Spatio-temporal dynamics of the fish community associated with artisanal fisheries activities within a key marine protected area of the Southwest Atlantic (Uruguay)

Abstract

Exploitation of fish species within marine protected areas (MPA) requires knowledge about fish and fleets dynamics in order to provide reasonable management actions. Our study analyzes a multi-specific artisanal fishery (<10 TGR) operating from La Paloma port (Uruguay, South America) within the MPA of the Rocha Lagoon Protected Landscape (MPA-RLPL) through the temporal assessment (September 2005 to January 2010) of daily catch composition, fishing gear, and fish community dynamics. Seventeen vessels operated inside and outside the MPA-RLPL and they reached 202,773 kg of total catch within that MPA. This amount represents 9.1% of landings registered in La Paloma port during the study period (5 years). Following the seasonal dynamics of catch composition and fishing gears it was revealed a differential use of this coastal protected area by the artisanal fisheries and the fish community. Higher catches of Squatina guggenheim, Mustelus schmitti, Galeorhinus galeus, Urophycis brasiliensis, Paralichtys orbignyanus, and Cynoscion guatucupa occurred from spring-summer, whereas in fall-winter, the higher catches were composed of Micropogonias furnieri (adults and juveniles), Umbrina canosai, Pomatomus saltatrix, and Parona signata. A multiclass classification tree (CART) method confirmed the strong relationship between the catch composition, fishing gear, and time of fishing (month, season); this method successfully classified the dominant catches in 72% of the sets (error = 18%, n = 294). Squatina guggenheim (a threatened coastal shark), and Micropogonias furnieri (a overexploited bony fish) were the dominant catch in most fishing sets. At the present there are no specific measures to regulate fishery activities inside the MPA of the RLPL. Thus, our study results were used to propose an adaptive strategy to management small-scale fisheries within MPAs in balance with natural resources conservation. The key role of the MPA-RLPL in conservation ecology was revealed through a comparative analysis with larger areas distributed in the jurisdictional waters of Uruguay or under binational management with Argentina.