Effects of submarine mine tailings disposal on juvenile yellowfin sole (pleuronectes aspen): A laboratory study

Behaviour, survival, and growth studies were conducted in the laboratory on juvenile yellowfin sole (Pleuronectes asper) exposed to mine tailings produced by a pilot plant for a gold mine near Juneau, Alaska. Fish avoided fresh tailings in favour of natural marine sediment (control) and weathered tailings (75 years old). Only when fresh tailings were covered with 2 cm of control sediment did fish prefer control and fresh tailings equally. Survival of fish was similar (p = 0.66) for fish held on all test sediments. Fish held on fresh tailings for 60 d grew significantly (p = 0.013) less than control fish during the first, but not the second, month. Avoidance or short-term reductions in flatfish growth may occur from submarine disposal of tailings. Rapid burial of tailings in areas with high natural sedimentation (e.g., large river mouths) may accelerate recovery of the sea floor.