ASSESSING BENTHIC ANIMAL AND WATER PLANT USE IN ESTIMATING RIVER AL AND CR CONTAMINATION IN THE KINOKAWA RIVER CATCHMENT.

Benthic animals and water plants species useful for devising an index to indicate the extent of Al and Cr contamination in the Kinokawa River catchment area were studied. Studies revealed that the Al concentrations in crane fly larvae (260 to 5,260 mg/kg-dry) and bryophytes (640 to 20,000 mg/kg-dry) around a closed Cu mine were about 1.5 times higher than those around a non-mine area (530 to 3,100 for crane fly larvae and 220 to 13,000 mg/kg-dry for bryophytes). Cr concentrations in dragonfly larvae around the serpentinite (3 to 30 mg/kg-dry) were about 3 times higher than those around the non-serpentinite area (0.6 to 9 mg/kg-dry). Cr concentrations in bryophytes around the serpentinite (3 to 91 mg/kg-dry) were about 1.5 times higher than those around the non-serpentinite area (2 to 53 mg/kg-dry). Al concentrations in Pottiaceae, a kind of bryophyte found around a closed Cu mine (890 to 20,000 mg/kg-dry) were about 2.5 times higher than those around a non-mine area (6,300 to 8,000 mg/kg-dry). Cr concentrations in Pottiaceae found around the serpentinite area (91 mg/kg-dry) were about 3 times higher than those around the non-serpentinite area (3 to 29 mg/kg-dry). Additionally, crane fly larvae, dragonfly larvae, bryophytes, and Pottiaceae were widely distributed as they were sampled around both contaminated and non-contaminated areas. Therefore, it was concluded that useful species for devising an index to indicate contamination included the crane fly larvae for Al, dragonfly larvae for Cr, and the bryophytes, especially Pottiaceae for Al and Cr. [ABSTRACT FROM AUTHOR]