Herbivorous Fish: Key to Coral Reef Health in the Caribbean

Coral reef health relies on dynamic interactions among key functional groups of organisms. Disruptions to the roles these taxa play (fish, coral and algae) can lead to changes in community structure with negative implications for coral reef biodiversity. Algae is an important food source in reef systems but as an excellent competitor it can compromise coral larval recruitment. EVER SINCE Columbus arrived, reefs around the world have undergone changes, the current a phase-shift from coral to algal dominated systems is problematic. This relative overabundance of algae and loss of coral biomass and biodiversity may in some ways be reduced, or at least controlled, through healthy reef herbivore populations.

Herbivorous fish keep algae in check, helping to keep the system in balance to corals can thrive.This project will identify functionally important herbivores that maintain the balance between fishes and coral reef community structure as critical for protection. The outcomes will help us to understand which herbivorous species make the biggest contribution to maintaining the ecosystem balance and how we can protect them.

By looking at the characteristics of herbivorous fish across all three of the Cayman Islands, including understanding the quantity, size and their diet preferences, the project seeks to fully explore the role of herbivorous fish and their connectivity to the local reef ecosystem. The project will include tagging and mapping fish via acoustic telemetry to understand movement and ranges of the herbivorous fish populations, so a biodiversity action plan can be meaningfully recommended to government.

The project is supported by Darwin Plus Initiative, which provides grants for UK overseas territories that are rich in biodiversity, the Smithsonian, the Cayman Islands Department of Environment and private donors that support CCMI.