Vertebral defects in fourhorn sculpin, <i>Myoxocephalus quadricornis</i> L., exposed to heavy metal pollution in the Gulf of Bothnia

Abstract

Vertebral defects in adult fourhorn sculpin were used to trace heavy metal pollution in the Gulf of Bothnia (Baltic Sea). From 1978 to 1984 a total of 9789 specimens from 22 localities were X‐rayed and analysed for vertebral deformities, e.g., scoliosis, deformation and/or dislocation of individual vertebrae, etc. The frequency of fish with vertebral defects ranged between 4.3 and 39.7%, the highest frequencies being found in the vicinity of a metal ore smeltery (Rönnskärsverken) emitting heavy metals and arsenic. The possible influence of genetic factors, migration, sex, size, age and parasitic infections on the results are discussed and evaluated.