In the Gulf of Bothnia the fourhorn sculpin (Myoxocephalus quadricornis) demonstrated elevated levels of deformed spine and/or vertebrae in areas polluted by bleached kraft mill effluents (BKME). Laboratory tests confirmed a correlation between the observed defects and BKME, diluted about 200-1000 times. Analysis of mechanical parameters (strength, elasticity etc) and chemical composition (Ca, P, collagen, proline, hydroxyproline) of single vertebrae confirmed the effects of BKME on bone characteristics in feral and laboratory exposed fourhorn sculpin. Similar effects were recorded also for feral perch (Perca fluviatilis) caught in the vicinity of a pulp mill and bleak (Alburnus alburnus) exposed to various BKME in the laboratory.
After about 4 1/2 months of exposure to 0.1 and 0.5 mg tetrachloro-1,2-benzoquinone/L fourhorn sculpin demonstrated vertebral deformities and aberrant mechanical properties of vertebrae. The results are discussed in relation to results obtained from feral fish exposed to BKME and fish exposed to BKME in the laboratory.
The recorded effects are suggested to be the results of long-term metabolic dysfunction, leading also to other serious effects in the organism.