Millennial-scale change on a Caribbean reef system that experiences hypoxia Academic Article uri icon

abstract

  • Coastal hypoxia has become an increasingly acknowledged threat to coral reefs that is potentially intensifying because of increased input of anthropogenic nutrients. Almirante Bay (Caribbean Panama) is a semienclosed system that experiences hypoxia in deeper waters which occasionally shoals onto shallow coral reefs, suffocating most aerobic benthic life. To explore the longterm history of reefs in the bay we extracted reef matrix cores from two reefs that today experience contrasting patterns of oxygenation. We constructed a 1800yearlong record of gastropod assemblages and isotope compositions from six UTh chronologicallyconstrained reef matrix cores. We extracted two cores from each reef at 3 m water depth and two additional cores from a deeper part (4.8 m) of the hypoxiaexposed reef. Results show that the deeper part of the hypoxic reef slowed in growth and stopped accreting approximately 1500 years BP while the shallow part of the reef continued to accrete to the present day, in agreement with a model of expanding hypoxia at this time. Our proxybased approach suggests that the patterns of increasing herbivores and decreasing carbon isotope values in the deeper part of the hypoxic reef may have been driven by an increase in hypoxia via eutrophication caused by either natural changes or human impacts. Similar patterns in these paleoindicators occurred in the shallow part of the hypoxic reef during the last few decades. This suggests that the deep water hypoxia may be expanding to depths as shallow as 3 m and that shallow reefs are at greater risk due to increased human activity.

published proceedings

  • ECOGRAPHY

altmetric score

  • 52.95

author list (cited authors)

  • Figuerola, B., Grossman, E. L., Lucey, N., Leonard, N. D., & O'Dea, A.

citation count

  • 3

complete list of authors

  • Figuerola, Blanca||Grossman, Ethan L||Lucey, Noelle||Leonard, Nicole D||O'Dea, Aaron

publication date

  • September 2021

publisher