Zahit Uysal

Checklist of copepods (Calanoida and Podoplea) from the northern Levantine basin shelf waters

This paper is based on the qualitative and quantitative description of planktonic materials collected from the northern Levantine basin shelf waters during the period 1998–1999. Analysis of a total of 75 zooplankton samples collected along the Turkish Mediterranean coast has shown the presence of approximately 200 copepod species. Among these, 76 species are recognised for the first time in this region including four new species. At present, the total list of copepod species from the Levantine basin numbers 233, with several Indo–Pacific species included. The copepod species inhabiting the region are interesting not only because of faunistic properties, but also due to their distribution, which is related to the existing current regime.

Pigments, size and distribution of Synechococcus spp. in the Black Sea

Pigments, size and distribution of Phycoerythrin-containing unicellular cyanobacteria Synechococcus spp. within the euphotic zone were studied for the first time in April–May 1994 in the western and southwestern Black Sea by epifluorescence microscopy and flow-cytometry. Synechococcus was present in varying quantities at every station and depth studied. Surface spatial distribution of Synechococcus revealed that cells were much more abundant in offshore waters than near coastal regions under the direct influence of the Danube river. Minimum and maximum cell concentrations ranged between 9×102 and 1.45×105 cells/ml at the surface, between 2×103 and 1.23×105 cells/ml at the chlorophyll sub-maximum layer, and between 1.3×102 and 3.5×102 at the nitrite maximum layer. Cells at the chlorophyll sub-maximum layer (based on in-situ fluorometer readings) fluoresce brighter and longer than the ones at the surface and lower depths. Spectral properties of chromophore pigment types of total 64 clonal isolates from different depths down to the lower layer of the euphotic zone (∼60 m) in the southern Black Sea coast revealed that all have type 2 phycoerythrobilin in common, lacking in phycourobilin. In vivo fluorescence emission maxima for the phycoerythrobilin were about the same (∼578 nm) for all isolates. All isolates examined showed in vivo absorption maxima at between 435 and 442 nm and at about 681 nm due to chlorophyll-a. Based on the flow cytometer mean forward light scatter data for size distribution, it could be concluded that cells at the surface mixed layer (0–10 m) were larger in cell size than the cells at lower depths (20–60 m).

On the formation of net phytoplankton patches in the southern Black Sea during the spring

Species composition, community structure and spatial distribution of net phytoplankton in the southern Black Sea have been studied. In the fraction over 55 μm, diatoms were found to be predominant in cell abundance and followed by dinoflagellates. Net phytoplankters were found to be more abundant in the southwestern sector, especially near the Bosporus and near Sakarya River mouth. MDS (Multi-Dimensional Scaling) analysis has projected four distinct patches along the coast, two of which appear to occupy smaller regions compared to the main western and eastern patches which have lower species numbers and diversity. The diatom species Pseudo-nitzschia seriata and Cerataulina pelagica and the dinoflagellates Noctiluca scintillans and Scrippsiella trochoidea dominate the west, while diatom species Synedra acus and Asterionella formosa together with Microspora sp. and Ankistrodesmus falcatus from chlorophyceae dominate the east.

Species composition, abundance and biomass of Copepoda in plankton of the northern Levantine Basin (eastern Mediterranean)

Changes in species composition, abundance and biomass of copepods were monitored weekly over the year 1998 in shelf waters of the northern Levantine Basin. A total of 192 copepod species belonging to 61 genera were identified during the course of this study. Thirty-six species are reported for the first time from the region, including three new species. Copepod abundance ranged from 215 individuals m−3 in early March to 2220 individuals m−3 in late March, whereas the biomass ranged from 4 mg m−3 in mid-January to 22 mg m−3 in mid-February. The copepod fauna was found to be most species-rich on 4 November (Margalef’s Index d = 7 . 4 ) and least on 10 March ( d = 3 . 3 ). The index was found low during spring and autumn with lowest levels obtained during the stratification period from September to October. The diversity was found to be highest on 18 February (Shannon-Wiener Index H ′ = 2 . 9 ) and lowest on 31 March ( H ′ = 1 . 6 ). Higher index values were characteristic of the winter period. A proportional representation of the species among their populations was well established during February whereas the best situation was met on 3 March and the most unbalanced situation at the end of March. Multivariate analyses have shown the formation of distinct seasonal communities of copepod species throughout the year. The observed seasonality in community structure is suggested to be a result of wide range changes in temperature throughout the year. The dominant species observed during late winter and spring were Oithona nana, Oithona sp., Oncaea media, Oncaea sp., Calocalanus elegans, Euterpina acutifrons and Oncaea zernovi, respectively. Calocalanus sp., C. elegans, Triconia dentipes, Oncaea sp., Oithona nana, Clausocalanus furcatus, and Temora stylifera were dominant during summer, whereas Oncaea sp., Calocalanus sp., Oithona nana, Clausocalanus paululus, C. furcatus, Parvocalanus sp., and Calocalanus elegans dominated the autumn and early winter populations. Sharing similar species with the Indo-Pacific region gives the copepod fauna of the Levantine Basin, at least in part, a subtropical affinity.

Composition and Abundance of Zooplankton of the Eastern Mediterranean Sea

Results of investigations on the composition and quantitative distribution of zooplankton of the eastern Mediterranean Sea were reviewed for the period 1950-1980. The studies reviewed comprise more than 250 stations (with about 2000 samples) mainly from the expeditions carried out by the Institute of Biology of the Southern Seas (IBSS), attached to the National Academy of Science of the Ukraine. Many of these stations are located in poorly studied deep-water regions. For comparison purposes data from the literature on the coastal regions were also used.

Abundance and biomass of picoplanktonic Synechococcus (Cyanobacteria) in a coastal ecosystem of the northeastern Mediterranean, the Bay of İskenderun

Abstract Changes in abundance and biomass of Synechococcus were studied during five cruises carried out between November 2004 and September 2005 in the İskenderun Bay, northeastern Mediterranean. In addition, spatial and temporal variations in physico-chemical factors and Chl a were measured. Abundance ranged from 0.2×104 to 23.09×104 cells ml−1, whereas the biomass ranged from 0.19 1 to 23.01 µgC l−1 in the bay. Synechococcus was found most numerous during September 2005 in the shallower part of the bay while the population was observed least during November 2004 and January 2005. The contribution of <3 µm size fraction to total Chl a ranged between 48% and 74%, being low during the cold period and higher during the warm period. The observed spatial and temporal fluctuations in abundance seemed to be closely related to environmental conditions in the area. Small-sized phytoplankton dominated the bulk of biomass, at least for the summer period.

New species of the genus Scaphocalanus (Calanoida: Scolecithricidae) from the Iskenderun Bay – northeastern Levantine Basin

A new calanoid copepod species Scaphocalanus emine n. sp. is described for the first time from the Iskenderun Bay, northeastern Levantine Basin. S. emine is similar to S. affinis (Sars, 1905) having both identical orientation of the posterolateral corners of the cephalothorax and a median crest on the forehead. The new species is also similar in some features to S. affinis in the structure of Re1P1- lacking the outer marginal spine and by the presence of the rounded apex on the distal internal margin. It differs from S. affinis as the median crest on the forehead is smaller and due to the presence of a rudimentary endopod furnished with an apical spine on the P5. Originality in construction of the P1 and P5 distinguish the new species from other Scaphocalanus species.

VARIABILITY IN PHYTOPLANKTON PIGMENT COMPOSITION IN MERSIN BAY

Phytoplankton pigment composition and associated biochemical (chlorophyll a , nitrate+nitrite, ammonia, phosphate, silicate ) and physical (temperature, salinity) parameters were studied seasonally in the river-fed eutrophic coastal and oligotrophic offshore waters of the Mersin Bay located on NE Mediterranean. Total chlorophyll a concentrations varied seasonally between 0.023 - 7.73 µg/l in the river fed coastal zone (salinity: 36.54-39.68), exhibiting less seasonality in the offshore station (0.01 – 0.91 µg/l). S even different phytoplankton taxa (namely d iatoms, cyanobacteria, prymnesiophytes, dinoflagellates, chlorophytes, chrysophytes, prochlorophytes), determined by H igh Performance Liquid Chromatography (HPLC), were consistently present in the coastal waters during 2008-2011. The predominant diatom and coccolithophorid taxa in the river-fed coastal waters were replaced by prokaryotic picoplankters (cyanobacteria & prochlorophytes) and prymnesiophytes in the offshore. Contribution of prokaryotic picoplankton and eukaryotic nanoflagellates to total chlorophyll (% 23 to 47 and % 28 to 43, respectively) increased by about 50% from the coastal to the offshore station. Contribution of large cells to total chlorophyll decreased from 49% to 10% towards offshore. Prochlorophytes were observed as the dominant group in relatively colder and darker deep waters.

MONTHLY CHANGES IN THE COMPOSITION AND ABUNDANCE OF MEROPLANKTON AND PELAGIC POLYCHAETES OF THE CILICIAN BASIN SHELF WATERS (EASTERN MEDITERRANEAN)

Taxonomic composition of the meroplankton and the pelagic polychaetes of the Cilician basin shelf waters was investigated for the first time. Analysis of monthly net samples shows that the meroplankton and the pelagic polychaetes of the region are represented under 5 phyla, 10 classes, and 34 families. Pelagic nectochaete larvae of the family Spionidae (Polychaeta) and zoeas of family Grapsidae (Decapoda) were the dominating groups throughout the year. Typical stenohaline taxa formed by classes of Enteropneusta, Ophiuroidea, Asteroidea, Echinoidea, and Holothuroidea were also observed. The predominance of the decapod larvae was a distinguishing feature of the winter period. Diversity was highest during the spring (Margalef’s Index d = 4.3, 5.4, and 5.6 for March, April, and May, respectively) and lowest during August (d = 1.9) and November (d = 2.3). Results of multivariate analysis (Multi-Dimensional Scaling) revealed a distinct summer population that varied greatly from the rest of the periods. Temperat...

Kuzeydoğu Akdeniz’de Kıyısal ve Açık sularda Fitoplankton Dinamikleri

K uz eydogu Akdeniz’de acik ve nehir etkisinde kalan kiyisal sulari temsilen belirlenen iki istasyonda fitoplankton dinamiklerini incelemek amaciyla Mayis 2010 – Ekim 2011 tarihleri arasinda aylik orneklemeler yapilmistir. Fitoplankton pigment orneklemelerinin yani sira sicaklik ve tuzluluk verileri de toplanmistir. Fitoplankton biyokutle gostergesi olan klorofil- a ve yedi farkli fitoplankton grubunu (siyanobakteriler, proklorofitler, krizofitler, primnesiyofitler, klorofitler, diatomlar ve dinoflagellatlar) temsil eden belirtec pigmentler Yuksek Performansli Sivi Kromatografi (HPLC) teknigi ile olculmustur. Ornekleme donemi boyunca yuzey klorofil-a konsantrasyonlari kiyi icin <0.01 – 6.305 µg/l, acik sular icin 0.006 – 1.554 µg/l araliginda olculmustur. Kiyisal sularda diatom (%27) ve siyanobakteriler (%25) baskin iken, acik sularda siyanobakteriler (%35) ve primnesiyofitler (%27) fitoplankton kompozisyonuna daha fazla katki yapmistir. Diatomlarin acik sularda fitoplankton kompozisyonuna yaptigi katkinin kis ve bahar aylarinda az da olsa varligini arttirdigi belirlenmistir. Ayrica kiyisal sularda kis mevsiminden sonra siyanobakterilerin fitoplankton kompozisyonuna yaptigi katkiyi arttirdigi belirlenmistir. Ana gruplarin fitoplankton kompozisyonuna yaptigi katki kiyaslandiginda, prokaryotik pikoplankton’un kiyi ve acik sularda yaz ve guz doneminde baskin oldugu, kis ve bahar donemlerinde kiyisal sularda baskin olan buyuk okaryotlarin acik sularda ayni donemde yerini okaryotik nanoflagellatlara biraktigi belirlenmistir. Nehir girdilerinden etkilenen kiyisal sularda buyuk okaryotlarin varligi ve tuzluluk arasinda yuksek oranda anlamli negatif iliski bulunmustur.