Area of research
Ecology · Oceanography
Research interest
Research topics from publications: Sea urchin mass mortalities 40 y apart further threaten Caribbean coral reefs; Brooding and parthenogenesis enhance the success of the coral Porites astreoides relative to Orbicella annularis. Representative work: In 1983 to 1984, a mass mortality event caused a Caribbean-wide, >95% population reduction of the echinoid grazer, Diadema antillarum . This led to blooms of algae contributing to the devastation of scleractinian coral populations. Since then, D. antillarum exhibited only limited and patchy population recovery in shallow water, and in 2022 was struck by a second mass mortality reported over many reef localities in the Caribbean. Half-a-century time-series analyses of populations of this sea urchin from St. John, US Virgin Islands, reveal that the 2022 event has reduced population densities by 98.00% compared to 2021, and by 99.96% compared to 1983. In 2021, coral cover throughout the Caribbe The abundance of many Caribbean corals has declined over the past few decades, yet now Porites astreoides is more common on many shallow reefs than in the 1980s and shows evidence of local adaptation. We compare the small-scale (1-8000 m) genetic structure of this brooding species and the broadcasting coral Orbicella annularis on reefs (<14 m depth) in St. John, US Virgin Islands, to examine how larval dispersal and asexual propagation contribute to the retention of genotypes within reefs. Populations of P. astreoides have genetic structure across reefs separated by a few 100 m, increased relatedness within reefs, and parthenogenetic larval propagation confirmed by parent-offspring genotypin