Lithuanian coastal areas of the Baltic Sea are under significant threat of contamination from whole basin of the Nemunas River, Klaipėda port – one of the largest in the region, resorts and oil terminals. Genotoxic contaminants can pose risk to marine organisms and eventually induce changes in whole ecosystem. In situ performed environmental monitoring, which is based on cytogenetic assessment, provides data about the current status of target organisms and can be successfully used for the evaluation of impacts caused by accidental spills and/or release of hazardous contaminants in the marine environment. Number of studies performed in situ in different areas of the Baltic Sea demonstrates, that Platichthys flesus is sensitive and informative bioindicator of genotoxic contamination [1, 2, 3].
The aim of this study was to assess levels of environmental genotoxicity and cytotoxicity in P. flesus at three study sites of the coastal zone of Lithuania (Klaipėda-Būtingė area) in summer of 2016 and in 2019. Selected stations were characterized by different pollution. Būtingė station was located at vicinity of the Būtingė oil terminal, Klaipėda station situated gates of the Klaipėda port and oil terminal and Palanga station – under the influence of the large resort.
The preparation of biological material and evaluation of the geno- (micronuclei and nuclear buds) and cytotoxicity (fragmented-apoptotic and binucleated cells) endpoints were carried out following the earlier described methodology [1].
Assessed frequencies of micronuclei (MN) in fish from Būtingė and Palanga (accordingly 0.36% and 0.19%), were elevated, compare to the data obtained in 2001 (0.2% and 0.15% respectively), when such study was conducted for the first time. In P. flesus specimens collected in Klaipėda station there were measured high (5.5%) and statistically significant increase of nuclear buds (NB) in comparison to other both stations. Significantly increased levels of micronuclei, nuclear buds and fragmented-apoptotic cells were found in fish and bivalves after the oil spill in the Būtingė terminal in November 2001 and January 2008 [3, 4, 5]. Increased NB frequencies were observed in P. flesus from the Gulf of Gdansk and Riga Bay [2, 3]. High levels of NB in erythrocytes were found in fish caught at oil and gas platform zones, aluminum smelter zone, and in mussels after oil spill [4, 5]. Cytotoxic responses between study stations were not statistically significant.
Increased frequencies of geno- and cytotoxicity parameters in P. flesus from investigated sites of the Lithuanian costal zones indicates the presence of pollution with genotoxic agents, which might lead to genome instability, formation of cancer, reproductive disorders, abnormal physiological responses, increase risk of developmental and degenerative diseases, hereby affect biodiversity [6]. In order to achieve good environmental status, continuous investigations of the biological effects of environmental pollution in marine coastal ecosystems are essential.