Project: Collaborative Research: modifiers of ocean acidification effects on top-down control in eelgrass habitat

NSF Award Abstract:
Seagrasses are widespread ocean plants that perform valuable ecosystem services, such as providing habitat for animals, slowing shoreline erosion, and sequestering carbon dioxide. This project investigates how changing ocean conditions (ocean acidification and nutrient pollution) affect growth and survival of eelgrass, the world's most widespread seagrass species. The project supports training for undergraduate students and graduate students at two Hispanic Serving Institutions through student exchanges and incorporation of the research into undergraduate courses and an immersive marine science semester. The results of this research, which inform preservation and restoration of seagrasses, are being shared with local resource managers.

Global stressors like ocean acidification (OA) act on organisms within the context of local environmental conditions. To fully understand how stressors influence marine species, it is essential to test how stressors interact with local factors to mediate ecosystem functions, particularly in foundation species (e.g. seagrasses, corals) whose degradation and loss has widespread effects on ecological communities. The principal investigators of this project are using eelgrass (Zostera marina) and its associated epibiota as a model system to test how the effects of OA on animal-plant linkages are influenced by two factors that vary among and within estuaries: nutrient stress and habitat structural complexity. These linkages involve a key mutualistic relationship between eelgrass and crustacean and molluscan epifauna, in which epifauna feed on fast-growing algae that can overgrow and kill eelgrass leaves, particularly when nutrient pollution is high. The PIs specifically are focusing on how OA and nutrient stress interactively alter epifaunal herbivory and trophic cascades in which predators indirectly drive eelgrass growth and mediate competition between eelgrass and epiphytic algae. The results advance knowledge of the effects of changing ocean conditions on ecological interactions.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.