Benthic communities at the marine protected area Namuncurá/Burdwood bank, SW Atlantic Ocean: detection of vulnerable marine ecosystems and contributions to the assessment of the rezoning process

Abstract

The objectives of the present study were to characterize the benthic invertebrate communities at the Marine Protected Area (MPA) Namuncurá/Burdwood bank (created by the National Law 26875, year 2013) and their different sub-areas, to compare these benthic communities with nearby sub-areas, and to detect sites that meet the criteria of Vulnerable Marine Ecosystems (VMEs) to highlight the importance of this particular and rich sub-Antarctic region. We used quali- and quantitative data obtained from research cruises developed by Argentina in 2016 and 2017. The results showed that Porifera was the most important component (in terms of wet biomass) of these benthic communities, followed by Cnidaria and Echinodermata. The evidences regarding general composition of the main taxonomical groups of the benthic invertebrate community did not support the maintenance of the original zoning of the MPA (core, buffer, and transition), considering that only a weak differentiation was found among the sub-areas designed in the creation Law. Additionally, the analyzed evidences also demonstrated that this MPA was different from other neighboring areas. Vulnerable and fragile organisms recorded in many locations led to the detection of fourteen sites located inside the MPA Namuncurá that meet the characteristics of VMEs (wet biomass of ≥ 10 kg 1200 m−2 of vulnerable and fragile species). These evidences reinforce the conservation value of these particular and susceptible sub-Antarctic benthic communities, composed of both Antarctic and Magellanic species.