Montana's Fish Species of Special Concern
Blue Sucker
Montana Fish Wildlife and Parks
Lewistown, MT
59457
June 1998
Status
In 1989 the American Fisheries Society added the blue sucker (Cycleptus
elongatus) to its list of rare North American fishes rated as Special
Concern (Williams et al. 1989). In
1994 the blue sucker was listed by the U. S. Fish and Wildlife Service as a
Category 2 species. In
1996, it was
upgraded by the State of Montana as a species of special concern Class C to
Class B (Chris Hunter 1987). Montana
populations appear to be stable and fairly abundant with a healthy size
structure. Although the blue sucker
populations appear to be healthy and stable, special recognition is warranted
because this species may be susceptible to population declines due to its unique
biological characteristics (longevity, low recruitment, migratory nature
and reliance on high flows in tributary streams for spawning).
Montana has some of the finest habitat for blue suckers found in their
range and losses of the Montana populations would be significant to the overall
gene pool.
Distribution
The
blue sucker has a widespread distribution extending throughout the Mississippi,
Missouri, Ohio, and portions of the Rio Grande river systems (Elstad and Werdon
1993). In
Montana, it is found in
the Missouri as far upriver as Morony Dam near Great Falls, and in the
Yellowstone upriver of Forsyth, MT (Figure 1).
Blue suckers have been found in many of the major tributary streams
during their spawning season. There
have been very few blue sucker
sampled in Fort Peck Reservoir indicating their avoidance of lake environments.
Figure 1. Distribution of
blue sucker in Montana 1990-97.
Life history/Ecology
The
blue sucker is adapted for life in swift current areas.
This fish prefers swift current areas of large rivers, feeding on insects
in cobble areas (Moss et al. 1983). In
the spring blue suckers migrate upriver and congregate in fast rocky areas to
spawn. Large numbers have
been
observed migrating up tributary streams to spawn.
The Tongue, Marias, Milk and Teton rivers are the tributary streams most
heavily used. Blue suckers can live
longer than 17 years. Berg (1981)
reported that 93% of sampled fish in the upper Missouri were 9-14 years old.
Reproductive
success may be a problem for this habitat-specific species.
Very few young-of-year (YOY) blue suckers have been collected while
sampling with a variety of methods. Moreover,
the populations are dominated by older fish indicative of minimal recruitment.
Blue sucker larvae have been collected from the Milk River, Big Muddy
Creek,
and in the lower Missouri and Yellowstone rivers (Gardner and Stewart
1987, Penkal 1981). Additionally,
young-of-the-year blue suckers have been sampled at the Milk River confluence
and in Big Muddy Creek of the lower Missouri River (Liebelt 1996 and Stewart
1980).
Blue
sucker data records are sparse since most information collected on blue suckers
is by-catch data collected in the course of targeting other species.
Moreover, because of the blue suckers preference for main channel swift
water habitats, they are difficult to sample and consequently have not been
sampled in large numbers. Blue
sucker sampled in Montana are typically older and large fish with lengths of 60
to 75 centimeters and 3-5 kilograms.
In
Montana, the most informative data available about blue suckers is length
distribution data for the three river reaches where this species is found.
The upper Missouri and lower Yellowstone populations have similar size
structures with dominant size classes of 65 and 70 cm (Figure 2).
The lower Missouri population size classes are generally smaller (Figure
2).
To
evaluate changes in the populations over the past 10-20 years, length
distribution information was compared with past records for the upper and lower
Missouri River populations (Figure 2). The
size structure of the upper Missouri population was similar for a
span of 16
years. However, for the lower
Missouri population the 1993-94 sample had a more balanced and desirable size
structure with a wider length distribution and better representation of smaller
size classes than found in the 1983 sample. The blue sucker appears to be somewhat common in the Missouri
and Yellowstone rivers. During
1994, FWP sampled over 300 while attempting to capture pallid sturgeon in the
Yellowstone River (Backes et al. 1994). The
blue sucker is monogeneric and is not known to hybridize with any other species.
Threats
Present
information describes the species as widespread throughout the USA and in
Montana. There are no known blue
sucker populations that have been extirpated.
However, where extensive riverine losses have occurred due to
impoundments, there have been major population losses and blue sucker
populations have been fragmented. In
Montana, the blue sucker is present in most places that have available habitat.
The lower Yellowstone River blue sucker population would probably exist
farther upriver if the Cartersville Diversion Dam and other diversion dams on
the Yellowstone did not restrict upriver
passage.
Figure
2. Length-frequency distribution
for blue sucker populations sampled by electrofishing and drift netting in the
upper and lower Missouri and lower Yellowstone rivers, Montana.
Management
Management of the blue sucker consists mainly of routine monitoring of
the population status and habitat protection.
The blue sucker is considered an indicator species for ecosystem health
because of its habitat-specific requirements.
Current monitoring information indicates the populations are in stable
condition. Efforts towards locating
spawning and rearing areas should be continued.
Habitat protection includes protecting or promoting the natural
spring-time hydrograph. Establishment
of more natural seasonal flow conditions are presently being discussed and
initiated for three storage reservoirs in Montana.
Literature Cited
Backes,
K. M., W. M.Gardner, D. Scarnecchia, and P. A. Stewart. 1994.
Lower Yellowstone River Pallid Sturgeon Study III and Missouri River
Pallid Sturgeon Creel Survey. MT
Fish Wildlife and Parks. Miles
City. 18p.
Berg,
R. K. 1981. Fish Populations of the Wild and Scenic Missouri River, Montana.
Montana Fish Wildlife and Parks.
Gardner,
W. M. and P. A. Stewart. 1987. The
Fishery of the Lower Missouri River, Montana.
Montana Fish Wildlife and Parks. Helena.
224p.
Gardner, W.M. 1997. Middle
Missouri River fisheries evaluations. Mont.
Dept. of Fish Wildlife and Parks. Helena.
Fed. Aid to Fish and Wildlf. Rest. Proj.
F-78-R-3. 34 p.
Liebelt,
J. 1996. Lower Missouri River and Yellowstone River pallid sturgeon
study. 1994-95 Report. MT
Fish Wildlife and Parks. Fort Peck.
57p.
Hunter, Chris. 1997. Montana Outdoors. November/December. MT Fish Wildlife and Parks. Helena, MT.
Moss,
R. E., J. W. Scanlan, and C. S. Anderson. 1983.
Observations on the natural history of the blue sucker (Cycleptus
elongatus LeSueur) in the Neosho River.
The American Midland Naturalist 109(1):15-22.
Penkal,
R.F. 1981. Life history and flow requirements of paddlefish, shovelnose
sturgeon, channel catfish and other fish in the lower Yellowstone River system.
Montana Fish, Wildlife & Parks.
Helena
Stewart,
P. A. 1980. Lower Missouri River
Basin investigations, planning inventory, fisheries. Federal Aid Fish and
Wildlife Restoration. Project No. FW-2-R-9 Job Ib. Montana Fish Wildlife and
Parks.
Elstad,
S. A. and S. J. Werdon. 1993.
Draft status report on Blue Sucker (Cycleptus
elongatus), a candidate endangered or threatened species.
U.S.Fish and Wildlife Service. Bismarck, ND.
Williams,
J. E., J. E. Johnson, D. A. Hendrickson, S. Contreras-Balderas, J. D. Williams,
M. Navarro-Mendoza, D. E. McAllister, and J. E. Deacon. 1989.
Fishes of North America endangered, threatened, or of special concern:
1989. Fisheries (Bethesda) 14(6):2-20.
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