Sun coral regeneration after management actions in a Brazilian no-take marine protected area
摘要
Sun coral species of Tubastraea spp. are invasive on the Brazilian coast. Management actions have taken place in certain no-take marine protected areas (MPAs) where colonies are removed by skilled divers using mechanical methods. Sometimes, the available tools fail in removing the entire colony from the substrate, and remaining tissue may regenerate. This study evaluated tissue regeneration of Tubastraea spp. colonies in the Alcatrazes MPA, where a management program has been conducted since 2013. Vertical rocky reefs were monitored by photo-quadrats over 398 days. Total tissue survival was evaluated at the end of the study and a subset of three left tissues from each quadrat was monitored almost monthly to measure size variation (total area and number of polyps). Overall, survival of the remaining tissues was 90% and these tissues gave rise to colonies with 1–31 polyps. At the end of the study, 71% of the surviving colonies had reached the minimum colony size that is usually removed (i.e., bigger than five polyps). On average, total area increased by approximately 2 cm2/year and seven new polyps were developed per colony. Our research brings up the role of tissue regeneration in the recovery by sun corals of managed areas. Until new techniques are developed to avoid remaining tissue of sun coral, sublethal effects (e.g., lower growth, delayed reproduction, low fecundity and larval quality) on regenerated colonies may still be a beneficial outcome of management actions that deserve further investigation.