ENDANGERED BOULDER DARTER GETS A HABITAT BOOST
-- 15 TONS OF BOULDERS MAKE HABITAT FOR CAPTIVE-REARED FISH--
The endangered boulder darter today just got a little breathing and
spawning room from 15 tons of rocks and a successful partnership between
federal, state and private organizations and agencies.
The U.S. Fish and Wildlife Service, in conjunction with Tennessee
Wildlife Resources Agency (TWRA), Tennessee Valley Authority, and
Conservation Fisheries, Inc. (CFI), hand carried the rocks to two
locations
on the Elk River.
"This is not work for the faint of heart or back," said Lee
Barclay,
Supervisor of the U.S. Fish and Wildlife Service Cookeville Ecological
Services Office. "But it has a proven track record in creating the
best
habitat for the darter."
The partners created the special habitat needed by the darter with
a
large dump truck load of rocks from Noland Stone Company, Nashville,
Tennessee. After being dropped at the riverbank near Hamilton Mill, at
Dellrose, Tennessee, biologists, scientists and conservationists
hand-carried the 15 tons of boulders into the Elk River. Then the 200
captive-reared endangered boulder darters were given their first taste
of
freedom in the Elk River.
"Since the boulder darter is one of the rarest fish in the United
States, we have to go above and beyond to help it recover," said Gary
Myers, Executive Director of TWRA. "This is a great way to help reclaim
a
species on the brink."
The endangered boulder darter (Etheostoma wapiti) is a small-sized
member of the perch family reaching a maximum length of about three
inches.
The males of the species are olive to gray in color, while the females
are
similar but lighter in color. Both sexes have a gray to black bar
located
below the eyes and a similarly colored spot behind the eyes. The
boulder
darter is currently found only in the Elk River, a large tributary
system
of the Tennessee River in southern Tennessee and northern Alabama. It
is
currently restricted to about 63 miles (101 kilometers) of the main
channel
of the lower Elk River and a few of its tributaries.
The species is not distributed continuously within this range,
but
is concentrated at a few sites with suitable habitat. Historically, the
boulder darter also lived in Shoal Creek, a tributary of the Tennessee
River in northern Alabama, but that population has been extirpated.
As the common name suggests, the boulder darter lives and spawns in
mid-June to late summer among boulders that occur in relatively shallow
water, in depths of three feet or less. The boulders must also occur in
flowing water that is not too swift, such as in riffles or rapids, and
not
too slow, as in slightly flowing pools. These conditions are ideal for
maturation of the eggs that are attached to the undersides of these
rocks
and guarded by the male. Because of this specificity, suitable habitat
is
limited.
In addition to this lack of habitat, many human-caused factors have
contributed to the decline of the boulder darter. In the Elk River, the
major impacts resulted from impoundment of the upper river section by
Tims
Ford Reservoir; thermal alteration of the tailwaters below Tims Ford Dam
from warm to cold water; impoundment of the lower Elk River by Wheeler
Reservoir; fluctuating water levels from power generation at Tims Ford
Reservoir; industrial, municipal, and agricultural pollution; and
extensive
siltation from soil erosion. The primary reasons for the demise of the
boulder darter in Shoal Creek were the impoundment of the lower creek by
Wilson Reservoir, siltation from agricultural erosion, and pollution
from
upstream municipalities in Alabama.
As a result of these threats and the species' limited range, the
U.S.
Fish and Wildlife Service listed the boulder darter as an endangered
species in September 1988. The Service, along with other conservation
agencies and organizations, has been working ever since to learn more
about
the boulder darter and its habitat. This information is being used to
protect and restore the species to its historic range.
In 1995, CFI, a non-profit organization in the business of
propagating
rare fish species, collected boulder darters from the Elk River to
develop
a captive breeding program. This was initiated in the hopes that
population numbers in the Elk River could be augmented and the fish
possibly reintroduced into Shoal Creek.
"Boulder darters were once so rare that we were forced to work with
bloodfin darters, a closely-related, common species to learn more about
boulder darter habits and spawning," said Pat Rakes of CFI. "In 1995 or
1996, we were able to collect a whopping number of four boulder darters
from which we eventually reared 200 individuals."
In addition to these efforts, personnel with CFI have surveyed the
Elk
River looking for additional occurrences of boulder darters and suitable
habitat where captive-reared fish can be released. They have also
surveyed
Shoal Creek for suitable habitat for possible locations of future
reintroductions of the species.
At about the same time, personnel with TWRA began augmenting
existing
spawning habitat with man-made, concrete structures fashioned to mimic
natural slabrock. Because these structures met with limited utilization
by
boulder darters, TWRA, the Service, and CFI decided to try utilizing
natural limestone slabrock. In the summer of 1999, three-and-a-half
tons
of slabrock were placed in the Elk River at a known boulder darter
occurrence. Subsequent surveys of the site revealed the largest
concentration of boulder darters ever found. As a result of this great
success, efforts to augment spawning habitat at other locations in the
Elk
River continue with boulder placement and reintroductions at two sites
in
August 2001 at Hamilton Mill and Fayetteville, Tennessee.
Through the partnerships of agencies and entities and the
successful
implementation of various recovery efforts, it is hoped that these
successes will enable the U.S. Fish and Wildlife Service to someday
remove
this species from the list of endangered species.
For photos and more information, visit: http://southeast.fws.gov
The U.S. Fish and Wildlife Service is the principal federal agency
responsible for conserving, protecting and enhancing fish, wildlife and
plants and their habitats for the continuing benefit of the American
people. The Service manages the 94-million-acre National Wildlife Refuge
System that encompasses more than 535 national wildlife refuges,
thousands
of small wetlands and other special management areas. It also operates
70
national fish hatcheries, 64 fishery resource offices and 78 ecological
services field stations. The agency enforces federal wildlife laws,
administers the Endangered Species Act, manages migratory bird
populations,
restores nationally significant fisheries, conserves and restores
wildlife
habitat such as wetlands, and helps foreign governments with their
conservation efforts. It also oversees the Federal Aid program that
distributes hundreds of millions of dollars in excise taxes on fishing
and
hunting equipment to state fish and wildlife agencies.
Nick Zarlinga
Aquarium Biologist
Cleveland Metroparks Zoo
216-661-6500 ex 4485
"Fish worship... is it wrong??" (Ray Troll)
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