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US GLOBEC Before and After Eileen Hofmann Old Dominion University.

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Presentation on theme: "US GLOBEC Before and After Eileen Hofmann Old Dominion University."— Presentation transcript:

1 US GLOBEC Before and After Eileen Hofmann Old Dominion University

2 Outline of Presentation Understanding prior to GLOBEC Advances in understanding physical- biological interactions resulting from GLOBEC science Moving forward from what has been learned from GLOBEC

3 Pre-GLOBEC Recruitment to marine fish populations depended on Critical period - variations in larval feeding and nutrition >larval feeding was viewed in terms of a direct link from zooplankton to the consumer Aberrant drift - advection into favorable or unfavorable environmental conditions >the scales of the physical environment were known but the details of the scales that were relevant to the planktonic organism were essentially unexplored

4 Pre-GLOBEC Physical oceanography and biological studies were essentially separate disciplines >difficulties in attributing causes, effects and mechanism Studies restricted to a limited locations and short times >decadal and longer time variability not recognized as driving forces Lack of linkage and cohesion between the observational and modeling communities

5 Science Challenge To understand the dependence of marine population dynamics on the physical structure of the ocean and to link this to ecosystem dynamics (NAS, Steele et al., 1987) GLOBEC Goal “…. understand how climate change and variability will translate into changes in the structure and dynamics of marine ecosystems and in fishery production”

6 Scales of Processes View that marine ecosystems operate along a continuum defined by space and time underpinned much of the research that was undertaken during GLOBEC GLOBEC --> View has evolved to one in which marine ecosystem variability and population recruitment result from the integration of processes across all scales and includes direct as well as indirect interactions

7 Processes at all scales influence variability of marine organisms and populations Studies of marine ecosystems require integration of the environmental drivers and biological responses

8 Scales of Processes Pick out key scales and follow these through system Multiple optima in ecosystems and have begun to understand interactions that produce these

9 Scale of aggregation depends on view of system Scales of spatial variation

10 Scale of aggregations - exploited by different predators Krill are important to different parts of the food web because of a spatial structure that covers many scales Longevity and overwinter survival allows spatial and temporal transfer Makes energy available to predators Structure modifies the operation of the ecosystem

11 GLOBEC - Recruitment patterns Why patterns occur and what are key processes?

12 Knowledge of scale interactions have resulted in additional hypotheses about physical-biological controls on recruitment

13 Alternative food web structures Implications for production and maintenance of predators Understand the causes for change and key processes

14 Development of conceptual frameworks for recruitment that encompass multiple scales Development of field and modeling programs to test conceptual models of ecosystem structure and function

15 Modeling Physical-Biological Interactions Modeling is central to GLOBEC science Built on scientific and technological advances, such as realistic circulation models Integration of IBMs with circulation models resulted in ability to determine transport pathways, residence times, controls on growth Allowed identification of spawning areas, recruitment regions, connectivity of populations at a range of scales

16 Realistic Regional Circulation Models Coastal Gulf of Alaska West Antarctic Peninsula Include sea ice, coupling to atmospheric models and larger scale models Georges Bank

17 Advection Autochtonous – Allocthonous production Displaces production Disconnects Production - Mortality Production - Export

18 Connection between spawning and recruitment regions Inclusion of detailed biology provides process understanding Importance of comparative studies Population connectivity at regional to circumpolar scales Thorpe et al. (2007) Spiers et al. Tian et al. (2009) Speirs et al.(2006)

19 Physical-biological models evolved to systems of interconnected modules Developed around data sets from GLOBEC programs NEMURO - minimum trophic structure and biological relationships … thought to be essential in describing ecosystem dynamics in the North Pacific

20 Top down and bottom up controls operate simultaneously but relative effect of each is variable GLOBEC Target species Approach deYoung et al. (2004)

21 GLOBEC science evolved to include humans as part of the marine food web Importance of top predators including humans Perry et al. (2010) Barange et al. (2010)

22 Physical-biological Interactions GLOBEC Science Ecosystems result from interactions across multiple scales Comparative studies provide insights beyond those from single program Target species approach allowed picking out key processes - compare with other systems Top predators, including humans, are integral parts of food web Physical, biological, observational, and observational communities focused on integrated research programs

23 Climate/ JGOFS Heat Distribution/ Biogeochemistry Budgets/ Elemental cycles Weather/ GLOBEC Synoptic patterns/ Population dynamics Events/ Species Future Directions Next challenge Provide meaningful forecasts and projections of marine population variability and response to climate change and human impacts

24 Link regional and basin-scale models Expand beyond regional focus Methods for Down/Up Scaling of Physical-biological Models

25 Temperature warming and cod recruitment Fogarty et al. (2008) Climate Projections Ecosystem Responses

26 Relevance to Global Ecosystems Global carbon budget models lack biological detail Current models do not capture what is known about ecosystems and harvesting/human impacts

27 What Needed? Sustained observations that support predictions and forecasts Continued integration of observations and models from outset of programs Explicit inclusion of human dimension Estimates of uncertainty and communication of this to policy makers Educational outreach to public sector

28 Concluding Remarks GLOBEC science advanced state of models, data sets, and conceptual understanding of physical-biological interactions that underlie marine population variability Provides basis to develop the integrative research programs between the natural, social, and economic sciences that are needed to understand and sustain the world’s ocean in an era of increasing change and uncertainty


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