Submission Type
Poster
Abstract
The Pliocene-Pleistocene extinction was responsible for the loss of ~70% of the carnivorous snails in the Atlantic-Gulf Coast region. A loss of carnivorous snails should be reflected in the occurrence of predation on bivalves. This project aims to analyze evidence of predation in microbivalves sampled from twelve different localities in Graham’s Harbor, one at French Bay, and one at Victoria Hill to determine if there is predation variation between facies as compared to an extinction event. Microbivalves were chosen to be studied because they are easier to collect and reflect the entire population. Each sample location was approximately four meters deep and varied between sand flats and grass flats. Sand was collected on a 0.125 mm sieve. The first 30 specimens less than 3 mm in length were selected for analysis. Microbivalves with evidence of predation (drill holes) by gastropods were recorded. Sand-flat environments had the highest average percent predation (21.9%-3.2%, average 11.6% predation; six total samples) as compared to grass-flats (15.6%-3.2%, average 9.2% predation; eight total samples). The percent of bivalves with evidence of predation varies within each facies from sample to sample, but does not, on average, vary significantly between facies. Thus, facies changes in Graham’s Harbor do not represent the profound change in fauna as seen in the Pliocene-Pleistocene extinction.
Recommended Citation
Alfiero, Sarah, "141-Predation on Microbivalves in Graham’s Harbor, San Salvador Island, The Bahamas" (2024). GREAT Day Posters. 35.
https://knightscholar.geneseo.edu/great-day-symposium/great-day-2024/posters-2024/35
141-Predation on Microbivalves in Graham’s Harbor, San Salvador Island, The Bahamas
The Pliocene-Pleistocene extinction was responsible for the loss of ~70% of the carnivorous snails in the Atlantic-Gulf Coast region. A loss of carnivorous snails should be reflected in the occurrence of predation on bivalves. This project aims to analyze evidence of predation in microbivalves sampled from twelve different localities in Graham’s Harbor, one at French Bay, and one at Victoria Hill to determine if there is predation variation between facies as compared to an extinction event. Microbivalves were chosen to be studied because they are easier to collect and reflect the entire population. Each sample location was approximately four meters deep and varied between sand flats and grass flats. Sand was collected on a 0.125 mm sieve. The first 30 specimens less than 3 mm in length were selected for analysis. Microbivalves with evidence of predation (drill holes) by gastropods were recorded. Sand-flat environments had the highest average percent predation (21.9%-3.2%, average 11.6% predation; six total samples) as compared to grass-flats (15.6%-3.2%, average 9.2% predation; eight total samples). The percent of bivalves with evidence of predation varies within each facies from sample to sample, but does not, on average, vary significantly between facies. Thus, facies changes in Graham’s Harbor do not represent the profound change in fauna as seen in the Pliocene-Pleistocene extinction.