Fish/Habitat Interactions
Structured coastal habitats—marshes, seagrass beds, and oyster reefs—provide a number of ecosystem services to coastal regions. The interaction between the physical habitats and the organisms that live there, especially fish, is the focal point of our research. We also work in pelagic habitats, looking at ecosystem properties that make for good growth or survival opportunities.
While our focus is on fish ecology, we have looked extensively at seagrass and tidal marsh habitats to better understand the complex matrix of plants comprising these structured habitats.
Dr. Sobocinski's dissertation research focused on fish use of seagrass habitats, especially as a nursery area. In addition to basic community ecology, she evaluated foodweb interactions and fish production in eelgrass (Zostera marina) habitats of lower Chesapeake Bay. She constructed an end-to-end foodweb model using Ecopath (a commonly used fisheries ecosystem model) as a model platform, to address questions regarding energy flow from the plants up through top predators in this system.
Underlying this model was an extensive field sampling program to gather data on abundances, production, and trophic interactions among species.
As managers desire an understanding of the value of habitats for species of concern, we are interested in how particular habitats are contributing to coastal fish production. As part of Dr. Sobocinski's research, she showed considerable seasonal biomass export from eelgrass habitats via an abundant, small mid-trophic-level fish, Bairdiella chrysoura (Sobocinski and Latour 2015).
This ecosystem subsidy had been previously overlooked and shows the importance of seagrass habitats not just for resident species, but also for mobile organisms, such as this fish, that are exporting seagrass-derived production to adjacent systems. We hope to invetsigate similar energy subsidies here in the Salish Sea.
For Dr. Sobocinski's post-doctoral research at OSU, she investigated juvenile flatfish use of the coastal shelf. This project was in collaboration with NOAA-Fisheries, Northwest Fisheries Science Center.
Many species of flatfish are commercially important along the Oregon coast, but relatively little is known about their ecology during their juvenile life history stage. This project aimed to better understand juvenile demersal fish community ecology and response to environmental drivers, specifically hypoxia.
We found that while depth was the strongest structuring variable, temperature and dissolved oxygen concentration also explained variation in fish distribution and abundance. The interaction of multiple stressors will be an important continuing area of research, especially with general warming in the North Pacific and other impacts of climate change in the Salish Sea.
Prior to her doctoral work, Kathryn conducted a number of fish-habitat interaction studies in the Columbia River estuary. The Columbia River possesses one of the largest stretches of tidal freshwater habitat in the world, although it had been little studied.
She investigated how juvenile salmon from different stocks use shallow water tidal habitats on their migration to the ocean.
Many of these vegetated habitats have been impaired or lost due to human activities and understanding the impacts to the species they support is important to understanding ecosystem dynamics and in determining what is limiting recovery of endangered or threatened species.