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NSF Biological Oceanography: Collaborative Research: Global-Pan Regional Synthesis: End-to-end energy budgets for US GLOBEC regions.

Start date: September 2008

This project is utilizing a combination of modeling and data analysis to compare trophic structure and food web energy flows among the four U.S. GLOBEC regions: Georges Bank, Marguerite Bay (Antarctic Peninsula), Northern California Current, and Coastal Gulf of Alaska. An end-to-end modeling approach is providing insights into how lower trophic level production is transferred to fish and other top predators. Comparison of biomass ratios at lower trophic levels is providing independent insights into trophic structure and its variation among the regions.

Diagram of the Antarctic food web.

NSF Biological Oceanography: Planktonic interactions in a changing ocean: Biological responses of Emiliania huxleyi to elevated pCO2 and their effects on microzooplankton (with M.B. Olson and B. Love).

Start date: January 2010

We have developed a system for regulating the carbon dioxide concentration in semi-continuous cultures of the coccolithophore Emiliania huxleyi. Experiments are underway to determine the effects of elevated pCO2 on E. huxleyi morphology and physiology. We are also investigating the influence of elevated pCO2 on the microzooplankton predators of E. huxleyi, including ciliates and dinoflagellates. Experiments are examining direct effects of elevated CO2 on microzooplankton growth and feeding rates, as well as indirect effects through alterations in prey quality. Our overall goal is to understand the effect of elevated CO2 on lower trophic level interactions, with a focus on microzooplankton predation.

Emiliania huxleyi photo by M.B. Olson

NSF Biological Sciences/Biological Oceanography: Collaborative Research: Constitutive and inducible predation defenses in cyanobacteria (with B. Palenik and B. Brahamsha).

Start date September 2010

In this project we are employing a combination of experimental, molecular, and field observational approaches to examine defenses against predation in the marine cyanobacterial genus Synechococcus. At Shannon Point, our focus is on the role of cell surface proteins in providing a defense against various protist grazers. With B. Brahamsha, we are using genetic mutants to specifically examine this role. Additional field sampling is providing insights into Salish Sea Synechococcus population dynamics. Our long-term goal is to understand how selective pressures exerted by predators influence the evolution, diversity, and abundance of natural Synechococcus populations.

Heterotrophic dinoflagellate with ingested Synechococcus.

North Pacific Research Board: The role of cross-shelf and along-shelf transports as controlling mechanisms for nutrients, plankton and larval fish in the coastal Gulf of Alaska (with R. Hopcroft, J. Napp, A. Matarese, C. Mordy, P. Stabeno).

Start date October 2010.

This field oceanography project is part of the larger Gulf of Alaska Integrated Ecosystem Research Program. The program as a whole seeks to understand factors influencing the year-one survival of 5 commercially important groundfish species, including walleye pollock, Pacific cod, Pacific ocean perch, arrowtooth flounder, and sablefish. For our lower trophic level component, field campaigns in multiple years are comparing physical oceanographic conditions, nutrient availability, and plankton (including larval fish) communities on the continental shelves of the eastern and western Gulf of Alaska. Our SPMC laboratory group is studying the phytoplankton and microzooplankton communities in these regions, including species composition, biomass, and the photosynthesis – irradiance response of the phytoplankton.

Heterosigma akashiwo ecology in the Salish Sea. (with S. Menden-Deuer)

Although unfunded at present, we continue to investigate the fish-killing raphidophyte alga Heterosigma akashiwo and its relationship to the ecosystem of the Salish Sea. Recently we added new (2011) H. akashiwo isolates to our collection, which now includes isolates from most years since the large-scale bloom year of 2006. We have also isolated a dinoflagellate predator similar to Stoeckeria algicida, which can survive and grow on H. akashiwo alone. Analyses of the role of salinity in regulating H. akashiwo predator-prey interactions are on-going.

H. akashiwo bloom off of Shannon Point Marine Center.