The ecological and economic value of coral reef fish communities makes them vital not only to ecosystem health but also to local food security and livelihoods. However, as consumers they are ultimately dependent on the abundance and composition of primary producers within the system, but also the provision of microhabitats for shelter. Competition for space on Caribbean reefs is extremely intense, with traditionally dominant hard corals increasingly being replaced in recent decades, primarily by macroalgae, but also soft corals and sponges. These phase shifts have significant impacts on benthic structure and function, with knock-on effects on dependent communities such as fish. Students on this project will conduct fish surveys on a range of reefs around Utila Island using cutting edge stereo-video technology, which allows not only abundance and diversity measurements, but also accurate biomass estimates from published species-specific
length: weight relationships. These data will be compared to benthic assessments using line intercept video transects and state of the art 3D computer modelling, to investigate how benthic health and structure impacts fish communities at the species, family and feeding guild level. With over five years of data already available, students can also incorporate a temporal component to explore long-term trends in benthic and fish community composition at key study sites.
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.