My research focuses on a variety of problems in biological oceanography and zooplankton ecology, particularly those related to how climate-driven environmental change interacts with biological processes to control zooplankton biogeography, diversity, community structure, and abundance. Interactions between the environment and zooplankton population structure, behavior (e.g., diel vertical migration), and growth ultimately control ecosystems including fish and other upper trophic level organisms. I work on these interdisciplinary projects using a combination of field collections, laboratory experiments, satellite data and collaboration with modelers.

The Puget Sound Zooplankton Monitoring Program

See the program and many of our partners featured in a production by the Puget Sound Partnership:

Read more below and at Making Waves: Stories From the People Protecting and Recovering Puget Sound.

Current research projects:

Completed projects:

  • Quantifying juvenile salmon prey quality and exploring trophic linkages in Puget Sound.
    • With Michael Brett (UW CEE) and Minna Hiltunen (University of Eastern Finland), we are studying the dietary quality of juvenile salmon prey to gain insight into the lower trophic level food web of Puget Sound and how changes in zooplankton lipid composition affects juvenile salmon growth. We are quantifying the fatty acid content and composition and caloric content of key zooplankton taxa to characterize their biochemical makeup.
  • Consequences of hypoxia to food web linkages in a pelagic marine ecosystem.
    • In collaboration with T. Essington, J. Horne, S. Parker-Stetter, M. Sato (UW School of Fisheries) and L. Li (DFO Canada), we examined the effects of hypoxia on species composition, distributions, and predator-prey interactions between zooplankton and fish by combining acoustics and direct (net) sampling with bioenergetic modeling of energy flow. We will link observed distributional and compositional shifts in mesozooplankton and fish to pelagic food web energy flux. click here for the project summary from the NSF proposal
  • Effects of ocean acidification on copepod populations mediated by changes in prey quality.
    • We collaborated with Drs. Brady Olson and Brooke Love at the WWU Shannon Point Marine Center to measure the effects of biochemical changes in phytoplankton grown under CO2 levels on reproduction and growth of the copepods Calanus pacificus and Acartia hudsonica. click here for the project summary from the NSF proposal
  • Impacts of ocean acidification on early life stages of crustacean zooplankton. click here for more info.
    • In collaboration with NOAA/NWFSC (P. McElhany and S. Busch), we measured the effects of pH on the distribution and development of zooplankton and the resultant impacts on trophic webs.
    • Read about Karissa Lear's JISAO undergraduate internship project and watch a short video on her work! Karissa's page
  • GLOBEC / POBEX: Climate effects on zooplankton community composition and biomass in the northern California Current System.
    • Funded by NSF through the US GLOBEC program, a multi-disciplinary group of PIs and international collaborators (in Canada, Japan, and Chile) led by E. Di Lorenzo (GA Tech) studied climate influences on large-scale and regional ecosystem variability around the Pacific Ocean basin using a combination of circulation models, time series of in situ observations, and remote sensing. click here for more info
  • Modifying the molt-rate method of estimating stage-specific copepod growth rates.
    • We collaborated with Andrew Hirst (Queen Mary University of London) to develop and test a realistic method to measure copepod growth in the field. In summer 2010, we developed the new method and used it to measure stage C5 Calanus pacificus growth in Puget Sound.
  • Effects of near-bottom hypoxia on distribution and abundance of fish and zooplankton: implications for predator-prey interactions and the energy flow from zooplankton to fish.
    • In collaboration with John Horne, Sandy Parker-Stetter (UW School of Fisheries), and the Washington Department of Fish and Wildlife (WDFW), we conducted field surveys of fish and zooplankton using acoustics, zooplankton net tows, and purse seining in Lower Hood Canal, Puget Sound to examine the effect of chronic low dissolved oxygen concentrations on species composition and distributions of organisms. Manuscript coming soon! click here for a poster presented at the Salish Sea Ecosystem Conference
  • Effects of Washington continental shelf methane bubble plumes on aggregation and vertical distribution of euphausiids.
    • Using a combination of acoustics, ROV cameras, and zooplankton nets to study aggregations of euphausiids observed around bubble plumes. Manuscript on bubble movement published in Geosphere by undergraduate researcher Marie Salmi (congratulations Marie!).
  • Effects of mesoscale circulation on cross-shelf distribution of zooplankton and carbon cycling in the California Current System.