Intertidal Distribution Patterns of Zoanthids Compared to their Scleractinian Counterparts in the Southern Caribbean

Zoanthids are integral components of coral reef benthic communities in the southern Caribbean. Although reef-building scleractinian corals are important in providing the foundational structure of coral reefs, the dynamic nature of current trends in climate change will definitely affect cnidarian distribution and may promote competitive hardier species to increase in their abundance and distribution on coral reefs. Currently, two common zoanthid sp. (Palythoa caribaeorum and Zoanthus sociatus) are distributed more in some zones than others when compared to their reef-building cnidarian counterparts. The distribution of zoanthids was assessed for 2008 and 2012 in four horizontal intertidal zones using the line and point transect method. Intertidal scleractinian and zoanthid cover was 16.8 and 36.7%, respectively in 2008, compared to scleractinian (17.2%) and zoanthid cover (48.7%) in 2012. Distribution of zoanthids significantly increased in zones 2 and 4 from 2008-2012, as a result of increased coverage for Z. sociatus and P. caribaeorum respectively. Scleractinian coverage change was negligible in all zones, compared to increased zoanthid coverage, especially in zones 2 and 4 in 3.5 years. This study provides the first quantitative zoanthid distribution data over a short time period illustrating the dynamic changes in distribution favoring zoanthids over their more famous scleractinian benthic components of coral reef communities.