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lake restoration (fwd)

J. L. Wiegert
 Dubotchugh yIpummoH.                      bI'IQchugh Yivang!
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---------- Forwarded message ----------
Date: Sun, 18 Oct 1998 12:13:24 EDT
From: Ellasoma at aol_com
To: nfc at actwin_com,
    robertrice at juno_com
Subject: lake restoration

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 1).

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  After 
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.