In April, Kerim Aydin cochaired the Comparative Analysis of Marine Ecosystems (CAMEO) End-to-End Ecosystem Modeling Workshop in Woods Hole, Massachusetts. This workshop brought together over 40 researchers from NOAA, the National Aeronautics and Space Administration, and multiple academic institutions to discuss and compare methodology for developing end-to-end ecosystem models.
End-to-end marine ecosystem models are those that include ocean physics and plankton dynamics and explicitly model food web connections to fish, marine mammals, and humans. The workshop focused on model evaluation methods, such as data assimilation and model forecast skill assessment.
By Kerim Aydin
International Stock Production Modeling Workshop
In May, REEM ecosystem modelers participated in the international Stock Production Modeling Workshop funded through the CAMEO program. The workshop, led by Bern Megrey (AFSC) and Jason Link (Northeast Fisheries Science Center), was held in Woods Hole, Massachusetts, from 10 to 14 May 2010. Fifteen U.S. scientists from the NMFS Alaska and Northeast Fisheries Science Centers, the Universities of Washington, Maryland, Rhode Island, and Alaska worked together with seven Canadian and three Norwegian colleagues to assemble data on eight ecosystems for comparisons using production modeling methods.
The ultimate goal of the comparisons is to elucidate how three types of drivers—fishing, feeding, and physical environment—interact to affect ecosystem production. In advance of the workshop, REEM researchers Sarah Gaichas and Kerim Aydin provided time series data for all major groundfish species in the Gulf of Alaska and eastern Bering Sea, as well as diet matrices from the food web models for those ecosystems. They also contributed background presentations on the Gulf of Alaska ecosystem and methods for fitting ecosystem models to time series data. Buck Stockhausen and Teresa A’mar (Status of Stocks and Multispeces Assessment Program) contributed background presentations on the Bering Sea ecosystem and environmental time series for the Gulf of Alaska. Each participant is also contributing to one or more of the ongoing projects described below.
During the workshop, data from Gulf of Alaska and eastern Bering Sea ecosystems was compared with data from the Straight of Georgia ecosystem in the northeast Pacific, the Gulf of Maine/Georges Bank, Scotian Shelf/Bay of Fundy, Labrador/Newfoundland, and Gulf of St. Lawrence ecosystems in the northwest Atlantic, and the Norwegian/Barents Sea ecosystem in the northeast Atlantic.
Four projects were initiated at the workshop. First, the data from all of the ecosystems were categorized into a common aggregation framework encompassing habitat, feeding, taxonomic, and life history type guilds, and a database with information from all eight ecosystems was assembled. Second, a multispecies surplus production model was used to determine the potential consequences of applying several different aggregate biological reference points to a simulated fish community with known productive capacity and species interaction terms. Third, single species surplus production models were fit to data for the same or similar species across the ecosystems to compare estimated surplus production and examine the effects of physical covariates and species interactions for those species across the ecosystems. Finally, aggregate surplus production models were fit to summed data for all species within several ecosystems to examine differences in ecosystem-level surplus production.
The workshop was extremely productive and significant progress was made on all four projects in just a week. Workshop participants have submitted abstracts to present results at four international conferences in 2010, with many more expected in future years. Multiple peer-reviewed publications were outlined at the end of the workshop with contributions from all participants to be submitted in the next year.
