Commercial and Sport Fisheries for Lake Whitefish
in Michigan Waters of Lake Superior, 1983-96
Richard G. Schorfhaar
Charlevoix Fisheries Station
96 Grant Street
Charlevoix, MI 49721-0117
Philip J. Schneeberger
Marquette Fisheries Station
484 Cherry Creek Road
Marquette, Michigan 49855
Abstract.–Lake whitefish were harvested in Michigan waters of Lake Superior by state-licensed commercial trap
netters, tribal commercial gill netters, and sport anglers. Catch and effort
statistics were obtained from state summaries, tribal reports, and creel survey
estimates. Biological data were analyzed for trap net and sport fisheries.
Commercial catches increased from 1983 to 1986, fluctuated between 1987 and
1992, then generally decreased through 1996. Average annual commercial catch was
354,364 kg during 1983-96. Average annual sport catch at Keweenaw Bay,
Marquette, and Munising was less than 4,000 fish (~2,000 kg) during 1985-96.
Total annual mortality rates were generally below the target maximum rate of 55%
at Ontonagon, Big Bay, Marquette, Munising, and Grand Marais. Higher mortality
rates were estimated for Upper Entry and Keweenaw Bay stocks. Weight-length
regression coefficients and von Bertalanffy growth coefficients were generally
similar regardless of fishing area or year. Calculations of total allowable
catch did not match actual harvests, mostly because commercial fishing effort
was variable and unpredictable from year to year. Annual estimates of mean
length and mean age of fish in trap-net catches were greater than means for
sport-caught fish. Compared to sport-caught whitefish, those in trap nets were
significantly longer for ages near the age of recruitment to commercial gear
(age 5) at Marquette, and for a broader range of ages at Munising. At Keweenaw
Bay there were instances where sport-caught fish were longer at age than those
in trap nets. Among like-aged fish from different fishing areas, whitefish from
Marquette and Munising were generally longest for commercial fisheries and those
from Keweenaw were longest for sport fisheries. Length-at-age was generally
greatest in 1983 and 1984 for lake whitefish in trap nets, and in 1988 for sport
catches. There did not appear to be much conflict between sport and commercial
trap-net fisheries where they occurred together.