Under natural conditions, the long-spined sea urchin, Diadema antillarum is the most important herbivore on Caribbean coral reefs and is therefore considered a keystone species. However, a disease in the 1980s caused the death of an estimated 98% of individuals throughout the region. This mass mortality event had a devastating effect on reef health, driving subsequent phase shifts to algal dominated benthic communities. Recovery has been extremely limited, with populations on most reefs still severely depleted, and Utila Island is a classic example of this. Remarkably, the Banco Capiro reef system in Tela Bay has a population density of D. antillarum at astonishingly high levels. It also boasts extremely high benthic reef health, despite historical overfishing leading to a complete collapse of the fishery. Since its recent discovery, Operation Wallacea scientists began detailed population studies in 2013 and this project will continue to build on this. The primary objective is to quantify changes in the abundance, biomass and population structure of D. antillarum on the reefs of Utila and Banco Capiro. Further data will assess the potential roles of competition, predation and environmental factors in driving the recovery on Banco Capiro.
In the Caribbean, there are a number of core issues that have been affecting the biodiversity of the coral reefs – including the mass mortality of keystone sea urchins that have allowed algal colonisation of reef areas, an invasive species originally from the Indo-Pacific (lionfish) that acts as a predator on reef fish which has been spreading across the Caribbean, and overfishing of reef fish by local communities. Opwall has two monitoring sites in Honduras: one is on the island reefs of Utila and the second on the coastal barrier reef of Tela. At both sites, teams of Opwall scientists and students collect annual monitoring data to assess temporal patterns of ecosystem change, alongside novel research to address key management priorities and gaps in our current understanding of tropical marine coastal ecosystem function.
Our marine sites are hot and usually dry, but with occasional storms.
Fitness level required
Low. Some fitness is required for in water activities, but conditions are relatively easy.
Facilities are comfortable but basic. There is phone signal and limited wifi that is often unreliable.