Zooplankton composition and distribution across coastal and offshore waters off Albania (Southern Adriatic) in late spring

We present for the first time composition, numerical abundance and vertical structure ofmicro-and mesozooplankton in the Albanian coastal and open sea region. Zooplankton was sampled at six stations on the 75-km long continental shelf slope transect in May 2009. The most numerous microzooplankton were copepod nauplii (maximum: 39 ind. L super(-1)), followed by calonoid and cyclopoid copepodites (maxima: 5 and 4 ind. L super(-1), respectively). The most abundant of fourteen tintinnid species was Tintinnopsis radix, found in the surface to 50 m layer. The species composition of the coastal and open sea mesozooplankton was similar to that previously reported for the south Adriatic Sea. The copepod Oithona similis was the dominant species at all stations, followed by Oithona plumifera, Acartia clausi, Paracalanus parvus, Oithona nana and cyclopoida-oncaeids at the shallower coastal stations, and Clausocalanus pergens, Oithona plumifera and Oithona nana offshore. Mesozooplankton diversity rose considerably from the coast to the open sea. Mesozooplankton abundance exhibited the opposite trend, with the maximum (2286 ind. m super(-3)) noted at the shallowest station. Findings of typically open sea tintinnid and copepod species at the coastal station indicate the high influence of currents from the open sea area during our investigation. Our results suggest the low influence of fresh water on zooplankton population densities, even at the shallow stations where penetration of fresh water in the surface layers was notable.Original Abstract: Po prvi put su prikazani sastav, abundancija i vertikalna struktura mikro- i mezozooplanktona u albanskim obalnim i otvorenim vodama. Istrazivanje je obavljeno na sest postaja duz 75 km dugom transektu od selfa do kontinentskog slaza. Najbrojniji predstavnici mikrozooplanktona su bili kopepodni naupliji (maksimum: 39 ind. L super(-1)), iza kojih su slijedili kalanoidni i ciklopoidni kopepoditi. Od 14 zabiljezenih vrsta tintinida, najbrojnija je bila vrsta Tintinnopsis radix, nadena od povrsine do 50 m dubine. Sastav zajednice mezozooplanktona obalnog i otvorenog mora u skladu je s prijasnjim istrazivanjima juznog Jadrana. Kopepod Oithona similis bila je dominantna vrsta na svim istrazivanim postajama. Na plicim postajama slijede je vrste Oithona plumifera, Acartia clausi, Paracalanus parvus, Oithona nana i cyclopoida-oncaeids, a u otvorenim vodama vrste Clau-socalanus pergens, Oithona plumifera i Oithona nana. Bioraznolikost mezo