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lake restoration from the website..

Putting Back the Pisces


by Konrad Schmidt


The Knife River meanders about 25 miles through small farms and woodlands
in Mille Lacs and Kanabec Counties before joining the Snake River near
Mora (See map). The first permanent dam on the river was constructed in
1929 about six miles above the mouth which formed an 1100 acre reservoir
now known as Knife Lake. In 1972, a sixteen inch rain fall and resulting
flood breached the county road adjoining the dam which had also served as
a barrier preventing carp from entering the lake. A temporary dam was
completed in the same summer, but carp could still get over this obstacle
whenever the river flooded.

I began visiting the area about the same time to fish and hunt with a
friend who had a cabin on Knife Lake. I really enjoyed those weekends and
was always amazed how this special place could be overlooked barely an
hour from the Twin Cities. However, pursuits wax and wane, and mine
"evolved" into a highly specialized interest in nongame fishes which
brought me back years later for an entirely different purpose. 

In 1988, I heard about the Knife Lake Rehabilitation Project. These
projects are proposed for lakes where rough fish, usually carp and
bullheads, have become the most abundant species in the fish community. A
fish toxicant called rotenone is ap- plied to remove these species.
Rotenone is derived from the bark of a tropical tree found in South
America where native peoples for centuries have used it to catch and
safely eat fish. Unfor- tunately this chemical is toxic to all species of
fish. I was confident that the game fish community in Knife Lake would be
reestablished through DNR stocking programs. However, this project
included the treatment of all streams in the watershed above the lake.
Streams generally contain not only more types of habitats than lakes, but
also possess richer, much more diverse fish communities which are
dominated with nongame species. Most are less than five inches long and
are much more abundant than game fish in both species and numbers. In
this melting pot, there are hunters like the stonecat which stalk riffles
in search of aquatic bugs and vegetarians like the central stoneroller
which grazes on algae. Some are grotesquely armored like the brook
stickleback which erects spines for battle as potential predators
approach. And finally, some are gorgeous gems like the male northern
redbelly dace who struts about in courting colors of scarlet red and
lemon yellow. These are only a few examples of the nongame community
which I was far less certain would be naturally reestablished because the
completion of a new dam to impound Knife Lake once again functioned as a
total fish barrier. 

At this same time, I was volunteering for Minnesota State Parks
conducting fish surveys and pooling these results with historical records
to develop a species list for each park. It seemed like a natural move to
expand my project to include the Upper Knife Lake watershed. This also
gave me the opportunity to visit my friend's cabin on Knife Lake which
disappointingly no longer held the same appeal. The water was a vivid pea
green and I could not believe that I use to swim in this once dark but
always clear lake. My friends were even more disappointed by the poor
fishing and spent most of their time on other area lakes. 

My surveys began in April 1989 and continued through the rotenone
treatment in October. The last survey was the most bizarre I have ever
conducted and had looked forward to it with mixed feelings. Rotenone is
probably the most effective way to survey a fish community and I was
optimistic that new species would be found that have never been reported
before from the watershed. However, this was the first time I had ever
witnessed an intentionally induced fish kill and was not prepared for the
magnitude. At least I could say that on this rare occasion I felt not
even a twinge of guilt preserving specimens for a museum fish collection.
I did find a new species which was unexpected because it was not a fish,
but a very unique amphibian called the mudpuppy which resembles a
salamander, but never loses its gills. I had also hoped someone would
turn in a rare lake sturgeon which a few anglers had reported catching in
Knife Lake through the 1970s and I seined one, barely six inches long,
below the tempo- rary dam in 1974, but never did hear even a rumor of a
sighting. I also encountered more people on the river than I had seen in
the previous six months. Most were from the area and had incred- ible
childhood tales of trophy northern pike and smallmouth bass which had not
been caught in the river for decades and they all hoped these desperate
measures would some day bring that back. 

I compiled a final species list of 45 fishes for the Knife River Lake
Watershed from my results and DNR surveys going back to 1963. I believed
the best chance to successfully restore the historically native nongame
portion of this community would be early reintroductions conducted at the
same time game fish were being stocked. I contacted the DNR regional
fisheries office in Brainerd where I met Tim Brastrup who informed me the
intent was to eventually replace as many species as possible and he also
favored the early rather than later approach. That was enough to make
plans for the following year. I met Tim in Mora before sunrise one spring
day and to my surprise he brought a fish transport truck with all the
bells and whistles. I was very impressed! We agreed to collect fish only
from the Snake River watershed which would likely be similar genetically
to what had been present in the Knife Lake watershed. After a very long
day we released a smorgasbord of about 1500 "pioneers" - not too bad for
the first time. Tim made several more collecting trips with me, but the
transport truck was diverted for its primary purpose - stocking walleyes.
We resorted to trash cans which needed bungi cords to hold the lids down
as our ark "sloshed" up and down the country roads. I always wondered
what people thought as they would drive by watching us haul "garbage"
down to the stream. As primitive as it was, these early efforts were very
successful. Stream surveys conducted by the DNR and myself in the first
three years found the nongame community growing rapidly in both species
and abundance. As of the fall of 1993, thirty fishes had been found in
the Upper Knife River. Now our efforts are focused on species which are
still absent. This does include a few which we unfortunately still refer
to as rough fish. Perceptions are slow to change, but many of these
fishes are actually indicators of excellent water quality and habitat.
Although rarely appreciated, they are also tenacious fighters when
hooked, and believe it or not, make a delicious meal. This includes the
silver, golden, and shorthead redhorse, and the northern hog sucker. All
are native to Minnesota and were a small, but integral part of the Knife
Lake watershed community. The Hinckley Area Fisheries office released
silver redhorse during the spring of 1993 and there were plans to
continue with their cousins in 1994. I spend my time on the "little odds
and ends" such as madtoms, minnows, and mudpuppies. However, as the list
gets smaller, the remaining items get much harder to find. More than
once, very much welcomed assistance has come from the local conservation
officer, Paul Hoppe, who consistently points me to the right stream. With
his most recent tip, I probably stocked enough tadpole madtoms (a small
catfish) to take hold, but it was a painful process. They really don't
get "mad" - they just sting like a bee! I have also managed to round-up
about 150 mudpuppies which pose yet another occupational hazard to this
fish squeezer-their body slime bonds to human skin like super glue!

We've still got a ways to go and realistically the entire community can
never be fully restored, but at least it will almost mirror what was. 

I have revised the species list to reflect surveys con- ducted through
1996. This also indicates fishes which have not been reestablished (Table

Table 1. Knife Lake watershed fish species list before (1964-89) and
after (1990-96) reclamation. Compiled from my sampling results and
Minnesota DNR fish surveys. Plus (+) indicates presence and minus (-) not
sampled during the survey period. Common Name (scientific name) Before 
chestnut lamprey (Ichthyomyzon castaneus) + - 
bowfin (Amia calva) + - 
central stoneroller (Campostoma anomalum) + + 
largescale stoneroller (Campostoma oligolepis) - + 
common carp (Cyprinus carpio) + - 
brassy minnow (Hybognathus hankinsoni) + + 
common shiner (Luxilus cornutus) + + 
pearl dace (Margariscus margarita) + + 
hornyhead chub (Nocomis biguttatus) + + 
golden shiner (Notemigonus crysoleucas) + + 
emerald shiner (Notropis atherinoides) + - 
blacknose shiner (Notropis heterolepis) - + 
spottail shiner (Notropis hudsonius) + - 
northern redbelly dace (Phoxinus eos) + + 
finescale dace (Phoxinus neogaeus) + + 
bluntnose minnow (Pimephales notatus) + + 
fathead minnow (Pimephales promelas) + + 
blacknose dace (Rhinichthys atratulus) + + 
longnose dace (Rhinichthys cataractae) + + 
creek chub (Semotilus atromaculatus) + + 
white sucker (Catostomus commersoni) + + 
northern hog sucker (Hypentelium nigricans) + + 
silver redhorse (Moxostoma anisurum) + - 
golden redhorse (Moxostoma erythrurum) + + 
shorthead redhorse (Moxostoma macrolepidotum) + + 
black bullhead (Ameiurus melas) + + 
yellow bullhead (Ameiurus natalis) + - 
brown bullhead (Ameiurus nebulosus) + - 
channel catfish (Ictalurus punctatus) + + 
stonecat (Noturus flavus) + - 
tadpole madtom (Noturus gyrinus) + - 
northern pike (Esox lucius) + + 
central mudminnow (Umbra limi) + + 
burbot (Lota lota) - + 
banded killifish (Fundulus diaphanus) + + 
brook stickleback (Culaea inconstans) + + 
rock bass (Ambloplites rupestris) + + 
green sunfish (Lepomis cyanellus) - + 
pumpkinseed (Lepomis gibbosus) + - 
bluegill (Lepomis macrochirus) + + 
smallmouth bass (Micropterus dolomieu) + + 
largemouth bass (Micropterus salmoides) + + 
white crappie (Pomoxis annularis) + + 
black crappie (Pomoxis nigromaculatus) + + 
Iowa darter (Etheostoma exile) - + 
johnny darter (Etheostoma nigrum) + + 
yellow perch (Perca flavescens) + + 
logperch (Percina caprodes) + + 
slenderhead darter (Percina phoxocephala) - + 
walleye (Stizostedion vitreum) + + 
freshwater drum (Aplodinotus grunniens) + - 
Species Totals: 45 38 
mudpuppy (Necturus maculosus) + - 

Ideally, I would still like to see 10 more historically native fishes
plus the mudpuppy reestablished. I have released over 300 tadpole madtoms
and believed this would be sufficient, but none have been sampled in
follow up surveys. The stonecat has never been collected in sufficient
numbers. Hind sight is 20/20, but I now wish I had lobbied the DNR to use
Antimycin B instead of rotenone. This would not have affected the
catfish, but fisheries managers hoped the rotenone would also eliminate
the black bullheads, which not surprisingly, survived the holo- caust. I
have unsuccessfully tried to survey mudpuppies using traps which have
worked very well elsewhere. However, one land- owner was certain he saw
them under a county road bridge along his property in 1995. The DNR
Fisheries office in Hinckley has done one stocking of adult golden and
shorthead redhorse. Young of the year of both species were sampled in one
follow up survey along with northern hog suckers. In the spring of 1996,
I care- fully and diplomatically requested at least one more redhorse
stocking effort be made for good measure. After some delibera- tion,
fisheries agreed to provide a transport truck and Jack Enblom with the
Ecological Services would use a boom shocking boat to collect redhorse
and northern hog suckers in the Snake River. However, nature had another
agenda and heavy spring floods persisted far beyond the sucker's spawning
run. Everyone involved agreed it was best to wait another year. 


Robert Rice
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