Net-zooplankton abundance and biomass from Annaba Bay (SW Mediterranean Sea) under estuarine influences

Abstract

Zooplankton samples were collected in Annaba Bay (Algeria) from January 2009-March 2011 at three coastal sites differently affected by estuarine plumes and external currents. Aim of this survey was to analyze zooplankton composition, abundance and biomass and compare the results with previous studies to reveal possible populations and environmental changes. The mean zooplankton abundance varied between 1,200-6,000 ind. m-3 and biomass 6.70-25.70 mg DW m-3, according to the site. Copepods constituted the main fraction of zooplankton community, and Oithona similis and Paracalanus indicus successively dominated during autumn-winter and spring-summer. The dinoflagellate Noctiluca scintillans was one of the major zooplankton components, and developed high numbers during February-April, becoming common in neritic and coastal regions. The singularity of the zooplankton from Annaba Bay is the prevalence of P. indicus throughout the entire bay and the decrease in Acartia discaudata and A. clausi (with respect to previous years), possibly replaced by A. negligens. Additionally, Oithona nana abundance markedly decreased with the large development of O. similis. Annaba Bay also differs from other similar Mediterranean coastal areas by the large development of Centropages ponticus populations during the warm period. Among the identified copepod species, the alien species Pseudodiaptomus australiensis and P. arabicus are reported for the first time in the Mediterranean Sea. The occurrence of copepodid V stages of P. australiensis suggests that this species survives and reproduces in Annaba Bay, but so far without developing an abundant population.

Marine Bryozoa of Greece: an annotated checklist

“…As this is the first attempt to compile a checklist of bryozoan diversity of the Greek seas, we performed an exhaustive literature review of bryozoan records. All taxa were cross-checked for synonymies and dubious records against the World List of Bryozoa (recent and fossil), the World Register of Marine Species (Bock and Gordon 2016, WoRMS Editorial Board 2016), and the recent update of the Mediterranean bryozoan diversity by Rosso and Di Martino (2016). Taxa identified as cf., as well as those left in open nomenclature, and fossil records were not included in the list.…”

“…Two new species, Stephanotheca watersi Reverter-Gil, Souto & Fernandez-Pulpeiro, 2012 and Schizomavella adriatica Reverter-Gil, Souto, Novosel & Tilbrook, 2016 have been erected to allocate some records from the western Basin and the Adriatic, respectively. Nevertheless, records and material from the Aegean were not considered and hence they are provisionally still reported as S. rudis (see also Rosso and Di Martino 2016). …”

“…Harmelin 1969, Hayward 1974, Morri et al 1999; the status of these records needs to be checked (see Rosso and Di Martino 2016​).…”

“…The Mediterranean bryozoan fauna represents about 9.6% of the known global diversity of Bryozoa (Rosso and Di Martino 2016). However, current knowledge on the bryozoan fauna of this basin is highly biased due to differences in research effort for different taxa, marine areas and habitat types.…”

Copepod community along the Mediterranean coast of Morocco (Southwestern Alboran Sea) during spring

“…An overview of the plankton studies conducted during the last 25 years in the epipelagic offshore waters of the Mediterranean Sea, revealed a considerable spatial variability (SiokouFrangou et al, 2010). However, zooplankton studies inthe Southern Mediterranean are strongly limited (Riandey et al, 2005;Khelifi-Touhami et al, 2007;Zakaria, 2006;Ounissi et al, 2016) when compared to those in the Northern Mediterranean (e.g. Alcaraz et al, 2007;Fernandez de Puelles et al, 2007;Raybaud et al, 2008;García-Comas et al, 2011;Mazzocchi et al, 2011).…”