Spatial and temporal distribution of mesozooplankton in the coastal waters of Cyprus (Eastern Mediterranean)

Abstract

This study provides elements on the spatial and temporal mesozooplankton variability during a three-year study, encompassing vertical hauls from 50 m deep to the surface from four coastal locations of Cyprus. The total mesozooplankton abundance fluctuated between 190.4 and 882.5 individuals m-3. A total of 90 holoplanktonic and meroplanktonic taxa were recorded. Copepods dominated in the community and accounted for 71.7% of the total mesozooplankton, followed by appendicularians, molluscs, cladocerans, and siphonophores, which contributed 8.04%, 5.48%, 4.60%, and 3.31%, respectively. There were no statistically significant differences among the four sampling sites for any of the mesozooplanktonic taxa, though seasonal and interannual differences were recorded for several of them. The community composition reinforced the evidence for a higher resemblance of the Cyprus mesozooplankton to the offshore communities of the northern and central Levantine Sea and those around Rhodes Island, instead of the northeastern Mediterranean coastal areas. Comparisons of the seasonal abundance variation of the mesozooplankton taxa with other coastal areas of the Levantine Sea are provided. Considering the seasonality of the mesozooplankton, there was a separation of the taxa into distinct groups representing the summer, the winter-spring, and the autumn periods. The temperature was the most important variable that shaped the formation of the distinct seasonal groups of taxa, while chlorophyll-α, dissolved oxygen, and salinity contributed to a lesser extent. Chlorophyll-α concentrations verified the oligotrophic character of the area and seem to be unaffected by inland inputs. The mesozooplankton community showed a spatial consistency, probably as the result of the open sea influence, and seems to be regulated mainly by the properties of the central Levantine pelagic waters and less by terrestrial inputs of inland waters.

Annual cycle of mesozooplankton at the coastal waters of Cyprus (Eastern Levantine basin)

“…Moreover, the fact that VAS1 and VAS2 are shallower stations in comparison to AKR and PYR, possibly contributed to the increase of population of I. clavipes , as this species seems to prefer swallower waters. The bloom event of Isias clavipes it seems to be the reason for the higher value of abundance that was ever reported in the coastal of Cyprus, compared to previous studies ( Hannides et al., 2015b ; Vasilopoulou et al., 2022 ). In addition to that event, VAS1 and VAS2 generally presented higher MZ abundance in the layer 0–50 m, compared to AKR and PYR ( Fig.…”

“…The previous attempts investigating MZ in the coastal waters of Cyprus ( Hannides et al., 2015b ; Vasilopoulou et al., 2022 ), were carried out mainly with seasonal sampling, but with gaps among seasons and stations. The sampling locations, of the current study, which were selected based on the differences in temperature (Akrotiri and Kato Pyrgos) and anthropogenic pressures gradient (Vasiliko) are geographically in different locations from the sampling stations of the previous studies.…”

“…Moreover, the monthly sampling of MZ in our work was carried out using a WP2 closing net, by conducting two vertical tows, 0–50 m and 50–100 m, in AKR and PYR, investigating the vertical distribution of MZ, while Hannides et al. (2015b) carried out vertical tows with an average tow depth ~ 100 m and Vasilopoulou et al. (2022) carried out only one vertical tow (0–50 m), overall.…”

“…Sampling with finer mesh nets than the standard 200 μm, has revealed that biomass and abundance can increase by 2- to 20-fold when the smaller metazooplankters (∼50–200 μm) are considered ( Zervoudaki et al., 2006 ; Zervoudaki et al., 2020 ). Nevertheless, the use of 200—μm mesh nets, which is commonly used in the majority of zooplankton studies in the Mediterranean allows the comparison among other studies conducted in the area ( Hannides et al., 2015b ; Terbiyik-Kurt and Polat, 2015 ; Vasilopoulou et al., 2022 ;) as well as with other geographical regions, e.g. Aegean ( Isari et al., 2006 ) and Western Mediterranean ( Mazzocchi et al., 2011 ).…”

“…Several studies on the seasonal variability of zooplankton have been conducted in different coastal regions of the Mediterranean Sea ( Calbet et al., 2001 ; Mazzocchi et al., 2011 ; Yebra et al., 2022 ; Zervoudaki et al., 2020 ). However, little information and few data are available regarding zooplankton in Cyprus ( Siokou-Frangou et al., 1997 ; Hannides et al., 2015a ; Hannides et al., 2015b ; Samuel-Rhoads et al., 2016 ; Vasilopoulou et al., 2022 ). Despite the available information on zooplankton in Cyprus open waters, there is still a lack of information regarding monthly variability of mesozooplankton communities and detailed species composition in the coastal waters.…”