Variations of planktonic chlorophyll-a in relation to environmental factors in a Mediterranean Coastal System (Iskenderun Bay, Northeastern Mediterranean Sea)

Chlorophyll-a is one of the most widely used parameters to estimate trophic state of an aquatic environment. The purpose of this study was to investigate the changes in the planktonic chlorophyll-a concentrations in relation to environmental parameters in the east part of Iskenderun Bay (Northeastern Mediterranean Sea). Monthly measurements of chlorophyll-a and inorganic nutrients were done on two transects at 6 stations across the Bay. In addition, variations in temperature, salinity and some meteorological factors were also investigated, their correlation with chlorophyll-a were analyzed. The highest chlorophyll-a concentration (3.8 μg L-1) was found on coastal transect nearer to the bay. The first peak in chlorophyll-a occurred in May, a second smaller peak was recorded in September. The correlation of chlorophyll-a was significantly positive for Silicate-Si and Nitrate+nitrite-N but not important for Phosphate-P. No dramatic increase in chlorophyll-a levels was encountered in the area during the study period. It was concluded that, due to the hydrodynamic structure of the area, the land-based effects influence chlorophyll-a dynamics

Contribution and acclimatization of the swarming tropical copepod Dioithona oculata (Farran, 1913) in a mediterranean coastal ecosystem

In this study, tropical oithonid copepod Dioithona oculata was recorded for the first time in the Mediterranean Sea. This species is distinguished easily by its large ocular lenses and by the number of setae on the endopod of the maxillule. The study was conducted seasonally in the coastal area of İskenderun Bay between April 2013 and December 2016. D. oculata was first observed in October 2013 in the study area (Station 4; 3.1 ind. m–3); after this period, this species became an important contributor to zooplankton assemblages in October with the highest level seen in 2016 (Station 4, 834.5 ind. m–3). The proportion of this species in the copepod community varied from 0.14% (2014) to 29.4% (2016), and the highest proportions, observed in October 2016, were at Stations 3 and 4 (51.1% and 65.3%, respectively). Females dominated the D. oculata population and the ratio of female to male was 5.6 ± 7 on average. Copepodit stages were also observed in the population. Altogether, these data indicate that the D. oculata population increased year after year. In addition, the presence of copepodits in the population suggests that this species was established and successfully acclimatized to the conditions, becoming an important component of the zooplankton community in the İskenderun Bay ecosystem. © TÜBİTAK

A new species of Cymbasoma (copepoda, monstrilloida) from the northern coast of Turkey (Black Sea) with comments on the C. longispinosum species-group

Cymbasoma sinopense sp. nov. is described from an adult female collected off the Sinop coast, in the southern Black Sea, Turkey. This is the first species of this genus recorded from the Black Sea coast of Turkey. The new species is a member of the widespread Cymbasoma longispinosum species-group, and it closely resembles C. chelemense Suárez-Morales & Escamilla, 1997 from the Yucatan Peninsula and C. californiense Suárez-Morales & Palomares-García, 1999 from the Gulf of California. This species can be distinguished by a combination of subtle characters, including the body proportions, the structure and armature of the fifth legs, the ornamentation of the genital somite, and the relative length of the ovigerous spines. A previous report of C. longispinosum from the northern Black Sea probably represented a misidentified record of C. sinopense sp. nov. The Mediterranean reports refer to a species that is different from the one of the Black Sea. Comparative comments and data including the main taxonomic characters of members of the Cymbasoma longispinosum species-group are presented. Overall, it is confirmed that records of this species from different geographic areas should be revised carefully because they could represent undescribed species. A key for the identification of the females of the currently known species assigned to the Cymbasoma longispinosum species-group is included. © 2014 Koninklijke Brill NV, Leiden

First record of Ferosagitta galerita (Dallot, 1971) [Chaetognatha] in the Mediterranean Sea

The first record of Ferosagitta galerita in the Mediterranean Chaetognatha fauna is reported. The morphological and ecological features of this species, which was hitherto only known to live near Madagascar in the Indian Ocean, are given in detail. With this new finding, the number of chaetognath species to be known in the Mediterranean Sea is increased. © The Author 2007. Published by Oxford University Press. All rights reserved

Mesozooplankton in the open Black Sea: Regional and seasonal characteristics

Coordinated cruises conducted in the Black Sea offshore waters in spring and autumn 2008, within the framework of European project SESAME, allowed the obtainment of a quasi-synoptic picture of the mesozooplankton standing stock and community composition. A clear spatial difference in total abundance was observed in spring with higher values over the slope than over the deep basin, due to the development of the fast boundary current. In autumn, standing stock was lower than in spring weakening of the boundary current and extensive eddy formation caused small-scale variability in mesozooplankton distribution and intensification of the exchange between the different parts of the sea. In both seasons, copepods comprised the bulk (62-95%) of mesozooplankton biomass. Community composition variability was tested for the first time using data obtained from the entire basin; the application of neural network analysis (Self-organizing Maps) revealed a rather homogenous picture of community composition. The development of cladocerans in autumn resulted in the differentiation of the slope areas from the deep basin. Mass development of the heterotrophic dinoflagellate Noctiluca scintillans was observed in the western and north-western areas in autumn. No change in standing stock values and community composition seem to have occurred since 2000 in the north-eastern region. © 2013 Elsevier B.V

Copepod communities, production and grazing in the Turkish Straits System and the adjacent northern Aegean Sea during spring

The Mediterranean and the Black Seas are connected through Bosphorus, Marmara Sea and Dardanelles (Turkish Straits System, TSS). In this study, we examined the spatial distribution of copepods and investigate their production and grazing. The aim was to understand the transfer of phytoplankton/microzooplankton production up the food chain in TSS and Aegean Sea during spring. The phytoplankton and microzooplankton biomass and production showed a clear decreasing trend from Bosphorus to the Aegean Sea, whereas copepod biomass did not reveal any distinct trend and only the number of copepod species increased from Bosphorus to the Aegean Sea. Production of copepods and egg production showed similar trends except for the Bosphorus, where production of copepods was very low due to the low copepod biomass in this area. In all areas, the copepod carbon demand was largely met by phytoplankton and microzooplankton production. However, only a low amount of primary production was consumed by copepods and production appeared to flow mostly through other pathways (microbial loop) and/or sediment on the bottom. The results of this study confirm the hypothesis that there is a substantial differentiation within pelagic food web structure and carbon flow from Bosphorus to the Aegean Sea

Regional and seasonal characteristics of epipelagic mesozooplankton in the Mediterranean Sea based on an artificial neural network analysis

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