Geological Bulletin of Turkey, vol.52, no.1, pp.31-84, 2009 (Peer-Reviewed Journal)
Four core samples were collected from the vicinity of Alibey and Maden islands on the northwestern of
Ayvalık. 91 sediment samples were obtained from the cores and were analyzed for their recent
foraminifer content. High abundance of individuals with morphological abnormalities were observed in
benthic foraminifer species such as, Peneroplis pertusus, P. planatus, Lobatula lobatula, Ammonia
compacta, A. parkinsoniana, Challengerella bradyi, Elphidium complanatum, E. crispum. The
introduction and deposition of heavy metal with terrestrial origin in marine biota result in an
environmental risk for aquatic life. Environmental pollution became common mainly in the second half
of 20th century, because of dumping of materials, such as manganese, lead and iron to terrestrial and
marine environments. Also managing the ore beds led to significant morphological changes in
foraminiferal assemblages. The abnormal test development observed in foraminifers and presented in
this study are suggested to be the result of biological effects of the heavy metals that reached marine
environment, and this phenomenon can be used as a practical indicator to determine the natural
environmental pollution. The aim of this study is to find out the possible reasons of these morphological
abnormalities, and compare with other factors which are known to cause similar deformations.