Spatio-temporal distribution of microplastic abundances in Izmir Bay (eastern Aegean Sea).

Microplastics (MPs) and their impacts have been extensively studied in the Mediterranean region. However, more research has yet to be conducted on assessing the extent of microplastic (MP) pollution in the eastern Aegean Sea, specifically in Izmir Bay. This study aims to evaluate the current state of MP pollution in surface water and sediment samples collected from Izmir Bay. Ten sampling stations were specifically selected, including locations near stream discharge points, maritime transportation piers, and port areas. Surface water samples were collected using a manta trawl net, while sediment samples were obtained using a Van Veen grab. The mean MP abundances in surface water ranged from 1,083,882 to 8,091,684 items/km2. Fragment type MPs were dominant. In terms of size category, it was found that MP s of 500µm size were dominant. The dominant color of MPs was white. ATR-FTIR analyses revealed that polyethylene and polypropylene were the dominant polymer types. MP concentrations in sediment ranged from 2,125 to 4,925 items/m2, with fiber-type MPs being the most abundant. Black-colored MPs were found to dominate in sediment samples. Overall, the MP levels in Izmir Bay were higher than previous studies findings. Therefore, it is crucial to conduct long-term monitoring studies to obtain more consistent and reliable data on MP pollution levels in Izmir Bay.

Temporal trends of some trace metals in Lithophaga lithophaga (L., 1758) from Izmir Bay (Eastern Aegean Sea).

This study compared the levels of the trace metals zinc (Zn), cadmium (Cd), lead (Pb) and copper (Cu) in the bivalve Lithophaga lithophaga from Izmir Bay (Aegean Sea) between 2001 and 2011. Comparisons were made on the basis of season, as well as year. All values were measured by voltammetry. Median values of trace metals for all seasons in 2011 were 244.67 µg Zn g(-1), 1.09 µg Cd g(-1), 7.64 µg Pb g(-1) and 56.03 µg Cu g(-1) as dry weight. The results showed a general trend of decreasing Zn, Pb and Cu concentrations over time, but an increasing trend for Cd. Mean trace metal concentrations in individuals of L. lithophaga in 2011 exceeded the permissible limit published in the Turkish Food Codex for Pb, and closely approached the limit for Zn. The mean Cd concentration was within the permissible limit of the Turkish Food Codex, but exceeded the limit of the World Health Organization. Levels of Cu were within permissible limits of published regulations.

The 210Po and 210Pb levels in surface sediment samples in the Izmir Bay (Aegean Sea-Turkey).

Bottom sediments reflect in general the relative contamination of a sea area. Therefore, a great deal of monitoring work has been dedicated to the analysis of bottom sediments. Izmir Bay is a very important pollution centre in Turkish Aegean coast region due to a densely populated community, industrial complex and maritime transportation, and there are many streams flowing into the bay that pass through a number of industrial and agricultural areas. It had received the majority of domestic and industrial wastewaters until the wastewater treatment plant was constructed. It is well known that sediments play an important role as reservoirs of a fraction of the pollution in aquatic systems. Therefore, sediment samples were collected monthly from three stations which are located in the inner part of the bay during the period January to December 2003. Temporal variations and seasonal changes on their (210)Po and (210)Pb contents were examined, and the activity concentrations of (210)Po and (210)Pb were found to vary from 43+/-6 to 132+/-12 and 27+/-5 to 91+/-9 Bq kg(-1) dry wt, respectively. The highest values of those natural radionuclides were measured at Karsiyaka Station because of the current systems of the bay. Seasonally, the (210)Pb levels were found to increase during the winter time for all the stations.

Spatio-temporal variations of organic carbon and chlorophyll degradation products in the surficial sediments of Izmir Bay (Aegean Sea/Turkey).

The aim of this research is to determine the effects of Izmir Big Channel Waste Water Treatment Project on the sediment quality of Izmir Bay. Wastewater treatment improves the water quality. However, sediment does not respond to this treatment as fast as water column. Monitoring of bottom water and sediment quality is necessary for identification of the recovery of the whole ecosystem. For this purpose, bottom water and sediment samples were collected from three stations which are located in the middle and inner parts of the Izmir Bay on a monthly basis between January 2003 and December 2003. Values measured at stations ranged between; 0.54-12.82 microg/L for chlorophyll-a, 0.09-9.32 microg/L for phaeopigment, 0.05-1.91 mg/L for particulate organic carbon in bottom waters, 11.88-100.29 microg/g for chlorophyll degradation products and 1.12-5.39% for organic carbon in sediment samples. In conclusion, it was found that grazing activity explained carbon variations in sediment at station 2, but at station 1 and station 3 carbon variations in sediment were not related to autochthonous biological processes.

Effects of Cadmium (CdCl(2)) on development and hatching of eggs in European squid (Loligo vulgaris Lamarck, 1798) (Cephalopoda: Loliginidae).

This is the first study related to the effects of cadmium (Cd) on the development and hatching of eggs of Loligo vulgaris. The eggs were exposed to concentrations varying from 10 to 100,000 microg Cd/l for up to 1 month. During the study period natural sea water salinity (37 PSU), ambient temperature (ranging 16.5-21.5 degrees C) and light conditions of 12-h light: 12-h dark for 744-h were used prior to the hatching. For 96-h, mortality rate of 100% of the eggs was found at cadmium concentration of 100,000 microg Cd/l, and the same mortality rate of the eggs were found at 1,000 and 10,000 microg Cd/l for 744-h and 696-h, respectively. Hatching took place between hours 456 and 576 in the control group and between hours 480 and 576 in 10 and 100 microg Cd/l groups. Total hatching rates were calculated to be 98.2 +/- 1.6% for control group, 99.4 +/- 0.6% for 10 microg Cd/l group and 98.6 +/- 1.2% for 100 microg Cd/l group. Hatching successes were estimated as 69.5 +/- 13.8% for control group, 84.5 +/- 8.2% for 10 microg Cd/l group and 76.9 +/- 5.9% for 100 microg Cd/l group. In the 100,000 microg Cd/l treatment, the egg degeneration began from animal pole of the eggs in 16 h, and 50% and 100% of them died in the initial stage at 72-h and 96-h, respectively. In the 10,000 microg Cd/l group, the eggs which reached at stage 19 (IX) were deformed and 50% and 100% of them died at 312-h and 696-h, respectively. In 1,000 microg Cd/l group, however, the eggs developed abnormally from stage 21 (X-XI) and reached at stage 29 (XIX), and 50% and 100% of them died in 624-h and in 744-h, respectively. There were significant differences in survival rates of the eggs among the concentrations (p < 0.05). The current study demonstrated that Cd adversely affects the development, survival and hatching of L. vulgaris eggs; however, no mortality was observed in 10 microg Cd/l and 100 microg Cd/l groups.

Trace metal levels in mussels (Mytilus galloprovincialis L. 1758) from Turkish Aegean Sea coast.

Bio-monitoring of some heavy metal levels (Cd, Pb, Zn, Cu) in whole edible soft parts of Mytilus galloprovincialis (L. 1758) was conducted in Turkish Aegean Sea coast during the period of September 2002-August 2003 seasonally. Moreover, some physico-chemical environmental parameters, also have been analysed in the same region. The values of some physico-chemical environmental parameters in coastal waters of Turkish Aegean Sea were changed between; 9.0-27.0 ( composite function)C for temperature, 31.93-40.45 psu for salinity, 7.35-8.48 for pH and 4.05-9.50 mg/l for dissolved oxygen. The levels of trace elements in whole edible soft parts including interstitial fluids of Mediterranean mussels M. galloprovincialis (L. 1758), sampled from 6 different regions of Turkish Aegean Sea coast have ranged between; 0.04-0.52 microg Cd/g wet weight, 0.49-1.72 microg Pb/g w.w., 0.95-1.85 Cu/g w.w., 16.11-37.15 microg Zn/g w.w. The highest values for all trace metals (Cd, Pb, Zn, Cu) were measured in inner part of Izmir Bay (station 3) and lowest in Sigacik and Gulluk Bay (station 5, 6). Generally heavy metal levels are lower than the results in soft mussel tissues reported from Mediterranean regions.