Which Organism is More Suitable As A Toxic Metal Accumulation Bioindicator – Fishes Or Diatoms: A Case Study Of An A Class Wetland In Northwest Türkiye Under Effect Of An Intensive Paddy Cultivation Stress?

Abstract

In this research, “diatoms” as the first step and “fishes” as the last step of the food chain were compared as the toxic metal accumulation bioindicator in an A Class wetland in Turkey. Toxicant bioaccumulations were determined in liver, gill and muscle tissues of 2 commercially consumed fish species "Carassius gibelio" and "Cyyprinus carpio" and in frustules of epiphytic diatom communities living on submerged macrophytes. Samples were collected from the Gala Lake, which is among the best stopover habitats of birds migrating between Europe and Africa, seasonally considering the paddy harvest period, which is a major stress factor for the ecosystem. Also potential human health risks associated with the consumption of fishes and consumption – dermal contact of diatoms were evaluated both for summer – before paddy harvest (BPH) and autumn – after paddy harvest (APH) periods. As a result of this research, the investigated toxic metal bioaccumulation levels were increased significantly in diatoms in the APH period, while less significant exchanges were recorded in fish tissues, in general. The data showed that the diatoms are much more sensitive to changes in the environmental conditions than fishes and they are more effective biological tools as toxic metal accumulation bioindicators than fishes.