Effects of Stream Channelization on Fish Populations in the Buena Vista Marsh, Portage County, Wisconsin
File(s)
Date
1976-09Author
Headrick, Michael R.
Publisher
University of Wisconsin-Stevens Point
Metadata
Show full item recordAbstract
Fish populations from 6-8 year old ditches and 52-62 year
old ditches within the Portage County Drainage District were
compared with populations in adjacent portions of natural streams.
Two study areas were selected, the upstream zone of good brook
trout ( Salvelinus fontinalis) habitat and the other downstream
in marginal trout waters where white sucker ( Catastomus
commersoni) were more numerous. Each area included new
ditch, old ditch and natural stream , all of similar discharge.
Estimates of annual production by brook trout, population and
biomass estimates of brook trout and white sucker, and total catch
records for other fish species were derived from electrofishing
samples in June, August and September, 1974 and April-May,
July and September, 1975. A creel survey was conducted
during the 1975 trout season.
Loss of year-round instream cover through channelization
limited brook trout density, which reduced annual production by
brook trout to 28.8 kg/ stream km in the upstream new ditch
study area as opposed to 72.2 kg/km in the upstream old ditch
and 65.5 kg/km in the upstream natural stream. Angler success
was also reduced, from 1.03 trout/hr in the upstream old ditch
and 1.05 trout/hr in the upstream natural stream to 0.26 trout/hr
in the upstream new ditch o Approximate equality of these parameters in the upstream old ditch and natural stream indicated
that recovery of natural channel morphology and trout carrying
capacity was nearly complete after 60 years. Midsummer water
temperatures reached upper lethal levels for brook trout in the
downstream ditches, where current velocity was reduced and white
sucker were abundant. Mottled sculpin (Cottus bairdi} were
consistently absent from the upstream new ditch and scarce in the
downstream new ditch. Natural stream had the greatest number of
fish species in both study areas (12 upstream and 18 downstream),
and new ditch had the fewest (9 upstream and 11 downstream).