The analysis of euphausiid larvae collected during summer 2011 in the Weddell Scotia Confluence región, in 2012 on the WAP and Scotia Sea and 2014 on the South Orkneys Platform show a strong decrease in the abundance of Euphausia superba larvae and an increase in Thysanoessa macrura in 2011 and 2012 and a strong increase in the abundance of E. superba in 2014. Oceanographic conditions didn’t show any significant variations respect historical information. The analysis was conducted using cluster analysis finding that the associations of the different larvae and especies correspond to the available information. The densities observed during the cruises were compared with densities obtained in 1981 and 1995 calculating expected values at a fixed grid of points. The significance of the differences was established using a binomial test on their signs.
Dr Emilce Florencia Rombolá (Argentina)
Dr Enrique Marschoff (Argentina)