Conservation Fisheries, Inc.
Newsletter #4
February 1, 2001
Abrams Creek Recovery: a 15-year Update
It's hard to believe, but it's been almost 15 years
since recovery efforts began in the Great Smoky Mountains
National Park to restore rare fishes eliminated from Abrams
Creek. These extirpations
were the result of a "stream reclamation" project in the
1950âs aimed at improving fishing for the introduced rainbow
trout.
This project is the first of
its kind in the southeastern U.S., using all captively propagated
fishes to restore populations to their historic waters. CFI has
been involved in this landmark project from the beginning,
supplying and restocking fishes, and monitoring the progress of
the project. The species to be restored were: the spotfin chub, Cyprinella
monacha (federally threatened); the Smoky madtom, Noturus
baileyi (federally endangered); the yellowfin madtom, N.
flavipinnis (federally threatened); and the duskytail darter,
Etheostoma percnurum (federally endangered).
The restoration of these fishes to Abrams Creek was the brainchild of Dr. David Etnier of the University of Tennessee (UT) along with the U.S Fish and Wildlife Service (USFWS) and the Tennessee Wildlife Resources Agency (TWRA). The Park turned out to be the ideal testing ground for an undertaking such as this for several reasons. Abrams Creek is in relatively good condition (the catastrophic loss of these species from the stream was the result of a one-time event) and contains habitat suitable for the species listed above. The majority of the watershed is located on public lands, so potential problems related to private land ownership are not a factor. But, probably the most important factor was that viable populations of three of the four species being considered for reintroductions had recently been discovered in nearby Citico Creek. The fourth species, the spotfin chub, is still relatively abundant in the upper Little Tennessee River to which both Citico and Abrams Creeks are tributaries. It was realized early in our project that the madtoms and darter did not occur anywhere in numbers sufficient to be translocated into Abrams Creek. Therefore, captive propagation seemed the best solution.
For the first several years
our operation was small, funding was limited and the numbers of
fish produced and stocked were low. For the first five years or
so, we rarely saw any of the fish we were stocking once they went
into the waters of the creek. The initial project was aimed at
restoring the two madtoms. In 1993, the first captively
propagated duskytail darters were stocked into Abrams Creek.
Spotfin chub reintroduction had been attempted in 1988 when the
USFWS, TWRA, UT, North Carolina Wildlife Resources Commission
(NCWRC), the National Park Service (NPS) and others moved several
hundred individuals from the Little Tennessee River in North
Carolina. These efforts apparently were not successful. In 1998,
the first serious efforts to stock captively produced spotfin
chubs into Abrams Creek began.
To date, we have stocked more
than a thousand yellowfin madtoms, more than twenty-five hundred
Smoky madtoms, more than seventeen hundred duskytail darters and
nearly ten thousand spotfin chubs into Abrams Creek! While this
sounds like quite a few fish, these have been spread out over the
years (fifteen for the madtoms!) and over a relatively broad
stocking area, around five stream miles.
So, where do we stand now? In
the past five years we have seen regular nesting and good
juvenile recruitment of Smoky madtoms and duskytail darters! Both
of these species are expanding into areas of the stream where
suitable habitat exists. In the spring, we can find nests of both
of these species.
We have seen some
in-stream-spawned yellowfin madtoms, although theyâre not as
abundant as Smoky madtoms. We also see good numbers of adults
throughout the warmer months during nighttime snorkel surveys.
However, even in Citico Creek, where both Smoky and yellowfin
madtoms are found, yellowfins are far less abundant than Smoky
madtoms. At this time, we usually have no way of knowing whether
the adults we see in Abrams Creek were spawned in-stream, or at
our facility. Starting this year, we hope to mark many of the
fish we release. This will help us determine survivorship and
dispersal of the fish we're stocking.
The reintroduction of
propagated spotfin chubs into Abrams Creek has only been
going on for a couple of years now. For
the past few years, we have seen good numbers of young sub-adults
in the fall (after spring releases of juveniles). Growth has been
good and the fishes seem to disperse into most of the available,
suitable habitat. However, by the next spring, we were seeing
only a few of the fish stocked the previous year, and we were
seeing no indication that they were spawning in Abrams Creek.
This fall, however, we found several juvenile spotfin chubs in
Abrams Creek that had to have been spawned that summer by fishes
we had released the previous year. We were thrilled! For the
first time, we knew that all four of the species we were working
to recover were reproducing in Abrams Creek.
So, where are we going now?
What we have seen so far has been very encouraging! But the
restoration of these fishes is far from over. Our plans are to
continue to stock captively propagated fish (all four species)
into Abrams Creek. There are several reasons to continue stocking
these fish. Since a relatively few adults contribute offspring to
the overall stocked numbers, it is important to continue adding
new genetic stock to help insure the transfer of as much of the
genome as possible. Also, while several of the species seem
pretty well established in some areas of the stream, we want to
hasten their dispersal to other suitable areas in the stream.
And, obviously, at least the yellowfin madtom and spotfin chub
are far from secure in Abrams Creek at present.
We are now having some success
at CFI in the aquarium spawning of various madtom species. We
hope that within a couple of years, we will be able to produce
many more yellowfin madtoms for reintroduction. At this point,
wild nests are collected from Citico Creek and reared in our
facility for reintroduction purposes. Because the species is
rare, even in Citico Creek, we are limited to removing only a
couple of nests every year. Aquarium spawnings could contribute
many more individuals to the project.
In years past, we have stocked
spotfin chubs at a relatively small size, at a little less than
one year of age. We are now planning to stock spotfins at almost
two years of age. These will be sub-adults and should be capable
of spawning their first year in the stream. We are hoping this
will not only reduce potential predation, but by having the fish
ready to spawn the first year, they should be able to locate one
another more easily before significant dispersal takes place.
We also continue to monitor
the parent populations of the two madtoms and duskytail darter in
Citico Creek. With support from the U. S. Forest Service,
Cherokee National Forest (USFS) we annually monitor the health of
the Citico Creek populations. Currently, all three appear to be
doing well there.
The success of this project is
due largely to the personal dedication and long-term support of
many of the agency personnel involved. Because early indications
are that captive propagation and reintroduction is a feasible
method of restoring rare fish populations, other projects are
being considered for the near future. Captive propagation is a
valuable tool for fish restoration, but it is only a tool.
Without recovered streams to work with, restoration is
impossible! It is also not a quick fix. Projects such as this can
take many years to complete. This does, however, offer us options
when working with fishes too rare to translocate.