Assessment of trace metals concentrations in zooplankton from the Edremit Bay (Northeastern Aegean Sea, Türkiye)

The aim of this study was to evaluate the temporal (April & November, 2015) and spatial (point stations & transect lines) status of metal concentrations in zooplankton from the Edremit Bay, Aegean Sea, as well as utilization of zooplankton as a bio-indicator for metal pollution in the study area. The samples were freeze-dried and analyzed in atomic absorption spectrometers. Metal concentrations in zooplankton ranged between Hg:0.30–0.13, Cd:0.51-13.6, Pb:7.76-2364, Cr:3.50-80.4, Cu:9.52-149, Zn:383-4894, Mn:24.3-723 and Fe:1502-130652 mg kg −1 dry weight. The mean concentration of metals decreased in the order of Fe > Zn > Pb > Mn>Cu > Cr > Cd > Hg. Mean metal concentrations were higher at point stations compared to transects sampling lines. Metal Pollution Index (MPI) values in the spring were higher than in the autumn. The highest MPI values were found at the southern and eastern coasts of the bay in the spring which could be related to increased metabolic activity, growth, and food uptake in spring season. The high accumulation degrees of metals in zooplankton could be related to presence of mining sites, industrial facilities, wind-driven currents, and streams in Edremit Bay. This study provides a valuable information for further researches on bioaccumulation of metals by zooplankton in the Aegean Sea. •Metal bioaccumulation in zooplankton of Edremit Bay was studied for the first time.•Bioaccumulation pattern of metals was found as Fe > Zn > Pb > Mn>Cu > Cr > Cd > Hg.•Highest MPI values were detected in the spring.•Mean metal levels at point stations were higher than transect sampling lines.•This study provides a reference background for future studies.