Assessment of health risks due to toxic metals in demersal fish captured from Saros and Edremit Bays, Northern Aegean Sea.

Bays are vulnerable ecosystems generally located near densely populated areas where toxic metals tend to accumulate and stay longer, affecting marine life. This study aimed to investigate the age-based health risks arising from Hg, Cd, Pb, and As in demersal fish captured from two major bays in the Aegean Sea. For this purpose, red mullet, whiting, piper gurnard, and tub gurnard, frequently consumed species, were caught from Saros and Edremit Bays. Toxic metal concentrations were determined from the muscle tissue of fish. Health risk assessments were conducted by the estimation of weekly intake (EWI), provisional tolerable weekly intake (PTWI), target hazard quotient (THQ), total THQ (TTHQ), and target carcinogenic risk (TR). Red mullet from Edremit Bay was the species with the highest toxic metal levels, which were 1.597 mg/kg, 0.041 mg/kg, 0.070 mg/kg, and 19.351 mg/kg for Hg, Cd, Pb, and As, respectively. Whiting from Edremit Bay had higher mean concentrations of Hg and As than those from Saros Bay. The levels of Hg, Pb, and As (0.328, 0.043, and 0.574 mg/kg) in the tub gurnard were higher in comparison with the piper gurnard (0.252, 0.020, and 0.382 mg/kg) caught in the same station in Saros. TTHQs of red mullet and whiting from the same bay were found to be > 1, indicating potential health risks for all nine age categories studied. On the other hand, TTHQs of all species from Saros Bay were determined to be > 1 for the first four age categories, which might trigger health risks for children and adolescents. According to the TR index for Pb, no risk was determined for the fish from both bays. However, TR calculations for inorganic As indicated high cancer risk in most of the age categories for red mullet and whiting from Edremit Bay. To sum up, the results revealed that the fish captured from Edremit Bay posed serious health risks in terms of Hg and As concentrations for all nine age categories. Surveillance and monitoring of toxic metal levels in demersal fish and population-based health risk evaluation are vital in heavily populated bays.

Pollution characteristics, sources and health risks assessment of potentially hazardous elements in sediments of ten ponds in the Saros Bay region (Türkiye).

Pollution of lentic ecosystems by potentially hazardous elements (PHE) due to human activities has become a global concern. In this study, the contents of eight PHEs in the sediments of 10 most important ponds located in the Saros Bay region (Türkiye) were evaluated. The contents of PHEs in the sediments of the ponds ranged from 0.14 mg/kg for Cd to 274 mg/kg for Mn. According to the enrichment factor (EF) results, ponds P3, P8 and P9 for Cd and pond P8 for Pb showed "moderate enrichment". However, the pollution load index (PLI) results indicated that all ponds were in a "baseline contamination" state due to the combined effect of all PHEs. Similarly, based on ecological risk assessment indices, no ecological risk from PHEs was identified. In addition, Cd, Zn, As, Cr, Cu and Pb contents in all ponds were found below threshold effect concentrations. The results of the health risk assessment indicated that non-carcinogenic and carcinogenic risks were not expected for recreational receptors due to exposure to the PHEs in the sediments via incidental ingestion and dermal contact. Correlation and cluster analysis results indicated that although agricultural activities contributed slightly to the As content, all PHEs mainly originated from natural sources.

Fecundity of chub mackerel (Scomber japonicus Houttuyn, 1782) in the Aegean Sea / Fecundidade da cavala (Scomber japonicus Houttuyn, 1782) no Mar Egeu

This study was carried out in April - June 2014 to determine absolute fecundity (F) of the chub mackerel (Scomber japonicus Houttuyn, 1782) in Saros Bay (Aegean Sea, Turkey). The relations between the absolute fecundity and total length, total weight and age of the chub mackerel females were estimated as F=0.0318TL4.81, F=1573.9TW- 42858 and F=109607A-136129, respectively. This study aims to contribute to the reproductive biology of S. japonicus by reporting the first findings about the absolute fecundity of the species for the Aegean Sea.

Este estudo foi realizado em abril-junho de 2014 para determinar a fecundidade absoluta (F) da cavala (Scomber japonicus Houttuyn, 1782) na Baía de Saros (Mar Egeu, Turquia). As relações entre a fecundidade absoluta e comprimento total, peso total e a idade da cavala fêmeas foram estimados como F=0.0318TL4.81, F=1573.9 TW- 42858 e F=109607A-136129, respectivamente. Este estudo visa contribuir para a biologia reprodutiva de S. japonicus, apresentando as primeiras conclusões sobre a fecundidade absoluta das espécies para o Mar Egeu.

Fecundity of Chub Mackerel (Scomber japonicus Houttuyn, 1782) in the Aegean Sea

Abstract This study was carried out in April - June 2014 to determine absolute fecundity (F) of the chub mackerel (Scomber japonicus Houttuyn, 1782) in Saros Bay (Aegean Sea, Turkey). The relations between the absolute fecundity and total length, total weight and age of the chub mackerel females were estimated as F=0.0318TL4.81, F=1573.9TW- 42858 and F=109607A-136129, respectively. This study aims to contribute to the reproductive biology of S. japonicus by reporting the first findings about the absolute fecundity of the species for the Aegean Sea.

Resumo Este estudo foi realizado em abril-junho de 2014 para determinar a fecundidade absoluta (F) da cavala (Scomber japonicus Houttuyn, 1782) na Baía de Saros (Mar Egeu, Turquia). As relações entre a fecundidade absoluta e comprimento total, peso total e a idade da cavala fêmeas foram estimados como F=0.0318TL4.81, F=1573.9 TW- 42858 e F=109607A-136129, respectivamente. Este estudo visa contribuir para a biologia reprodutiva de S. japonicus, apresentando as primeiras conclusões sobre a fecundidade absoluta das espécies para o Mar Egeu.