LAUSR

The red porgy (Pagrus pagrus) is a carnivore bottom dweller sparid, inhabiting flat sandy bottoms, rhodolith and seagrass beds of the Mediterranean Sea, the Western Atlantic (from Florida to Argentina) and the Eastern Atlantic (from Britain to Gabon). Along its native range, the red porgy is highly targeted by commercial and artisanal fisheries, in the Mediterranean Sea is farmed due to rapid growth under intensive farming. In the past 40 years, population decline of this species has been widely reported. In many locations, such as in the Brazilian coast, stocks have collapsed. The central portion of the Brazilian coast harbors the largest rhodolith beds in the world and the highest levels of nektonic and benthic biodiversity. Along the rhodolith megahabitat, P. pagrus density is disproportionately higher (by 480%) than conspicuous benthic fishes inhabiting the same environment. Despite the ecological and economic importance of such important species along its native range, little is known regarding its habitat use, niche availability and population responses to global warming. Herein, we present habitat affinities based on data sampled using Baited Remote Stereo-Video Systems (BRUVS), and modelled niche availability and global warming populational responses. Our findings revealed that the red porgy is a species highly associated with rhodolith beds along the central portion of Brazilian coast. The presence of a disproportional density and biomass of the red porgy, compared to other marine fish species, indicate that the species play a key ecological role as a carnivore, mesoconsumer and prey/predator tolerant species, maintaining essential ecological functions in the habitat. In a global warming scenario, the model predicted populational niche shifts poleward and a severe niche erosion at lower latitudes as expected. Conservation initiatives (implementation of MPAs, trawling exclusion zones, mining exclusion zones, fisheries management policies) are urgent to secure future stocks of the red porgy and also preserve the fragile rhodolith beds where they inhabit. This article is protected by copyright. All rights reserved.