MONITORING AQUATIC ENVIRONMENTS RECEIVING INDUSTRIAL EFFLUENTS USING SMALL FISH SPECIES-1 - RESPONSE OF SPOONHEAD SCULPIN (COTTUS RICEI) DOWNSTREAM OF A BLEACHED-KRAFT PULP-MILL
Wn. Gibbons et al., MONITORING AQUATIC ENVIRONMENTS RECEIVING INDUSTRIAL EFFLUENTS USING SMALL FISH SPECIES-1 - RESPONSE OF SPOONHEAD SCULPIN (COTTUS RICEI) DOWNSTREAM OF A BLEACHED-KRAFT PULP-MILL, Environmental toxicology and chemistry, 17(11), 1998, pp. 2227-2237
Larger fish species may not always be suitable for monitoring the resp
onse to industrial effluents because they are mobile and capable of ex
tensive movement beyond effluent exposure areas. Spoonhead sculpin (Co
ttus ricei) was collected upstream and downstream of a large bleached-
kraft pulp mill on the Athabasca River, Alberta, Canada, during fall a
nd spring periods to determine whether small, sedentary fish species d
emonstrate responses reflecting local exposure conditions. During the
fall sampling period, exposed fish were older and larger than upstream
fish and showed increases in condition, gonad size, egg weight, liver
weight, and hepatic mixed function oxygenase activity (7-ethoxyresoru
fin O-deethylase [EROD]). Sculpin collected from the opposite river ba
nk, where exposure was reduced, showed condition factors, gonad size,
egg weight, liver weight, and EROD activity that were not significantl
y different from reference sites or intermediate between reference and
downstream values. In the spring after a prolonged overwinter exposur
e to higher effluent concentrations, exposed fish were larger, showed
increased size-at-age, condition, liver weight, ovary size, and EROD a
ctivity. Far-field collections showed that most responses persisted do
wnstream for at least 48 km. The general response of exposed spoonhead
sculpin was consistent with a nutrient enrichment effect described in
studies investigating water quality, algal growth, and benthos commun
ities at this site but also may be related to reduced competition asso
ciated with the loss of older fish observed in the spring. The use of
small species for sentinel monitoring provided a viable alternative to
use of larger, more mobile species.