Evaluating Oxidative Stress Biomarkers in Thicklip Grey Mullet (Chelon labrosus) at İzmir Bay

In this study, we investigated the oxidative stress-related biomarkers (catalase and malondialdehyde) on selected tissues (liver, gills, and muscle) of Chelon labrosus in İzmir Bay to evaluate spatial differences between Inner and Outer Bay.C.labrosus specimens were collected by fishing at both Inner Bay (İnciralti) and Outer Bay (Foça) in December 2019. Liver, gills, and muscle tissues were separated and rapidly placed in the liquid nitrogen tank (-198°C). Catalase (CAT) and malondialdehyde (MDA) levels were determined spectrophotometrically by using a microplate reader.Mean CAT levels (U/mL) were found in muscles as 0.181 in gills as 0.779 and in livers as 0.622 at the Inner Bay. On the other hand, CAT levels were detected in muscles as 0.265, in gills as 1.093, and in livers as 0.666 at the Outer Bay. Also, mean MDA contents (pmol MDA/mg tissues) were determined in muscle tissues as 0.0191, in gills as 0.0768, in livers as 0.0372 at the Inner Bay. MDA contents were found in muscle tissues as 0.0385, in gills as 0.1045, in livers as 0.0588 at the Outer Bay. Therefore, biomarker levels in Outer Bay results are generally higher than Inner Bay.According to the ANOVA and Tukey post-hoc tests, significant differences between tissues and locations were observed for MDA. Also, statistical differences were found between only tissues for CAT, however, no significant differences were detected between locations.It’s known that these biomarkers (CAT and MDA) are indicators of pollution status in the marine environment. Inner Bay of İzmir has affected negatively harbor activities and urbanization. Also, biomarker results showed that Outer Bay is under threat of pollution by the Gediz River and other anthropogenic activities. Therefore, biomonitoring researches should be maintained in İzmir Bay for ecological risks and human health.Keywords: Biomarkers, catalase, malondialdehyde, Chelon labrosus, İzmir BayT22ABSTRACT</p

Deniz Suyunda Amonyum Analizinde Reaksiyon Parametrelerinin Deneysel Tasarım Metodu ile Optimizasyonu

.</p

Distributions and Sources of PAHs and OCPs in Surficial Sediments of Edremit Bay (Aegean Sea)

In this study, levels, distributions, and sources of polycyclic aromatic hydrocarbons (18 compounds) and organochlorine pesticides (19 compounds) in surface sediments of 14 stations from Edremit Bay (Aegean Sea) were investigated in April and November 2015. Sigma PAH concentrations (0.65-175ng/g) in Edremit Bay sediments indicated low pollution. Sigma PAH levels were decreased in the order of inner (81.1 +/- 47.0ng/g), northern (48.4 +/- 15.9ng/g), and southern (19.0 +/- 15.8ng/g) bays. p,p'-DDE was the only organochlorine pesticide detected in Edremit Bay sediments and found between nd to 1.16ng/g dw. According to sediment quality guidelines, PAHs and p,p'-DDE levels in Edremit Bay were below the threshold effect level, effect range low, and threshold effect concentration limits and the sediments have no potential ecological risks. Two- to 3-ring PAHs were found at higher levels than 4- to 5-ring PAHs. Molecular PAHs ratios and Principal Component Analysis-Multiple Linear Regression analyses indicated combustion of wood-coal and vehicle emissions might have contributed to PAH levels in the bay

Assessment of marine pollution in Izmir Bay: Nutrient, heavy metal and total hydrocarbon concentrations

Izmir Bay (western Turkey) is one of the great natural bays of the Mediterranean. Izmir is an important industrial and commercial centre and a cultural focal point. The main industries in the region include food processing, oil, soap and paint production, chemical industries, paper and pulp factories, textile industries and metal processing. The mean concentrations showed ranges of 0.01 -0.19 and 0.01 - 10 mu M for phosphate, 0.10-1.8 and 0.12-27 mu M for nitrate+ nitrite, and 0.30-5.8 and 0.43-39 mu M for silicate in the outer and middle-inner bays, respectively. The TNOx/PO4 ratio is significantly lower than the Redfield's ratio and nitrogen is the limiting element in the middle-inner bays. Diatoms and dinoflagellates were observed all year around in the bay and are normally nitrogen limited

Metal contamination in surficial sediments of Edremit Bay (Aegean Sea): Spatial distribution, source identification and ecological risk assessment

Seasonal and spatial distributions of metals in surficial sediments of Edremit Bay (Aegean Sea, Turkey) were investigated to determine contamination status, possible sources and ecological risks in the study area. Seasonal (autumn and spring) surface sediment samples were collected in 2015 with a box-corer from 14 stations. Metal concentrations (Hg, Cd, Pb, Cr, Cu, Mn, Zn, Fe, Al), grain size distributions and organic carbon levels were determined in samples. Metal levels were analyzed with flame (Pb, Cr, Cu, Mn, Zn, Fe, Al), cold-vapor (for Hg) and graphite furnace (for Cd) atomic absorption spectrometer after microwave digestion. Ranges of metal concentrations in Edremit Bay sediments were Hg: 0.03-017, Cd: 0.10-0.27, Pb: 5.32-47, Cr: 66-219, Cu: 13-57, Mn: 382-729, Zn: 66-154, Fe: 18685-50539 and Al: 10244-82819 mg/kg dry weight. Enrichment factor, geo-accumulation index, and contamination factor values were calculated, and the results indicated the presence of moderate Pb, Cr and Zn pollution in the sediments. According to sediment quality guidelines (threshold and probable effect levels), sediments were moderately to heavily polluted with Cr and Mn, and no potential harmful effects of Cd, Hg, Zn, Pb and Cu were found for aquatic organisms. Statistical analyses and risk assessments suggested that natural processes (i.e. streams, springs and rain run-offs) and anthropogenic inputs (i.e. mines, agricultural activities and domestic effluents) may have contributed to the metal levels in surficial sediments of Edremit Bay. (C) 2020 Elsevier B.V. All rights reserved

Seasonal variations of multi-biomarker responses to metals and pesticides pollution in M. galloprovincialis and T. decussatus from Homa Lagoon, Eastern Aegean Sea

Biomarkers (CAT, SOD, GPx, and AChE) were investigated in hepatopancreas and soft tissues of mussels (Mytilns galloprovincialis) and clams (Tapes decussatus) in response to metal and pesticide pollutions in Homa Lagoon. Mussel and clam samples were seasonally collected in January, May, August and November 2015. According to the results, higher metal concentrations determined in the soft tissues of both species in January. Hepatopancreas was found to accumulate higher levels of metals than soft tissue. Metal deposition potential in clams were higher than mussels. Pesticide levels were below detection limits in clams. In mussels, only 4,4'-DDE was detected in soft tissues and hepatopancreas in November. Highest AChE, CAT, SOD and GPx activities in mussels were determined in January. On the other hand, maximum AChE and CAT activities in clams were found in November. Seasonal variations of metals and biomarker levels might be related to species-specific physiology and environmental conditions