Long-term change in Caribbean coral reef ecosystems

By combining paleoecological, historical, and modern survey data, we are tracking long-term change in Caribbean reefs to inform conservation and restoration efforts. Our group assesses change in multiple ecosystem components (fish, corals, urchins, mollusks, benthic foraminifera, sponges) to pinpoint the causes and consequences of recent reef declines.

This work has yielded several critical insights into the mechanisms of Caribbean reef decline:

  • The human-caused transformation of Caribbean coral communities occurred via three major steps: (1) the initial loss of competitive Acropora corals from local human stressors in the 1950s and 1960s, (2) the replacement of Acropora corals with weedy and stress tolerant corals in the 1970s and 1980s, and (3) the loss of weedy and stress tolerant corals in the 1980s and 1990s from a combination of local stressors and climate change [Ecology and Evolution]
  • Caribbean Acropora corals began declining decades before climate change-related disease and bleaching outbreaks, and declines were related to local human stressors [Science Advances]
  • The loss of Acropora resulted in increases in disturbance-adapted corals until climate impacts reduced all corals regardless of life history strategy [Ecology and Evolution]
  • Prehistorical and historical declines in reef accretion rates were causally driven by a loss of parrotfish, likely from overfishing [Nature Communications]
  • The failure of the keystone herbivore urchin Diadema antillarum to recover since its 1980s mass mortality event may be due to an increase in its competitor, the three-spot damselfish, following the overfishing of predatory reef fishes [Ecography]
  • A historical increase in palatable sponges may be due to the historical overharvesting of sponge-eating sea turtles [Marine Ecology Progress Series]
  • Historical local human activities have unraveled reef ecosystem structure at a scale similar to past large-scale hydrological changes [Ecography]
  • Historical land clearing for banana agriculture caused declines in Acropora corals decades before climate change impacts in Caribbean Panama [Ecology Letters]
  • The contrasting ecological condition of reefs along the Caribbean coast of Panama can be explained by varying histories of human occupation in these areas [Marine Science Bulletin]

This work is in collaboration with Richard Norris, Aaron O’Dea, John Pandolfi, Ben GreensteinMary Donovan, Chelsea Korpanty, Geoff Cook, and Jeremy Jackson.

Recent fossils of mollusks provide insight into reef environmental change

parrotfish pharyngeal
To identify reef fish teeth fossils found in the sediment cores to taxonomic and functional groups, we built the first photographic reference collection for modern reef fish teeth.

Belize cores
Coring expeditions in Panama and Belize (photos by Aaron O’Dea)

elkhorn coral illustrationStaghorn coral illustration.

Threatened Caribbean elkhorn and staghorn corals from the Acropora genus (illustrations: NOAA)