The Trout’s World
The rays of the early morning sun bombard the tops of the trees spread above the headwaters of Forney Creek. Some penetrate the canopy to make light patches in the lower layers of the forest. But few break through the rhododendron thickets along the stream to illuminate its mossy rocks, its foam, and its clear pools. Down in the darkness beneath overhanging shrubs, hanging in the current near the bottom of a pool, a brook trout waits for the stream to bring it food. With dark mottling along its back, red spots on its olive sides, and pale orange edging on its lower fins, the fish is beautiful. It is also small, about 18 centimeters (7 inches) long, and lean, for it lives in a harsh environment where food is scarce, the water is cold and acidic, and floods and thick ice can scour. This is one of only a few trout in the pool because there is not enough food for many.
The trout fed little during the night and now its hunger is acute. Carefully it watches the rippling surface for insects, spiders, crayfish, salamanders, and worms, or any animal life caught and carried down by the current. But nothing appears. It noses up to a rock where earlier in the summer it had found caddisfly larvae fastened in their tubular little cases made of tiny pebbles. Now none are left on the surface of the rock accessible to the trout. It searches other rocks and eventually finds one caddisfly larva and a small mayfly nymph, flattened against the under side. The trout dashes at a small salamander, which escapes under another rock. Three crayfish also inhabit the pool but they are too big for this particular trout to eat.
The trout’s hunger increases and still nothing edible washes over the miniature waterfall at the head of the pool. But suddenly sand and gravel begin dropping in and there is a pulsing in the flow of water. Upstream a bear has crossed and in its crossing it has knocked a beetle off an overhanging branch. The beetle floats down one little cataract after another, its legs kicking wildly and its wet wings vainly buzzing. There is a splash as the trout strikes. The beetle will sustain it through one more day.
In contrast to the brook trout’s life in the headwaters, the rainbow trout would appear to have an easier time in the lower reaches of park streams. Here the pools are larger, the stream gradient is less, the water is less acidic, and nutrients are more abundant. These conditions allow more plant and animal life to exist, and therefore create more food for trout. Also, at these lower elevations, where the water is deeper, winter ice cannot form so solidly as higher up. These waters are not exactly teeming with aquatic life, but they are adequate for rainbow trout.
Trout do not generally remain active continuously. They tend to feed in the late afternoon, at night, and early in the morning, resting at the bottom of a pool during midday. Both brook and rainbow trout will have resting sites, day and night, and feeding sites.
A favored feeding site is often the head of the pool, where a trout will have the first chance to seize insects or other organisms carried into the pool. It also has the option of hunting many of the forms of life that live in the stream with it: insect larvae and nymphs of many kinds, aquatic beetles and spiders, crayfish, leeches and worms, water-mites, snails, salamanders, tadpoles, and the smaller fish.
Among the more common fishes that live in rainbow trout territory in low elevation, low gradient streams are sculpins, dace, hogsuckers, river chubs, shiners, and stonerollers. Hogsuckers, which reach 30 centimeters (a foot) or more in length, can be seen in many large, quiet pools. There they search for food on the bottom with their downward protruding lips. Dace and shiners, members of the minnow family, are very small fish and some species are brilliantly colored. The river chub and stoneroller, also minnows, are larger; the stoneroller occasionally reaches 28 centimeters (11 inches). Locally known as “hornyhead” and enjoyed as a food fish, the abundant stoneroller may limit the numbers of rainbow trout in some stretches of stream because of its own spawning activities. Rainbows lay their eggs on gravelly areas in early spring. A month or so later, before the trout eggs have hatched, stonerollers frequently build their nests in the same places, covering or scattering the trout eggs in the process. This sort of competition was probably not expected or considered when rainbows were introduced to the Smokies; nevertheless, the trout do manage to perpetuate themselves.
No doubt the most peculiar creature in the lower sections of park streams is the hellbender, a huge, grayish salamander with a loose fold of skin along each side. Commonly reaching 30 centimeters (a foot) and occasionally more than 60 centimeters (2 feet) in length, hellbenders hide under rocks and debris in swift water and feed on fish and other animals up to the size of crayfish. Below elevations of about 500 meters (1,600 feet) smallmouth bass, rock bass, and brightly colored little darters appear in park waters. Brown trout, an introduced species that has apparently entered the park from farther downstream, live in the lower sections of some streams, and may be found in the headwaters of some streams. Of the three species of trout in the Smokies, browns generally prove most difficult to catch.
Since early in this century when rainbow trout were introduced, and possibly even before, brook trout have been retreating upstream in these mountains. In the late 19th century, brook trout occurred as low as 500 meters (1,600 feet); now they are found mostly above 915 meters (3,000 feet). The effects of logging and competition from rainbows are the most frequently suggested reasons for this retreat. Logging, which began on a large scale in the Smokies about 1900, brought with it many fires. The resulting exposure to full sunlight caused the warming of low-elevation sections of streams. Erosion of the denuded land added heavy loads of sediment to the streams. These changed conditions, and possibly heavy fishing pressure, apparently speeded the disappearance of brook trout from the lower elevations. Rainbows were introduced and proved able to survive. In the ’20s and ’30s it was noted that rainbows occurred in streams up to about the upper limit of logging, and that brook trout occupied streams above that point. Now, however, streams are once again shaded by forests their full length; but brook trout, instead of moving back down, seem to have retreated higher upstream. It appears that the larger, more aggressive rainbows somehow prevent brook trout from reoccupying their lost waters.
The National Park Service is concerned for the future of the Smokies’ one species of native trout, and especially for the few isolated populations of brookies that may still remain unmixed with populations of brook trout introduced from other parts of the country. On some streams, waterfalls provide effective barriers to the advance of rainbow trout, and use of artificial barriers for this purpose has been considered. Stringent fishing regulations may help the easily caught brook trout—and the gluttonous poaching that sometimes eliminates large numbers of brook trout from long stretches of a stream must be stopped. This type of management problem, how to preserve native species and reduce the impact of exotic ones, is common in national parks. It is only one aspect of a larger problem: How do we maintain natural ecosystems in parks? This basic aspect of the national park idea is difficult to implement in a country where human influence is so ubiquitous.
Quite a few animals of the Smokies depend on streams and their organisms without living entirely in them. They live with one foot in the water and one foot on land, as it were. Raccoons out hunting at night patrol streams, alert for frogs, crayfish, and mussels. Mink pursue fish, crayfish, and other animals underwater, flowing downstream through the foam as effortlessly as water itself. Kingfishers perch on overhanging branches to plunge headfirst after small fish. Their loud, rattling calls can be heard on the lower courses of many streams. The small Louisiana waterthrush, a warbler, teeters on rocks in the torrent, searching for aquatic insects. It nests on stream banks or behind waterfalls. Its song, a lovely descending jumble of notes, cascades like the water of its haunts. Harmless water snakes, mottled brown somewhat like the water moccasin (which does not occur in the Smokies), like to sun on limbs or debris near the water. Frogs, fish, salamanders, and crayfish form most of their diet. Of the park’s few species of frogs, the green frog is the one most likely to be found in streams. Aquatic turtles are even less common; most numerous is the snapping turtle, a wanderer that sometimes reaches the middle elevations in the park.
Ducks, herons, and other large aquatic birds, scarce in the park because there are no large bodies of water, do appear occasionally. On the section of Abrams Creek that flows through Cades Cove you may surprise a wood duck or green heron. Though not very productive of plant food, Fontana Lake on the south border of the park sometimes serves as a resting place for migrating waterfowl.
Perhaps we humans could be considered semi-aquatic ourselves, so strongly does water attract us. In the Smokies people love to visit waterfalls, plunge into favorite swimming holes, play among the rocks and white water, and fish up and down the streams. One of my favorite activities is simple stream-watching. Just pick a sunny rock, sit down with your lunch, and watch. That’s all there is to it. Trout will eventually grow bold enough to come out of hiding. Birds fly out of the dense forest to feed in the sunlit shrubs along the stream. Butterflies wander down this open avenue, and dragonflies dart after winged prey. Sometimes the unusual happens. One fine October day as I was just finishing my sandwich, a little red squirrel appeared on the opposite shore, edged down a rock to the water, and plunged in. It drifted with the current and then scrambled out on a rock near me. A swimming squirrel I had never expected to see.
In the Smokies you are seldom far from the sound of water. These tumbling streams—the Little Pigeon, the Oconaluftee, Roaring Fork, Hazel Creek, and all their many brothers—have voices as various as a hound dog’s. They talk, murmur, shout, and sing, rising and falling in tone. Porters Creek once actually convinced me that people were talking and playing guitars on its bank. This is the soul music of the mountains.