UT's Energy, Environment
and Resources Center Presents
Smoky Mountain
Resource Issues in Great Smoky Mountains National Park
SIGHTLINE
FALL/WINTER 2002
Vol. 3 No. 2
***
Editor: David Brill; Assistant Editor: Constance Griffith; Writers: Kris Christen, Lisa Byerley Gary, Elise LeQuire, Dennis McCarthy, and Becky Nichols. Graphic Designer: Lisa Byerley Gary.
SIGHTLINE is published on behalf of
Great Smoky Mountains National
Park
by the
Energy, Environment and Resources
Center (EERC)
at the
University of Tennessee.
EERC conducts research designed to promote real-world solutions to problems in the fields of energy, environment, technology, and economic development.
For additional information, write EERC, 311 Conference Center Building, The University of Tennessee, Knoxville, TN 37996-4134, call 865-974-4251, or visit our Web site at http://eerc.ra.utk.edu.
SIGHTLINE is sponsored by:
and
Return Engagement
The
only salmonid native to the Smokies, the brook trout is being restored to
some of its historic range.
by Elise LeQuire
Like many species in the Southern Appalachians, the brook trout weathered the Pleistocene glaciation, as the saber-toothed tiger and woolly mastodon became extinct and humans began to dominate Earth. In the modern era, however, human pressures have reduced the historic range of Salvelinus fontinalis, a typically freshwater member of the Salmonidae family that includes salmon, true trout, and char such as brook trout.
As the only trout native to the region, the Southern Appalachian brook trout historically thrived in cool, clear streams from southwestern Virginia to northern Georgia at elevations between 1,700 and 4,500 feet. The brookies, also known as speckled trout by locals, prefer stream temperatures between 40 and 60 degrees Fahrenheit, but can briefly tolerate temperatures as cold as 32 or as warm as 77 degrees. Though they evolved to withstand the slightly more acidic conditions of upper-elevation streams, acid deposition from combustion of fossil fuels is altering stream chemistry. In addition, introduced rainbow and brown trout have displaced the brook trout in much of its natural range.
Stock Answers
A century ago, extensive logging and fires had destroyed much of the forest canopy that kept streams cool, which reduced the brookies’ original range by 50 percent. Afterward, the brook trout could be found only upstream of where logging activities had occurred. Stocking streams then with species such as rainbow trout native to the Sierra Nevada Mountains and the Western states and brown trout native to northern Europe seemed like a good idea. The introduced species, generally longer-lived than brook trout and growing to larger sizes, filled a niche in the warmer reaches of mountain streams.
The U.S. Fish and Wildlife Service was in charge of fisheries maintenance at that time, and the National Park Service (NPS) saw no harm in stocking streams within Great Smoky Mountains National Park (GSMNP). Surveys during the early 1980s, however, showed that an additional 50 percent of the range occupied exclusively by brook trout had been lost since the Park was established and logging ceased.
Today, an informed experiment is underway to restore the native, southern strain of S. fontinalis to some of its historic range within the Park. “This is a really complicated process,” says Steve Moore, supervisory fishery biologist with NPS. “In the past, a lot of opinions and decisions were based on emotions, not science. We are refining our work to provide managers with good information to guide the decision-making process.”
Choose Your Poison
A pilot project in Sams Creek, in the Middle Prong of the Little River watershed, is a case in point. Like many streams in GSMNP, Sams Creek is home to a remnant population of brook trout. Until summer 2001, the creek also harbored rainbow trout. The plan was to remove the rainbows and restore the brookies. To that end, Park biologists considered several strategies.
One option, electroshocking, has been used in the Park for over 20 years in small streams. Biologists temporarily stun all the fish in the treatment area. When the fish float to the top, the introduced species are removed from the stream and the brook trout returned to the stream. Although electroshocking has little effect on other aquatic species, it doesn’t remove 100 percent of the non-native trout and is extremely labor-intensive. The process must be repeated several times in a year to achieve even a 75-percent reduction in selected fish populations, in part because fish lurking under rocks and in deep pools may escape the shock and live to spawn again.
Another option was really no option: Biologists could leave the stream alone and see what nature would do. The problem here, says Moore, is that “the Park Service has a mandate to protect naturally functioning ecosystems.” Moore is referring to the NPS Organic Act of 1916 that calls for managers to preserve the Park’s natural and historic resources “unimpaired.”
Finally, they considered poisons, or piscicides, that are approved by the U.S. Environmental Protection Agency for use in reintroduction efforts; unfortunately, such poisons also kill other species, including aquatic insects such as mayflies and caddis flies, staples of the brook trout’s diet.
An assessment of two piscicides, antimycin—a class of antibiotic that blocks cellular respiration—and Rotenone, revealed that antimycin has fewer adverse impacts on species other than fish, is more effective in cooler water, and is easier to neutralize after treatment.
Some researchers voiced concern about a certain caddis fly, Neophylax kolodskii, discovered in 1987, that was new to taxonomists. If Sams Creek were the only habitat for this insect, NPS would abandon its plan to restore brook trout to the stream. In the past two years, however, an extensive search revealed that the insect, though hard to find, lives both inside and outside the treatment area and should repopulate the stream naturally.
The Park Service ultimately settled on a combination of electroshocking and poisoning. In the summer of 2001, Park biologists and volunteers electrofished Sams Creek, moved the brook trout upstream, and applied lethal doses of antimycin to about four kilometers, or two and a half miles, of the stream—at an elevation of 2,000 feet and upstream of a waterfall that would serve as a barrier to introduced trout.
Post-treatment monitoring of fish found no evidence of surviving rainbow trout. Moreover, the survival rate of aquatic insects was better than expected, indicating that antimycin is a safe chemical to use in reintroduction projects. “We found populations reduced by only 40 to 50 percent. And four months later, we found more aquatic insects in the creek than before,” Moore says, in part because there were no fish to eat them.
Dry Spell
A year after treatment, the brook trout are returning to Sams Creek, with a little human help. The hope was that brook trout would naturally migrate downstream to the treated area, but an extended three- to four-year drought eliminated half the fish population. “Brook trout haven’t moved down from headwaters as anticipated,” Moore says. “The fish that have moved down are the ones that spawned out last year, so the small ones get displaced first, but they don’t move much over half a mile.”
In July 2002, biologists collected 150 Southern Appalachian brook trout in the Little River watershed and carried them overland to Sams Creek. Although biologists prefer to let the brookies repopulate on their own, “we want to get the stream repopulated as fast as we can,” Moore says. “I want to let the resident fish do as much as possible, so repopulation will be a little bit slow.”
After collecting the brookies, biologists tested them to ensure that they are the true race of Southern Appalachian trout.
Hatchery stocks of brook trout descend from populations in the northeastern United States; there are no domesticated stocks of Southern Appalachian origin. “The northern strain is genetically different from the southern race,” says Peter Galbreath, director of the Mountain Aquaculture Research Center at Western Carolina University.
Galbreath has collaborated with the North Carolina Wildlife Resources Commission, the U.S. Forest Service, and Trout Unlimited over the past few years to determine the genetic origin of wild brook trout populations in North Carolina. “In cases where hatchery brook trout interbreed with native Southern Appalachian brook trout, a population of mixed genetic origin results, which is forever altered from the genetic nature of either the original native population or the hatchery stock,” Galbreath says.
The distinction between strains is not easily detectable to the human eye, though the Southern Appalachian strain may tend to have a relatively larger head. The difference, however, is not definitive, according to genetic research conducted on brook trout in the Park by Stanley Z. Guffey, a lecturer in the Division of Biology at the University of Tennessee. Some seasoned anglers claim to be able to tell the difference. In any event, the difference is obvious at the biochemical level by protein or DNA analysis. “We would not move fish if we weren’t certain of the genetic background,” Moore says.
Sams Creek is one of 11 streams in the Park where brook trout restoration projects are underway. So far, non-native trout have been removed and brookies restored in 10 to 11 miles of stream. “We have surveyed about 100 miles of stream and restored 10 percent of brook trout within its historic range,” Moore says.
Eventually, as the population rebounds, Sams Creek may be open for fishing. For now, it remains an experimental test site off-limits to anglers. However, in July 2002 the Park Service announced the reopening of eight GSMNP streams to brook trout fishing. (See “Gone (Electro)fishin’,” page 17.)
Threatening Skies
The restoration of the brook trout is just one phase of a long-term Park-wide effort to determine the range, health, and variation in natural populations of all aquatic wildlife. “We’re also looking at water chemistry, especially acid deposition, to see how that is affecting fish populations,” Moore says.
Though brook trout have evolved to withstand higher levels of acidity than other species, they do not thrive when pH drops below 5.6. Because some upper-elevation Southern Appalachian streams receive high levels of acid deposition, they become acidic enough to stress young fish and approach the lower limit for trout viability. In fact, while these reintroduction efforts are a positive step toward preserving the Southern Appalachian region’s only native trout, Park biologists maintain that continued acidification of mountain streams from fossil-fuel combustion will likely remain a greater threat than competition from introduced trout and the sport of angling.
For more information on the Park’s fisheries program, contact Bob Miller, Great Smoky Mountains National Park, 107 Park Headquarters Road, Gatlinburg, TN 37738, or call 865-436-1207.
* * *
Gone (Electro)fishin’
In the past several years, some avid anglers have laid down their fly rods and picked up electroshocking gear, nets, and buckets to help in brook trout restoration and monitoring projects in streams of the Smokies. In fact, thanks to information garnered through such efforts in streams inside and outside the borders of Great Smoky Mountains National Park, in July 2002 the National Park Service reopened eight streams to anglers on an experimental basis.
For more than 25 years, fishing for brookies in the Park was banned out of concern for preserving the stock of this native trout. Fortunately for fishers, and for brook trout, studies have shown that brook trout populations in streams open to angling outside the Park are equivalent to populations in streams in the Park where fishing for brookies had been banned.
Now, a Park Service pilot project is allowing fishing in four streams on the North Carolina side of the Park and four on the Tennessee side. Over the next three years, eight similar streams in the same watersheds will remain closed to fishing so that fishery biologists can compare the populations of the two groups.
If the study confirms that brook trout can thrive under fishing pressure, the Park Service plans to open more streams to anglers in the future. For now, the ban on fishing in all other currently closed streams remains in effect. The Park Service has posted signs to help anglers identify which streams are open to fishing and updated its fishing regulations to show the locations of the newly opened streams. All other Park regulations—including the seven-inch minimum size—remain in effect, and anglers must carry a valid fishing license from North Carolina or Tennessee and observe state and Park regulations.
With its resources stretched to the limits, the Park Service has relied on volunteers from organizations such as Trout Unlimited, the Student Conservation Association, the National Fish and Wildlife Federation, Friends of Great Smoky Mountains National Park, Tennessee Brookies, the Federation of Fly Fishers, the University of Tennessee, and the wildlife resources agencies of Tennessee and North Carolina to provide manpower and financial support for its monitoring and reintroduction projects.
In a monitoring/electrofishing expedition, researchers and volunteers fan out across a stream, apply a low-voltage electrical charge with a wand attached to a motorized backpack, net the stunned fish, put them in buckets, carry the buckets back to the base of operations, sort the fish according to species, measure their length, weigh them, and return them to the stream. It’s a labor-intensive undertaking.
“Trout Unlimited has done an absolutely fantastic job of supporting all this work on the local, regional and national levels,” says Steve Moore, supervisory fishery biologist with the Park Service. “For all our projects, from restoration to stream chemistry monitoring to electroshocking, volunteers from these organizations donate 2,000 to 4,000 hours of labor each year.”
“We’ve been helping with the stream monitoring projects for 10 years,” says Tom Eustis, president of the Little River Chapter of Trout Unlimited. “We do a little bit of everything in terms of supplying folks to help in the population studies, moving the trout from other locations, and reintroducing them to Sams Creek. We also participated in the cleanout when the Park Service removed the rainbow trout from Sams Creek.”
On the Tennessee side of the Park, streams open to fishing for brook trout include Cosby Creek and Indian Camp Creek within the Park, Walker Prong upstream of Road Prong, and Fish Camp Prong upstream of Goshen Prong. In North Carolina, the streams are Beech Flats Creek above Kephart Branch confluence, all of Bunches Creek within the Park, Hazel Creek upstream of Proctor Creek, and Lost Bottom Creek upstream of Palmer Creek.
—Elise LeQuire
More information on Park fishing regulations is available at Park visitor centers.