engleski

Newly recorded zooplankton species in the Adriatic Sea from 1993-2011: indicators of the hydroclimatic changes in the Eastern Mediterranean

Analysis of plankton samples from 1993 to 2011 in the South Adriatic putlined important changes in species composition and abundance in the non-crustacean zooplankton community. Ten species were recorded for the first time in the Adriatic: Desmopterus papilio, heteropod Protatlanta mediterranea, calycophorae Muggiaea atlantica and Lensia subtiloides, hydromedusa Niobia dendrotentaculata, thaliacea Thalia orientalis, ctenophore Charistephane fugiens, polychaeta Pontodora pelagica, Phalocrophorus pictus, chaetognatha Sagitta galerita. Three species reappeared after some period of absence: polychaeta Pelagobia longicirrata, heteropod Oxygyrus keraudrenii and thaliacea Brooksia rostrata. Some of this newly recorded species have replaced its formerly dominant autochthonous congener. The presence of Atlantic and western Mediterranean species in the Adriatic Sea is concomitant with the anticyclonic circulation in the north Ionian gyre (NIG) and thus with advection of modified Atlantic water into the Adriatic. On the other hand, records of Lessepsian organisms originating from tropical and/or temperate areas coincide with the cyclonic NIG that advects eastern Mediterranean waters into the Adriatic, blocking the MAW intrusion. Therefore, the arrival of alochthonous species into Adriatic was caused by circulation shifts which in turn depend on larger scale processes. This is a likely scenario for future colonisations in which alien species arrive due to climate-induced disruption of circulation barriers.

alien species; zooplankton; Adriatic sea

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