Presentation Type
Poster
Presentation Type
Submission
Department
Biology
Major
Biology
Abstract
Coral reefs thrive in primarily oligotrophic environments, depending on factors such as temperature and salinity for their stability. While moderate levels of nutrients sustain coral growth, excessive nutrient inputs promote algal blooms which can outcompete corals for space. Over the past century, Maunalua Bay (O'ahu, HI) has experienced dramatic development and increase in population, which has affected the water quality in the nearshore coral reefs of the bay. The main source of dissolved land-based inorganic nutrients in Black Point is submarine groundwater discharge (SGD), which is a chronic freshwater vector that is enriched with nitrates, phosphates, silicates, and more. Because bacteria are fundamental members of coral reef ecosystems (serving roles in nutrient cycling, holobiont health, and reef stability), shifts in bacterial community composition can serve as great indicators of environmental stress. On healthy, coral-dominated reefs, microbial communities are typically characterized by Alphaproteobacteria, which are associated with diverse, low-virulence assemblages. As nutrient availability increases and benthic cover shifts toward algal dominance, these communities are expected to shift toward copiotrophic Gammaproteobacteria, including potentially pathogenic taxa such as Vibrio, Alteromonadales, and Flavobacteriales. To test this hypothesis, water samples were collected at Black Point, O'ahu, Hawai'i, from both benthic and surface levels across 25 sampling sites at different distances from a known SGD seep location. Given that SGD delivers chronic nutrient enrichment to nearshore reefs, we hypothesize that SGD acts as a driver of this microbial community shift in Maunalua Bay.
Faculty Mentor
Florybeth La Valle
Funding Source or Research Program
Keck Scholars Program
Location
Waves Cafeteria
Start Date
10-4-2026 1:00 PM
End Date
10-4-2026 2:00 PM
Included in
Submarine Groundwater Discharge as a Potential Driver of Bacterial Microbiome Shifts in Nearshore Coral Reef Ecosystems at Black Point, Maunalua Bay, Oahu
Waves Cafeteria
Coral reefs thrive in primarily oligotrophic environments, depending on factors such as temperature and salinity for their stability. While moderate levels of nutrients sustain coral growth, excessive nutrient inputs promote algal blooms which can outcompete corals for space. Over the past century, Maunalua Bay (O'ahu, HI) has experienced dramatic development and increase in population, which has affected the water quality in the nearshore coral reefs of the bay. The main source of dissolved land-based inorganic nutrients in Black Point is submarine groundwater discharge (SGD), which is a chronic freshwater vector that is enriched with nitrates, phosphates, silicates, and more. Because bacteria are fundamental members of coral reef ecosystems (serving roles in nutrient cycling, holobiont health, and reef stability), shifts in bacterial community composition can serve as great indicators of environmental stress. On healthy, coral-dominated reefs, microbial communities are typically characterized by Alphaproteobacteria, which are associated with diverse, low-virulence assemblages. As nutrient availability increases and benthic cover shifts toward algal dominance, these communities are expected to shift toward copiotrophic Gammaproteobacteria, including potentially pathogenic taxa such as Vibrio, Alteromonadales, and Flavobacteriales. To test this hypothesis, water samples were collected at Black Point, O'ahu, Hawai'i, from both benthic and surface levels across 25 sampling sites at different distances from a known SGD seep location. Given that SGD delivers chronic nutrient enrichment to nearshore reefs, we hypothesize that SGD acts as a driver of this microbial community shift in Maunalua Bay.