Northeastern Mediterranean Coast Research Articles

Planktonic dinoflagellates of the northern Levantine Basin, northeastern Mediterranean Sea

In the present study, a checklist of planktonic dinoflagellates was prepared from studies conducted on the northeastern Mediterranean coast of Turkey and by evaluating previously conducted studies. The sampling areas included İskenderun Bay, the coast near Karataş at the west end of the Bay, and Babadıllimanı Bight, situated at the west of Mersin Bay, and its surroundings. The data of the present study derives from over 90 locations visited between 1994 and 2004. A total of 174 taxa were reported. Ceratium (57 taxa) and Protoperidinium (28 taxa) were the most species-rich genera. The most common taxa were Ceratium kofoidii, Ceratium trichoceros, Ceratium tripos var. atlanticum, Protoperidinium divergens, Protoperidinium steinii, Ceratocorys horrida, Goniodoma acuminatum and Gonyaulax polygramma. Toxic species such as Dinophysis caudata, Dinophysis tripos were reported, and Scrippsiella trochoidea and Prorocentrum micans, which are known as red tide species elsewhere, were also common. The number of species is similar to those along other coasts of the Levantine Basin. However, some species were observed that had not previously been reported for the Levantine Basin, which can be attributed to the fact that the number of studies conducted in the region has increased and that new species may have entered the environment.

The coastal roadside vegetation and environmental gradients in the arid lands of Egypt

A recent floristic and environmental survey was undertaken on the roadside verges along the main highway between El Arish and Rafah (31° 10’N, 33° 48’E and 31° 17’N, 34° 15’E) that extend for about 45 km on the northeastern Mediterranean coast of Sinai (Egypt). 63 stands were studied at 700-m intervals to represent the variation of vegetation, and to compile the floristic composition of the study area. Four main landform zones were distinguished (from the seashore inwards) and run parallel to the roadway: (A) coastal plain, (B) saline depressions, (C) sand plains and (D) sand dunes. There is a gradual increase in the total number of recorded species in the recognized landform units. Application of TWINSPAN analysis yielded 18 vegetation groups (VG) that comprised 7 main vegetation types (VT). These vegetation types were (I) Artemisia monosperma in the sand dunes, (II) Artemisia monosperma-Echinops spinosus in the sand plains, coastal plain and sand dunes, (III) Cyperus capitatus-Ammophila arenaria in the sand dunes, (IV) Ammophila arenaria-Pancratium maritimum in the coastal plain, (V) Zygophyllum album, (VI) Arthrocnemum macrostachyum and (VII) Arthrocnemum macrostachyum-Zygophyllum album in the saline depressions. Ordination techniques of Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) were used to examine the relationship between the roadside vegetation and the 8 studied environmental variables: total soluble salts (TSS), pH, calcium carbonate (CaCO3), sand, fine fractions (silt and clay), distance from the seashore (DFS), landform units (LF) and altitude (Alt). Both ordination techniques indicated that soil salinity, calcareous sediments, soil texture, landform, altitude and distance from seashore were the most important factors for the distribution of the vegetation pattern along the road verges in the study area. These gradients were related closely to the first three CCA axes, and accounted for 72.4% of the species relationship among the stands. Low species richness in the vegetation types of the coastal plain and saline depressions may be related to their high soil salinity, while the high species diversity and the highest share of alien weeds of vegetation types characterized the sand dunes may be related to the high disturbance of their substrates as a result of agriculture practising, farming processes and other excessive human disturbances.

Idealized model simulations of barotropic flow on the Catalan shelf

The effect of along shelf variation in shelf width on barotropic shelf edge flows and topographic shelf waves are investigated with a numerical model. The model topography represents a gradual transition from a narrow straight to a broader straight shelf region. It is designed primarily to model the Catalan shelf on the northeastern Mediterranean coast of Spain, but the results obtained here are of general validity and will also apply to shelf flow under similar conditions elsewhere. The numerical experiments are carried out with flow imposed, both steady and oscillatory, at the upstream end of the narrow shelf region. With a prescribed shelf edge flow there is a strong tendency for topographic steering in the transition zone. The adjustment is found to take place on a short time scale of 2–5 days set by propagating wave modes rather than by advection. Bottom friction effects do not lead to significant on-shelf leakage of the flow. Flow instability and eddy formation are found to occur, even in cases where the potential vorticity for the imposed flow does not have a local maximum on the shelf slope. The instability leads to development of anticyclonic eddies on the narrow shelf which undergo strong non-linear adjustment at the transition zone from a narrow to a broader shelf. On the broad section of the shelf near the transition zone there is a tendency for formation of a large anticyclonic eddy. Bottom friction is found to influence the flow instability and the formation of eddies in cases where the flow is marginal for instability and growth of eddies. Particle tracking has been performed in order to study cross shelf mixing and transport. Finally, we have studied the current response due to a concentrated wind stress jet acting perpendicular to the coastline in the transition zone between the narrow and the broad shelf regions. A dipolar eddy structure is found to develop with the axis of the dipole tilting about 30° with the axis of the wind jet and with strong current shear in the zone near the dipole axis.

Gaseous and particulate air pollutants in the Northeastern Mediterranean Coast

The concentrations of sulfur dioxide (SO 2), ammonia (NH 3) and particulate matter were measured for a 6-month period and the concentration of gas phase nitric acid (HNO 3) was measured for a 1-month period in the North-eastern Mediterranean atmosphere (Küçük Çalticak, Antalya) using a ‘filter pack’ system that was developed and optimised in our laboratory. Among all the gas phase pollutants, HNO 3 had the lowest concentration (0.42 μg m −3) followed by ammonia. Most of the measured parameters showed variation in time depending on strengths of source regions and meteorological conditions. Nitric acid is found mostly in particulate form, but gas to particulate partitioning of SO 2 shows seasonal variation. Wind trajectory analyses indicate that the major contribution to the observed concentrations come mostly from Eastern Europe and Blacksea regions as well as the southern sector.

Trace metal levels in fish and crustacea from Northeastern Mediterranean coastal waters

Some fish and crustacea caught near the northeastern Mediterranean coast of Turkey between 1977 and 1980 have been analysed by the AAS technique for their H Hg, Cd, Pb, Zn, Cu, Fe, Ni, Cr and Mn contents. In the crustacea Portunus pelagicus (crab) and Penaeus keratherus (shrimp), the two essential elements Zn and Cu, showed a linear correlation. Among the bony fish, Upeneus moluccensis (gold band goat fish), a member of the Mullidae family, and Portunus pelagicus showed a much greater tendency to accumulate Hg than other species. Although Cr concentrations in the sediments of the area studied were high, Cr levels in the organisms studied were found to be relatively low. The highly toxic metals Hg, Cd and Pb were found to be present in concentrations lower than those reported from other areas of the Mediterranean.