TY - JOUR T1 - Short term changes in zooplankton community during the summer-autumn transition in the open NW Mediterranean Sea: species composition, abundance and diversity A1 - Raybaud,V. A1 - Nival,P. A1 - Mousseau,L. A1 - Gubanova,A. A1 - Altukhov,D. A1 - Khvorov,S. A1 - Ibanez,F. A1 - Andersen,V. AD - Univ Paris 06, UPMC, UMR 7093, Lab Oceanog Villefranche, F-06230 Villefranche Sur Mer, France. AD - CNRS, UMR 7093, LOV, F-06230 Villefranche Sur Mer, France. AD - IBSS, Plankton Dept, UA-99011 Sevastopol, Crimea, Ukraine. UR - https://archimer.ifremer.fr/doc/00208/31975/ DO - 10.5194/bg-5-1765-2008 KW - ligurian sea KW - wind events KW - phytoplankton community KW - vertical distributions KW - seasonal variations KW - english channel KW - spring bloom KW - oregon coast KW - variability KW - copepods N2 - Short term changes in zooplankton community were investigated at a fixed station in offshore waters of the Ligurian Sea (DYNAPROC 2 cruise, September-October 2004). Mesozooplankton were sampled with vertical WPII hauls (200 mu m mesh-size) and large mesozooplankton, macrozooplankton and micronekton with a BIONESS multinet sampler (500 mu m mesh-size). Temporal variations of total biomass, species composition and abundance of major taxa were studied. Intrusions of low salinity water masses were observed two times during the cruise. The first one, which was the most intense, was associated with changes in zooplankton community composition. Among copepods, the abundance of Calocalanus, Euchaeta, Heterorhabdus, Mesocalanus, Nannocalanus, Neocalanus, Pleuromamma and also calanoid copepodites increased markedly. Among non-copepod taxa, only small ostracods abundance increased. After this low salinity event, abundance of all taxa nearly returned to their initial values. The influence of salinity on each zooplankton taxon was confirmed by a statistical analysis (Perry's method). The Shannon diversity index, Pielou evenness and species richness were used to describe temporal variations of large copepod (> 500 mu m) diversity. The Shannon index and Pielou evenness decreased at the beginning of the low salinity water intrusions, but not species richness. We suggest that low salinity water masses contained its own zooplankton community and passed through the sampling area, thus causing a replacement of the zooplankton population. Y1 - 2008 PB - Copernicus Publications JF - Biogeosciences SN - 1726-4170 VL - 5 IS - 6 SP - 1765 EP - 1782 ID - 31975 ER -