Barbados

Reef Ball Pilot Project in Hastings, Barbados

Reef Balls are artificial reef structures designed to create new or enhance existing reef habitats. They consist of a long-lasting marine concrete mix which allows for growth of benthic biota such as corals and a suitable habitat for fish. Previous observations suggest that they can also serve as fish recruiting devices, but much debate exists as to whether an increased presence of fish at reef ball locations is a result of direct recruitment or population redistribution (i.e. aggregation vs. production). The Barbados Marine Trust in 2004 deployed 30 Reef Balls off the South Coast of Barbados in a sandy channel located between two patch reefs. The pilot project sought to determine the propriety of reef balls for Barbados’ reefs, and to ascertain its effect on fish abundance, distribution and diversity at the test site and its reef environs. The Bohnsack and Bannerot Fish Census Method (1986) was employed which involves a survey of all fish observed within a water column 15m in diameter over a ten (10) minute period. This was executed several times over an 18-month period. Three neighbouring control sites (two reef sites, one sand site) were designated to be compared and contrasted against the experimental reef ball site. The overall observation findings indicate that the placement of the artificial reef structures into the barren location has resulted in an increase in both the abundance and diversity of fish within the same location – initially due to redistribution, but subsequently from direct recruitment. The reefs balls have also demonstrated marked stability in unstable water conditions (after the passage of Hurricane Ivan), proving that they can maintain high structural integrity in such conditions and thus can be used as shoreline defense mechanisms or for reef rejuvenation in high energy environs.