Cetacean strandings along the coast of Izmir Bay, Turkey

The present paper provides information on the stranding of cetaceans in Izmir Bay, Aegean Sea, between 1992 and 2004. The data were collected opportunistically during sightings and stranding data collection for Monk Seals. A total of 12 cetaceans, namely Bottle-nosed Dolphin, Tursiops truncatus (n=6), Common Dolphin, Delphinus delphis (n=3), - reported for the first time - and Striped Dolphin, Stenella coeruleoalba, (n=3) were found to be stranded

Gulluk lagoon (Aegean Sea, Turkey) ecosystems [Gulluk lagunu (Ege Denizi, Turkiye) ekosistemi]

Gulluk Lagoon has an area of 2500 decares with a depth of 0.5-5.0 m and is connected to Gulluk Bay by a channel. In this study, samplings of phytoplankton and benthos were taken and physico-chemical parameters were recorded monthly during 1993 at 5 stations. The temperature reached a minimum of 10.42°C in January and a maximum of 26.9°C in July, with a mean annual temperature of 19.53±1.511. The salinity in the lagoon ranged from 7.48‰ to 13.92‰ in January and March, respectively with a mean annual salinity of 10.65 ± 0.555. Dissolved oxygen in the sub-surface (0.25 m) water was 5.56 mg 1-1 in June and 9.06 mg 1-1 in February, with an annual mean 7.31 ± 0.331. The Secchi-disk depth was 1.12 m in May and 2.40 m in October. Nutrient measurements revealed moderately high levels of ammonia (ranging from 4.39 to 29.70 µg-at 1-1), low nitrate (0.81 to 17.87 µg-at 1-1), nitrite (0.19 to 1.35 µg-at 1-1), phosphate (0.01 to 0.45 µg-at 1-1), and silicon (0.26 to 6.00 µg-at 1-1). Chlorophyll a distribution generally indicated that productivity was highest in May (21.49 mg 1-1) and lowest in September (0.77 mg 1-1). Melosira moniliformis was the predominant phytoplankton species. All of the stations were characterized by high species diversity. Identification of the benthic species was carried out with 60 samples collected from 5 stations in a of one year period. As result 68 benthi species belonging to 7 taxa (Nemertina, Polychaeta, Oligochaeta, Crustacea, Mollusca, Insecta, Echinodermata) were identified. The polychaetae were numerically dominated by Notomastus latericeus (3737 individuals), followed by Hediste diversicolor (1524 individuals), and Spionidae (sp) (1361 individuals). Economically important fish species in Gulluk Lagoon consist of mullets (Mugil cephalus, M. capito, Chelon labrosus, Liza saliens), Sparus aurata (gilthead sea bream), Dicentrarchus labrax (sea bass), Solea solea (sole), Anguilla anguilla (eel) and Cyprinus carpio (carp), with an annuall yield varying from 10 to 69 tonnes

Posidonia oceanica in the Marmara Sea

The seagrass Posidonia oceanica is a stenohaline species endemic to the Mediterranean Sea, where it normally lives at a salinity of between 36.5 and 39.5 ppt. Surveys carried out at the North-eastern distribution limits revealed large beds in the Dardanelles Strait and isolated beds in the Marmara Sea, where the salinity ranges between 21.5 and 28 ppt. Microsatellite analysis of these low-salinity tolerant P. oceanica beds, show different signs of genetic isolation: excess of heterozygosity and a presence of fixed alleles. These particularities are rarely found in the whole distributional range of the species. Moreover, all the populations considered in the analysis have a very low genetic diversity in comparison with most of the meadows sampled throughout the Mediterranean Sea. Taking into consideration the genetic data, rhizome expansion rate and the actual extent of the isolated beds in the Marmara Sea and knowing the reproductive rate and dissemination characteristics of P. oceanica, we hypothesize that the isolated population of the Marmara Sea has been established since the Middle Holocene, before the catastrophic intrusion of brackish water into the Marmara Sea and the strong and persistent flow coming from the Black Sea. (c) 2008 Elsevier B.V. All rights reserved