Examining the Effects of Non-Native Seagrass Species on Sediment Chemistry in Jobos Bay, PR.
Disciplines
Environmental Chemistry | Environmental Indicators and Impact Assessment | Environmental Monitoring | Environmental Sciences | Natural Resources and Conservation | Oceanography
Abstract (300 words maximum)
Seagrasses provide a variety of essential ecosystem services such as erosion prevention, carbon storage, processing water column nutrients, and providing food and habitat for endangered species. These services are invaluable to humans and must be studied to determine how seagrasses may be a link in achieving the overall goal of fighting climate change and preserving earth’s coastal and marine ecosystems. Jobos Bay, Puerto Rico hosts a wide variety of marine habitats but is vulnerable to ecosystem damage from human activities. This research was conducted to investigate how the presence of non-native Halophila stipulacea impacts the nitrogen cycle, nutrient availability, and dissolved ammonium pool in Jobos Bay. In March 2023, a total of forty-eight sediment cores were collected from four different habitat types across three different locations in Jobos Bay. Porewater was extracted from the cores and will be examined spectrophotometrically to determine porewater ammonium concentration and exchangeable ammonium concentration. An analysis of variance will be used to compare the concentrations of ammonium among the different habitat types. Due to higher refractory carbon composition in the biomass of Thalassia testudinum, more burial and less decomposition is expected in seagrass beds containing T. testudinum than those with H. stipulacea. I predict that this lower decomposition rate will be detected as lower sediment porewater ammonium concentration. Differences in porewater ammonium concentration associated with these species could indicate changes in the availability of nitrogen for microbial metabolism and nitrogen recycling within the ecosystem.
Academic department under which the project should be listed
CSM - Ecology, Evolution, and Organismal Biology
Primary Investigator (PI) Name
Troy Mutchler
Additional Faculty
Angel Dieppa, adieppa@drna.pr.gov
Examining the Effects of Non-Native Seagrass Species on Sediment Chemistry in Jobos Bay, PR.
Seagrasses provide a variety of essential ecosystem services such as erosion prevention, carbon storage, processing water column nutrients, and providing food and habitat for endangered species. These services are invaluable to humans and must be studied to determine how seagrasses may be a link in achieving the overall goal of fighting climate change and preserving earth’s coastal and marine ecosystems. Jobos Bay, Puerto Rico hosts a wide variety of marine habitats but is vulnerable to ecosystem damage from human activities. This research was conducted to investigate how the presence of non-native Halophila stipulacea impacts the nitrogen cycle, nutrient availability, and dissolved ammonium pool in Jobos Bay. In March 2023, a total of forty-eight sediment cores were collected from four different habitat types across three different locations in Jobos Bay. Porewater was extracted from the cores and will be examined spectrophotometrically to determine porewater ammonium concentration and exchangeable ammonium concentration. An analysis of variance will be used to compare the concentrations of ammonium among the different habitat types. Due to higher refractory carbon composition in the biomass of Thalassia testudinum, more burial and less decomposition is expected in seagrass beds containing T. testudinum than those with H. stipulacea. I predict that this lower decomposition rate will be detected as lower sediment porewater ammonium concentration. Differences in porewater ammonium concentration associated with these species could indicate changes in the availability of nitrogen for microbial metabolism and nitrogen recycling within the ecosystem.