Competitive interactions between corals and Trididemnum solidum on Mexican Caribbean reefs

The ascidian Trididemnum solidum competes for space on Caribbean reefs and is capable of overgrowing live scleractinian corals. From 2006 to 2009, we monitored over 30,000 coral colonies and quantified competitive interactions with this ascidian at four reef sites along the Mexican Caribbean. The total number of competitive interactions increased in time, but the mean percentage of coral colonies involved in interactions remained lower than 1% in all reefs. Bottom cover by T. solidum was also low (mean < 0.5%) in all reef sites in all sampling years. We conclude that during the temporal scope of our study, the overall potential effect of T. solidum on the dynamics of Mexican Caribbean coral populations was minimal.