All known clams of the Lucinidae family harbor chemosymbiotic bacteria that fix carbon and supply it to their hosts in the absence of sunlight. Because lucinids are very abundant in shallow marine sediments, their effects on porewater composition, nutrient suspension, sediment biogeochemistry and vegetation productivity are considerable. However, their roles in sediment N and methane cycling are unknown, especially compared to other chemosymbiotic systems in deep-marine settings. Moreover, it is unclear how a decline in lucinid populations and/or functional diversity may impact coastal biome and ecosystem services, or even what could lead to lucinid population declines overall. This project will investigate the underexplored genetic, taxonomic, and functional diversity of lucinid chemosymbioses in shallow marine environments ranging from pristine to highly altered. Sampling will take place in Florida, California, and The Bahamas. The investigators will also test for ways to characterize lucinid-bacteria biodiversity in the geologic past. This research is expected to fill gaps in our understanding of lucinid chemosymbiotic systems, including how gene expression is altered for lucinids and their endosymbionts in changing ecosystem conditions, particularly due to anthropogenic impact.
This research will fill a major gap in understanding lucinid biodiversity loss that may occur in habitats sensitive to natural and anthropogenic disturbances and will be important for coastal resource management decisions. The researchers will provide interdisciplinary training in geochemistry, microbiology, and paleobiology to graduate and undergraduate students, including field studies in The Bahamas, training in museum collection standards, laboratory research, and computational bioinformatics. Students from underrepresented STEM groups will be involved on the project, and involvement with university outreach and mentoring programs will target symbiosis and biodiversity topics through formal and informal classroom, public speaking opportunities, and museum activities.
