An INTERdisciplinary view on Argentine CANYON systems using isopod crustaceans of the Mar del Plata canyon as surrogate

DOTI, B. L.; SCHWENK, T.; KASTEN, S.; BRIX, S.

Simposio; V INCISE Symposium (International Network for Submarine Canyon Investigation and Scientific Exchange); 2021

University of Gibraltar

While the Argentinian shelf has been studied in more detail, the benthic communities of the submarine canyons placed along the Argentine Continental Margin remain almost unexplored. More recently, there were three expeditions (Talud Continental I?III; RV Puerto Deseado) to the Mar del Plata submarine canyon. As a result of these expeditions several new species and new records on different phyla were reported. In addition, we carried out a pilot study with data and samples collected during cruise SO260 with RV Sonne in 2018 around the Mar del Plata Canyon. Bathymetric and PARASOUND data of 10 stations were analyzed and compared with grain size data from surface samples revealing that the station locations clustered into four types of morpho-sedimentary environments, namely, ?Drift Deposit?, ?Terraces, Channels, Depressions?, ?Canyon Terrace? and ?CWC (Cold Water Corals)?. Based on these morpho-sedimentary environments, a preliminary biological dataset based on boxcorer samples shows a correlation of the benthic faunal assemblages with potential CWC reefs in case of peracarid crustaceans. In addition to the samples taken during the cruise SO260 in 2018, we have several samples taken on board the Argentinean RV Puerto Deseado. These stations will be used as comparison to evaluate the changes in the community structure with the bathymetric range from the slope and along the canyon (from 250 m to 3282 m depth). This analysis is aimed to set the baseline of the planned INTERCANYON project (INTERdisciplinary view on Argentine CANYON systems). As starting point, we aim to study the changes of benthic communities along the Mar Del Plata canyon, focusing mainly on isopods (Crustacea: Peracarida) as surrogate group. In particular, we propose 1) to evaluate differences in the benthic isopod communities along the bathymetric range of the canyon; 2) to study the isopod assemblages in the different morpho-sedimentary environments of the canyon; and 3) to evaluate the isopod diversity inside and outside the canyon.