College - Author 1
College of Science and Mathematics
Department - Author 1
Degree Name - Author 1
BS in Marine Sciences
Ryan Walter, College of Science and Mathematics, Physics Department
This study examines the temperature and salinity distributions in Morro Bay, a small, seasonally LIE located on the central coast of California. In Morro Bay, eelgrass (Zostera marina; a temperate seagrass), like all seagrasses, is a critical habitat-forming species that supports a large variety of invertebrate, fish, and bird species in the estuary (MBNEP, 2018). Since 2007, eelgrass in the estuary has declined by over 90%, with most losses occurring in the back regions (i.e., head) of the estuary (MBNEP, 2018). Near the mouth, eelgrass meadows have remained resilient, indicating that gradients in environmental conditions throughout the bay may be aiding or hindering eelgrass growth and survival. Previous work in the estuary during the summer dry season found that waters in the back-bay were hypersaline, hyperthermal, and decoupled from the mouth, resulting in long flushing times (the time to diffuse hypersalinity) in the back-bay regions (Walter et al. 2018). These findings were inferred from three discrete moorings spaced throughout the bay. This study develops a spatially resolved analysis of temperature and salinity distributions throughout the dry season, as well as estimates of diffusivities and flushing times using a salt budget balance approach. Additionally, the effects of evaporation on diffusivities and flushing times is explored. Increased spatial resolution and expanded analysis of evaporation rates may indicate the role that temperature and salinity 6 distributions play in ecosystem collapse or resilience and provide insight into the dynamics of other small to moderate-sized LIE estuarine systems.