As a member of the inter-agency Bermuda Lionfish Taskforce, and the principle investigator of a study funded in 2013 by the Darwin Plus award, Goodbody-Gringley is using technical diving, population demography, and molecular biology to better understand the epidemic of voracious lionfish in Bermuda.
Lionfish are native to the Indo-Pacific, but in the mid 1980s people released a few lionfish into Florida’s coastal waters. Since then their descendants have invaded the Gulf of Mexico, the Caribbean, and the shores of the mid-Atlantic region of the United States. The consequences for these ecosystems have been disastrous, since lionfish have no natural predators in the Atlantic and gorge themselves on unsuspecting fish. In their native Pacific habitats lionfish have several predators and robust competition from other fish, which keep them to densities of 80 fish per hectare; by comparison, some shallow sites in the Bahamas have 390 lionfish per hectare and the impact of lionfish at these densities has been devastating. Divers in the Bahamas recorded a single lionfish devouring 20 reef fish in a half hour, and one study conducted over two months documented lionfish reducing the number of small and juvenile reef fish by 90 percent.
The first lionfish documented in Bermuda was a juvenile collected in a tide pool on the southern shore in 2000. Within four years, lionfish were ubiquitous in Bermuda. Now, Goodbody-Gringley’s surveys have revealed the lionfish invasion is more extensive than previously understood. Lionfish densities increase with depth and by 200 feet, the deepest sites surveyed, the average density of lionfish was 350 fish per hectare.
The recently discovered lionfish “hotspot” habitats will be characterized physically and chemically to better understand what conditions constitute favorable habitats for lionfish in Bermuda, and lionfish DNA will be sequenced to determine whether different shallow and deep water “hotspots” are isolated or interbreeding. The data generated from these studies will inform the government’s culling program and help shape long-term deep-water control strategies to protect Bermuda’s reef ecosystems.