US GLOBEC Pan-Regional Synthesis Workshop Boulder, Colorado 18-21 February 2008

1. US GLOBEC Pan-Regional Synthesis Workshop Boulder, Colorado 18-21 February 2008 End-to-end Energy Budgets in US GLOBEC Regions University of Rhode Island Dian Gifford Jeremy Collie University of South Florida Kendra Daly Marina Marrari British Antarctic Survey Eugene Murphy Nadine Johnston Martin Collins H.T. Harvey & Associates David Ainley Woods Hole Oceanographic Institution John Steele NMFS/SWFSC Steven Bograd Oregon State University Jim Ruzicka University of Massachusetts, Dartmouth Jim Bisagni NMFS/NWFSC Ric Brodeur University of Alaska, Fairbanks Ken Coyle Old Dominion University Eileen Hofmann Tosca Ballerini NMFS/AFSC Kerim Aydin Anne Hollowed Sarah Gaichas Bob Foy Virginia Institute of Marine Science Walker Smith Woods Hole Associated Scientists Cynthia Tynan University of Western Washington Suzanne Strom USGS, Madison Chris Ribic University of Maine Andy Thomas

2. What is End-to-End ?? E2E - now a serious area of research with potential application to ecosystem management, including fisheries management Meaning of E2E - not always clear Science E2E: trophic web from bacteria to whales and humans Management E2E: science at the bottom end & management at the top

3. GLOBEC IS SPECIES-CENTRIC GLOBEC Physical Ocean Zooplankton- Fisheries focus Predators Life History Trophic level Without Life History Phytoplankton- Nutrient focus Chemistry Functional complexity DeYoung et al. 2004

4. Species-centric v. Trophic centric ** The approaches are complementary ** The approach used depends on the questions asked ** No single model integrates across trophic levels & provides taxonomic resolution WE USE GLOBEC SPECIES-CENTRIC DATA TO CONSTRUCT TROPHIC-CENTRIC FOOD WEBS

5. The Big Question Q: Is biological production controlled by bottom-up (i.e., climate) or top-down (i.e., fishing) processes? Q can be asked of any ecosystem, given sufficient data

6. Piscivorous fish Juvenile fish Benthivorous Planktivorous fish fish Carnivorous Carnivorous benthos plankton Suspension Deposit Meso- zooplankton - feeders feeders Feces Loss Micro- zooplankton Detritus Loss Loss Small phytoplankton Large phytoplankton Loss Loss Ammonia GENERAL APPROACH (GB) Upper web: -juvenile fish -3 fish feeding guilds -carnivorous ZP -carnivorous benthos Lower web: -nutrients -2 categories PP -detritus, feces -zp -mesoZP -DF+SF benthos -N recycling NO3

7. STUDY REGIONS Fig. 1. GLOBEC GB region. Figure 4. SO study region. LTER is Palmer Long-term Ecological Research (LTER) site., AMLR is US Antarctic Marine Living Resources (AMLR) region. These regions provide a continuum of data sets along the western Antarctic Peninsula. Filled circles are locations of current meter moorings for US SO GLOBEC field studies. Star is the intermediate ice edge study region. and South Georgia (SG) provides the downstream study region. MB is Marguerite Bay, BS is Bransfield Strait, GS is Gerlache Strait, and SG is South Georgia in the Scotia Sea.. Fig.2. NCC model domain Blue circles (spring), red circles (summer) GLOBEC & BPA pelagic trawl coverage, 2000. Fig. 3. Management areas included in the ecosystem models for the Eastern Bering Sea (EBS), (GOA) and Aleutian Islands (AI).

8. Regional Characteristics

9. Workplan-1 Task 1. Assemble/update E2E models for each region. The regions differ in hydrography, trophic structure and physical forcing. Initial requirement is for transportable data sets and end-to-end models for each region. We draw upon the species-centric data and models for each region to develop trophic-centric models (e.g. Steele et al. 2007).

10. WORKPLAN-II Task 2. Model Skill Assessment -provides guidance for model improvements -quantitative basis for cross-system comparisons -comparison with in situ data using a suite of statistical approaches of escalating rigor -evaluation of how well each model captures basic fluxes of e.g., primary production, secondary production and export production

11. WORKPLAN -III Task 3. Determination of diagnostics Model diagnostics are the primary end results of the entire project and permit cross-regional comparisons. Diagnostics common to all 4 regions. Diagnostics will be extracted from the regional models to evaluate effects of top-down (fishing pressure) and bottom-up (climate change) forcing across the 4 regions. Diagnostics not known in advance, but comparisons based on concentration or biomass are unlikely to be useful. Obvious candidate diagnostics are material fluxes, which avoid issues of among-region species and biomass differences. Potential candidate fluxes: primary production, mesozooplankton production, benthos production, and nutrient fluxes. Every diagnostic will not necessarily apply to all regions, e.g., macronutrient fluxes are less important for primary production in the SO than for GB. Among-model comparisons of diagnostics.

12. WORKPLAN-IV Task 4: Methods for among-model comparison of diagnostics. Diagnostics for the models in the different regions will be compared using quantitative methods that will be developed as part of this project. 0-order diagnostics: Descriptive comparisons of trophic structure across the 4 regions are the 0-order activity for this task. This can include statistical methods of comparison and quantitative measures of trophic or size structure. 1st-order diagnostics: Linear mass-balance and inverse methods will be used as beginning 1st-order comparisons while we investigate the use of approaches such as parameter optimization via variation adjoint methods in the four regions (e.g., Friedrichs et al. 2007). Linear and mass balance analyses can be based on existing top-down (ECOPATH), bottom-up (Inverse) or combined (Steele et al. 2007) approaches. 2nd-order diagnostics. Potential 2nd order methods involve dynamic simulation either as direct representation of parts of the web or perturbation analyses of mass balance solutions.

13. WORKPLAN- IV, continued The comparison approaches chosen rely upon estimation of similar processes in the 4 regions. Potential new production (PNP) is an example of a process common to all regions. PNP = the difference between the rate of change of “nitrate storage”, vertically-integrated between the surface and the depth of the euphotic zone and “nitrate vertical flux” into the euphotic zone (Bisagni 2003; Steele et al. 2007). We expect that this particular diagnostic will be more relevant for some regions (GB) than others (SO), but this type of calculation will allow us to quantify these differences. Data sets adequate for the calculation of PNP exist for each study region from historical data sources and GLOBEC program observations.

14. Responsibilities of scientific investigators

15. Once the E2E webs are constructed, We can ask other kinds of questions: Q: What happens to cod (or any target species) if we alter the food web? Q: How do altered nutrient inputs impact the upper web? Q: What happens if carnivorous ZP (jellies) are eliminated? Or bloom? Q: What happens if microzooplankton are reduced or increased? Q: Does reducing the flux of PP to the benthos affect the upper web? Etc………..

16. What does it take to construct end-to-end energy budgets for GLOBEC study regions? **Interdisciplinary expertise **Time series of biota, chemistry, physics, climate: the longer the better **Standing stocks of all trophic levels, not just target species **Rate measurements and transfer functions for all trophic levels, not just target species **Knowledge of physics and fluxes **$$$$$

17. Thank you With apologies that I can’t be at the workshop --- Dian