Marine litter and wood debris as habitat and vector for the range expansion of invasive corals (Tubastraea spp.)

Abstract

Tubastraea coccinea Lesson, 1830 and T. tagusensis Wells 1982 are azooxanthellate corals non-native to Brazil and introduced through fouling on oil platforms, the primary vector. They first invaded the tropical rocky reefs at Ilha Grande Bay (southwest Atlantic Ocean), during the early 1990s. Currently, at some Brazilian locations these species occupy 80% of the benthos of the shallow subtidal. They cause economic and environmental impacts by fouling shipping and modifying native communities. This study provides observations of an additional mechanism of secondary dispersal by T. coccinea and T. tagusensis that were seen attached to floating wood debris and marine litter, which are highly abundant in the region. Such rafting corals have been found adjacent to invaded reefs and stranded on beaches. These observations indicate that transport by rafting over long distances may be another mechanism of range expansion and secondary introduction of these invasive species within the region.