In coastal parts of the study areas, heavy metals containing ground water flows along the faults and fractures and reaches at sea. In these contaminated waters, morphologically abnormal individuals of the affected meiofauna (benthic foraminifera, ostracod, mollusc) can be found. Three cores were taken from the seafloor in the four separate stations that are located in NW of Ayvalik village, around Alibey and Maden islands, and one core of each three core groups was studied in order to investigate the aforementioned morphological affects on the recent meiofauna, which have been inhibited in those contaminated waters. Lead, manganese, hematite and limonite deposits with small reserves were present in Alibey, Maden and Kiicilk (Small) Maden islands. Morphological changes and coloring were observed in tests of large number of Peneroplis, Lobatula, Ammonia and Elphidium samples collected from these areas. This observation vindicates impact of heavy metals onto the foraminifera assemblages. Heavy metals and other chemical and radioactive elements found in the surrounding country side have been naturally transported into the adjacent sea water during the past and present. The aim of this study is to figure out the effects of the chemical and radioactive elements, which were carried from the land on the meiofaunal (benthic foraminifera, ostracod and mollusc) assemblages. (C) 2017 Elsevier Ltd. All rights reserved.