New non-native ornamental octocorals threatening a South-west Atlantic reef. (24th September 2021)

• Record Type: Journal Article
• Authors: Menezes, N. M.; McFadden, C. S.; Miranda, R. J.; Nunes, J. A. C. C.; Lolis, L.; Barros, F.; Sampaio, C. L. S.; Pinto, T. K.
• Is Part Of: Journal of the Marine Biological Association of the United Kingdom. Volume 101:Number 6(2021)
• Page Start: 911
• Page End: 917
• Publication Date: 2021-09-24
• Subjects: Brazil -- Briareum hamrum -- exotic species -- marine aquarium trade -- Sarcothelia -- soft corals; Biology -- Periodicals; Marine biology -- Periodicals; 578.77
• DOI: 10.1017/S0025315421000849
• Languages: English
• ISSNs: 0025-3154

Abstract

Abstract: Invasive species are leading to ecosystem changes and socioeconomic deterioration around the globe. In 2018, unknown soft corals were noticed forming a massive 'blue carpet' on a shallow reef environment at Todos os Santos Bay, South-west Atlantic. In this study we identified the species, quantified their distribution and abundance as a first step for baseline invasion monitoring, and discussed origin, vector and impacts on native competitors. Coral samples were identified based on morphology and a multilocus DNA barcode, and benthic structure was characterized using digital photoquadrats. Our results revealed two new harmful non-native octocorals in this tropical rocky reef, the 'blue polyps' genus Sarcothelia (Xeniidae), native to Hawaii but likely an undescribed cryptic species, and Briareum hamrum (Briareidae), native to the Indian Ocean. Sarcothelia sp. was the dominant taxon in the rocky reef (mean cover 23.66% ± 21.46), exhibiting high coverage as well in the sandy and patch reef habitats (15.83% ± 15.81), however, only three colonies of B. hamrum were found, all outside the sampling area. These octocorals were in physical contact with native benthic organisms, mainly with the most abundant group, but apparently avoid turf algae in sandy and patch reef habitats. We suggest that irresponsible marine aquarium releases likely introduced these species to Brazilian reefs. After identifying the aquarium trade as the main vector of octocoral introductions, we reinforce the importance of inspecting marine species importation and the urgent need to implement a government plan to mitigate invasive species' impacts on the natural reefs of Brazil.