Uso de BRUVS para describir el ensamble de peces y su estacionalidad en dos caletas marinas poco profundas dentro de áreas protegidas de la Patagonia, Argentina

Gastón Trobbiani,Nelson Bovcon,Agustin M De Wysiecki,Alejo J Irigoyen

doi:10.25260/ea.21.31.1.0.1152

Abstract

Baited Remote Underwater Video Stations (BRUVS) complemented with fishing methods were used to describe the fish assemblage and its seasonal pattern in two marine inlets from Patagonia. The combined results for BRUVS and fishing sessions identified 13 fish species. Our results agree with the biogeographic schemes proposed for the southern Southwest Atlantic. The fish species belonging to the Argentine Biogeographic Province presented a seasonal pattern with a peak of maximum abundance (Notorynchus cepedianus and Galeorhinus galeus) or were recorded during warm months only (Mustelus schmitti, Myliobatis goodei, and M. ridens), coinciding with the general latitudinal pattern expected for fish species richness. The use of BRUVS in this study allowed for the assessment of different fish species and wide range of sizes, from large sharks (N. cepedianus) to small cryptic species (Patagonotothem sp.). However, three of 13 species were only recorded by fishing methods, like it was the case for M. ridens. The record of M. ridens is the first in Patagonian waters, extending its distribution for c. 180 km south of the previously known southern limit. This study contributes to filling large data gaps along the Southwest Atlantic regarding the description and understanding of the temporal dynamics of fish assemblages in particular environments within protected areas.

Highlights

Using Baited Remote Underwater Video Stations (BRUVS) to describe the fish assemblage and its seasonality in two shallow marine inlets within protected areas of Patagonia, Argentina
The fish species belonging to the Argentine Biogeographic Province presented a seasonal pa ern with a peak of maximum abundance (Notorynchus cepedianus and Galeorhinus galeus) or were recorded during warm months only (Mustelus schmi i, Myliobatis goodei, and M. ridens), coinciding with the general latitudinal pa ern expected for fish species richness
The Magellanic Province includes the Patagonian shelf from Cabo de Hornos (55° S) to Península de Valdés (43° S) and it follows a northward path along the edge of the continental shelf (Balech and Ehrlich 2008)

Summary

Study site

The study sites are two inlets within MPAs of northern and central Patagonia, namely Caleta Valdés (~42.5° S) and Caleta Malaspina (~45.1° S), which have a complete marine regime (Figure 1a-b). Caleta Malaspina (CM) is located at the northern extreme of San Jorge gulf and it is a part of the Interjurisdictional Marine Coastal Park Patagonia Austral (Figure 1b) This MPA is a protected area of 750. A priority has been placed to protect birds and marine mammals, it is a spawning area for fish and crustacean species (Yorio 2009) which have been little studied in relation to other groups of animals. Both inlets are characterized by a narrow and long water intrusion bounded either by a 35 km-long gravel bank (CV, Figure 1a) or by 10 km-long rocky and gravel shores (CM, Figure 1b). Water surface temperature fluctuates seasonally between a mean value of 8.6 °C in September and 17.9 °C in March in CM, and between 9.6 °C and 17.9 °C in the same months in CV (average monthly Sea Surface Temperature for the study period 2015-2019, Aqua MODIS; URL: https://tinyurl.com/ybq3axld)

Sampling design

Fishing sessions

Data analysis

Findings

RAR WDF