee, e.g., haddock recruitment was high in 1998 but not in 1999. (Other factors like post-pelagic juvenile survival and cannibalism, not studied in GLOBEC, may contribute to recruitment success.) Such production estimates can be used as indices for ecosystem based fisheries management. The models we are developing provide abundance estimates for dominant copepod species (Calanus, Pseudocalanus, Oithona) which can be reduced to simple estimates, such as low, medium, high levels of large and small copepods. These indices can be compared in hindcast with good and bad year classes of cod and haddock. Other indicators include the biological state variables in the model, including nutrients and phytoplankton. The model variables can be combined into multivariate indices or principal components. Model variables to consider include wind, temperature, N-P-Z levels, copepod species abundances, larval fish growth and survival. From GLOBEC data, Buckley, Lough, and Mountain have found that ~50% of the variability in larval growth can be accounted for by seasonal effects and ontongeny (i.e. photoperiod and size), and another ~15% is due to a year effect. Thus we can account for a significant proportion of the total variance in larval growth and survival. The cause of the year effect is not yet known, but will be examined using the modeling studies. The remaining percentages are critically important to determine since a small change in mortality rate can have such a large impact on recruitment. A major finding of the GLOBEC program was that larval cod and haddock at times are food limited in nature, even in the food rich region of Georges Bank. Using the extensive GLOBEC data set, Buckley, Lough, and Durbin found a strong relationship between abundance of Pseudocalanus and larval fish growth, which is also related to survival (Mountain, in prep). This finding clearly indicates that bottom up effects are critical for these species. Thus using the model, we can identify the mechanisms leading to good and bad years of Pseudocalanus which will serve as a proxy index for larval fish growth and survival. Since survival, as well as growth, is affected by copepod abundance, this index may be very powerful. Historical data analysis indicates that remote forcing has a strong effect on bottom up processes though stratification, nutrient input, and wind driven flows. We will use the models to conduct numerical experiments to gain insight into these mechanisms. The modeling approach is needed to examine year to year effects of winds, warming, and stratification. One issue raised is that Pershing et al, found a relationship between low salinity and system production, and in another study found a relationship between NAO and Calanus from the CPR GOM transects. Although there is a relationship between NAO and Labrador Slope Water intrusions in the GOM, intrusions of low salinity water from the Scotian Shelf do not appear to be related to NAO (Mountain pers. comm.). Thus, if the enhanced system production in the GOM is in fact caused by low salinity intrusions from the Scotian Shelf, this enhanced production must not be related to NAO, but may be due to a longer term effect, probably polar ice melt. The relation of CPR-derived Calanus abundance to NAO then may be due to intrusions of Labrador Slope Water into the GOM and not to enhanced productivity from Scotian Shelf intrusions. Numerical experiments need to be done to compare the influence of salinity versus other aspects of remote forcing (global and basin), including wind forcing and surface heating. NAO effects do not appear to impact local meteorological conditions in the GB/GOM region (Beardsley cited Joyce study), but the influence of longer term global trends in warming and wind forcing on the GB/GOM ecosystem need to be examined. In terms of transitioning the GLOBEC findings and models for use by managers, it was felt that it is not the role of GLOBEC scientists to run operational models, but it certainly is our responsibility to provide models that can be transitioned to operational groups such as NOS. The models we are developing will be tested in hindcast mode and can be run in nowcast and in the end, in forecast mode. The models will provide estimates of lower food-web and copepod species production as well as recruitment of fish through the larval stage. In this way, the models will provide indices of system productivity and good and bad years for larval fish survival as a function of local and remote forcing. The models are not expected to provide high-frequency (e.g., daily) forecasts, but are likely to provide indicators of value for 1-10 years into the future. The models are being calibrated on the GLOBEC years (1995-1999) and extended to present time. The use of our model-generated ecosystem indices can be used together with current spawning stock biomass estimates to help fisheries managers make better predictions. These models also will serve as useful tools for determining what we need to measure in the future. In the case of observing systems, the models can be used for siting nodes and for determining what sensors are needed at each node. Report of working group 2. Pershing (Rapporteur), Mountain, Gangopadhyay, Bisagni, Brunner, (Insert Pershing's report here). Final Topics After the working group reports were presented, the time-frame of the next meeting was discussed. It was agreed that meetings be held at 6 month intervals, since the 2-year time frame of phase 4 is so short. The next meeting will be held in April 2006. The possibility of future publication in a volume of Progress in Oceanography brief discussion about 7. Meeting Summary The Phase 4B meeting successfully accomplished its goals. Remarkable progress already has been made on the projects even though funding was received recently in many cases. Each group gave clear presentations of their project goals and progress. The interactions between groups were invaluable and established early-on a working relationship between groups. The group of 4B researchers is well poised for the major synthesis work ahead. The results from these studies will contribute to a broad understanding of the effects of local and remote forcing on ecosystem and population dynamics of the target species. While the focus of the phase 4B research is primarily on scientific questions, this research is being done with consideration for transitioning results and models to operational tools useful to management.