Michigan Department of Natural Resources
Gogebic County (T44N, R41W, Sec. 1,2,3,10,11,12)
Surveyed May, 1990 and June, 1992
William L. Deephouse
Thousand Island Lake is part of the Cisco Chain of Lakes located approximately
13 miles southwest of Watersmeet in Gogebic County. The lake is 1,078
acres in size and has a maximum depth of 81 feet (see
map of Thousand Island Lake). Aquatic vegetation is abundant and is
composed mainly of submergent and floating species. Additional fish cover
in the lake includes logs and sunken islands. The shoals are steep and
are composed mainly of sand, gravel, and fibrous peat. There is ample
spawning grounds for all of the lakes' various fish species.
The state maintains a public access site on the east shore. There are
many homes and camps around the lake. There are inlets from Big African
and Lindsley lakes. The lake outlets through Cisco Lake over the Cisco
Lake water level control dam to the Cisco Branch of the Ontonagon River.
Chemical-physical parameters of the lake include a pH of 7.5, a Secchi
disk reading of 12 feet and an methyl orange alkalinity of 50 ppm. The
mid-summer thermocline is at approximately 17 to 26 feet. Dissolved oxygen
levels are too low to support fish below 50 feet during this period.
Thousand Island Lake has a history of fish management dating back to
the early 1930s. Several species of fish, including yellow perch, walleye,
and lake trout, have been stocked through the years.
Being a part of the Cisco Lake Chain, the water level is held artificially
high by a dam on the outlet of Cisco Lake. The dam was constructed sometime
prior to the 1930s and probably originated as a logging dam. In 1937 the
Copper District Power Company purchased the dam and subsequently, in 1948,
the Upper Peninsula Power Company purchased it. The purpose of the dam
to this day is to provide water for power generation at Victoria Dam many
miles downstream on the Ontonagon River. The elevated water level also
permits the passage of boat traffic through several lakes in the Chain
which would not be otherwise possible.
Several fishery surveys have been conducted over the years and all have
resulted in finding quite good populations of walleye, smallmouth bass,
cisco, bluegill, yellow perch, and rock bass. Northern pike also inhabit
the lake but complaints have occurred over the years of numerous small
pike and presently there is no size limit for that species. Muskys have
been reported occasionally.
In recent years, the MDNR has stocked both fry and fingerling walleye
in the Cisco Chain. Additionally, the local lake owners association has
stocked walleye fingerlings. Specifically, 5,000 walleye were stocked
in Thousand Island Lake in 1986 and 15,416 in 1991. In general, fishing
on Thousand Island Lake, as well as the rest of the lakes in the Chain,
has been quite good.
Shifts in the fish community have been documented with periodic surveys
of the fish population. In July 1988, fyke nets were used for 3 days to
sample fish. Results can be compared to a similar fish survey conducted
in 1975. Relative to the 1975 survey, the average length of bluegill had
declined somewhat (5.6 inches compared to 7.1 inches) but the average
length of all other species remained about the same. The percent of catchable
walleye and bluegill declined, but the numbers of catchable perch increased.
The primary predator, walleyes, experienced a major decline in relative
abundance, from 39.6% of the fish biomass in 1975 to 16.8% in 1988. The
abundance of bluegill, rock bass, and smallmouth bass increased significantly.
Largemouth bass and black crappie were taken in the 1988 survey. Their
numbers were not high but neither species had been captured in surveys
in 1969 or 1975. No cisco were captured in the 1988 survey, but this was
not surprising as no gill nets were used. This species is usually pelagic
and is not very vulnerable to fyke nets. Two large northern muskys were
observed in 1988 but neither were measured; one was in the 25 lb range.
A follow-up survey in late May, 1990, found the high bluegill abundance
of 1988 much reduced. They represented only 5% of the total weight of
all fish caught in the survey in 1990 compared to 16.9% in 1988. Average
size had increased to 6.8 inches. Results of the entire 1990 survey are
shown in Table 1.
Most other species taken in the 1990 survey were present in just about
the same numbers as 1988 with the exception of rock bass. They appeared
to have made a significant increase in biomass, going from 10.2% in 1975
to 29.2% in 1988 to 38.1% in 1990. No cisco or largemouth bass were taken.
Overall, the fish community looked to be in good shape and additional
walleye stocking was not recommended. But in the spring of 1991, members
of the Lac Vieux Desert Indian tribe began spearing this lake. A total
of 217 adult walleyes were taken which averaged 16.5 inches long. For
this reason walleye fingerlings were stocked in 1991. The lake was again
speared in 1992 and 215 walleyes were harvested which averaged 16.0 inches.
A safe spearing quota of 224 fish has been set for 1993.
We were interested to see what effect, if any, this tribal walleye harvest
had on the fish community here. A fyke net survey was conducted in mid-June
1992. Results are shown in Table 2.
Although the relative biomass of walleye collected in the survey did
not decline much from 1990 to 1992 (20.4% to 18.4%), walleye numerical
abundance dropped by a factor of three. CPE (catch-per-unit-of-effort)
declined from 4.2 walleye per net-night in 1990 to 1.4 in 1992. The average
size of fish taken increased from 15.4 inches in 1990 to 19.4 inches in
1992. Evidently, the harvest of smaller-sized walleye helped skew the
average size upwards while lowering their overall abundance. Additionally,
it appeared that reproduction has either been limited for the past 2 or
3 years or that the smaller-size classes are being cropped off. Almost
no young-of-the-year or age I walleyes were observed in the October 1991
electrosurvey done by the Great Lakes Indian Fish & Wildlife Commission.
Coincidentally, smallmouth bass numbers also have declined sharply, from
a CPE of 12.2 in 1988 to 5.6 in 1990 to 0.8 in 1992. Combined with the
historically low population of small northern pike, the total biomass
of predators in this lake is declining at an alarming rate. Total biomass
contribution of pike, walleye, and smallmouth bass has declined from 51.4%
in 1975 to 41.9% in 1988 to 39.4% in 1990 to the present low level of
27.2%. This could result in an increase in panfish numbers but of smaller
and smaller average size.
Bluegills, the most abundant panfish, showed only a slight decline in
average size from 1990 to 1992, going from 6.8 inches to 6.2 inches. Their
relative abundance reached an all-time high in 1992, 24.8% by weight.
Black crappie also appear to be increasing at a rapid rate. Their biomass
contribution increased from 2-3% in 1988-92 to 14.2% in 1992. Rock bass
biomass declined by 50% compared to the 1990 survey (from 38.1% to 19.0%).
We have no explanation for this. The perch population remained quite stable
from 1975 to 1992.
A. Current management.
In general, Thousand Island Lake still has a nice fish community and
should continue to provide decent angling opportunities. However, if future
surveys show the predator biomass continuing to decline, fingerling walleye
stocking should be again undertaken. The walleye, the primary predator,
should be closely watched to assure their population is reproducing and
is well-balanced. If walleye abundance goes lower, the fish community
of the entire lake will be adversely effected. Surveys should be conducted
at least every 3 years.
B. Goals and expectations.
The management goal for Thousand Island Lake is the same as for the entire
Cisco Chain, namely to maintain well-balanced and diverse species complexes
in these lakes to provide good fishing for all user groups. To accomplish
that goal, it may be necessary to stock fish (notably walleye) and to
periodically manipulate the populations of species which may become overabundant
or stunt (bluegill, perch, rock bass, etc.). Specific goals include:
1.Maintain the predator biomass at 30% or higher to provide an attractive
sport fishery and control undesirable species while maintaining a balanced
panfish community. Predators include northern pike, smallmouth bass, and
2.Maintain high average size of panfish. Minimum targets are 7.0 inches
for bluegill, 10.0 inches for black crappie, and 8.0 inches for yellow
3.Determine if the walleye population is sustaining itself through natural
C. Obstacles to attainment of goals.
Keeping a healthy population of walleyes in this lake is essential to
maintaining the fish community in a well-balanced condition. If excessive
numbers of this predator are withdrawn from the lake, for whatever reason,
panfish species may become overabundant. Natural reproduction also appears
to have declined over the last several years. This may be due to normal
year-to-year variation but might be an indication of some other problem.
Report completed: February 5, 1993.
Table 1.-Number, weight and length indices of fish collected from
Thousand Island Lake with 3/4-inch fyke nets, May 29-31, 1990.
Table 2.-Number, weight and length indices of fish collected from
Thousand Island Lake with 3/4-inch fyke nets, June 16-18, 1992.
Table 3.-Average total length (inches) at age, and growth relative
to the state average, for three species of fish sampled from Thousand
Island Lake with 3/4-inch mesh fyke nets, May 29-31, 1990. Number of fish
aged is given in parentheses. All fish aged by spine analysis.
Table 4.-Estimated age frequency (percent) of three species of
fish caught from Thousand Island Lake with 3/4-inch mesh fyke net, May
Last Update: 08/05/02