2002 vs. 2012: A re-assessment of the marine bioinvasions in the Southwestern Atlantic (SWA, 34º- 55ºS) coast

SCHWINDT E; JAMES T. CARLTON; ORENSANZ JM; F SCARABINO,; BORTOLUS A

Congreso; 8th International Conference on Marine Bioinvasions; 2013

UBC Vancouver

We conducted a re-assessment of the marine bioinvasions of Argentina and Uruguay combining (1) updated taxonomic and systematic works with (2) an exhaustive review of the historical literature and museum records, with the goal of performing a detailed spatio-temporal analysis. The number of exotic species recorded in 2012 was three times higher (n=97) than previously (2002) known (n=31); 43% of the new records are from the literature and 15% are new arrivals during the last ten years. Crustaceans comprised 24.4% of the exotics species followed by macroalgae with 17.5%. Among the exotics, 75% of the species originated from the northern hemisphere, with only 6% originating from the southern hemisphere. The rate of discovery increased over time but the steepest rate was between 1960 and 1970. Ship fouling was the most likely vector (38%) followed by ship fouling and ballast water combined (i.e. multiple vectors, 27.8%). Cryptogenic species followed a similar trend as exotics: 43 (2002) to 65 (2012) species, with nearly half found in the literature. Crustaceans were also the dominant taxa (21.5%); hydroids, polychaetes and macroalgae followed in importance (15% of the records each). The rate of discovery showed similar patterns of exotics species as well as the likely vector, with 46% for multiple vectors and 41% for ship fouling alone. Our results bring new light to the understanding of marine bioinvasions at a regional scale pointing out the relevance of taxonomic work, and also contribute to improve the effectiveness of regulations and management strategies across regions.