Leaping Trout by Winslow Homer, 1889
Fish Plan
Lillian, the administrative assistant, said the regular audit of the Fisheries Division had taken weeks. What could take weeks in the cramped Division office or the regional offices, which share space with parks and wildlife people? Checking management plans, budgets, inventory. What would be their main asset? Fish, of course, trout in particular! There are other fish in Montana, but precious few other trout territories in the world, one reason their numbers carry weight with fisheries managers. How many they have, where they are, and what they are up to. To count and plan for a moving inventory must take a little doing.
Fish biologists have a number of means of conducting a census—such as seining, gill-netting, and electrofishing—but none of these methods gather all the fish in. And while electrofishing at low voltages does not injure fish, it irritates them. They are not about to count off after being electrified.
If field technologists round them up in boats, using nets and the banks of lakes and streams as corrals, there is still the line problem. Even when they are feeling good, trout don’t swim straight for any distance. One unfortunate trout with whirling disease can throw the whole parade into a stampede. Add the fact that trout will watch many a meal fly by to avoid hooks and lines. Fish biologists must have a difficult life. They want to get this count done and there is no practical way to do it. No wonder they use estimates.
They use estimates, too, for an inventory essential to the well-being of trout—bug counts. Caddisflies, salmonflies, stoneflies, blackflies, among them. Since the 1940s, the Fisheries Department has hand written, cut and pasted, and typed their numbers into thick bound stacks of crinkly paper, and smooth laser printouts. Diptera/mosquitoes appear in these counts, but because they like warm waters, they have little status in trout plans for coldwater lakes and streams. Wherever there are plenty of choice invertebrates, there are trout in quantity, and big. As with trout, the numbers are the thing—the more the better!
Lately, the rising popularity of walleye as a fighting predator and tasty dinner has led to many new records of them and their diet of choice—other fish. Although not natives, they are found in lakes and reservoirs in Montana and expected to stay there. It’s been thought that walleye wouldn’t swim into cooler trout habitat in the little streams that feed lakes and rivers. But no one knows for sure, because wildlife combined with habitats’ myriad variables are most difficult inventories to track. They not only move, they change.
In Montana’s early years, fish and game managers, a hardy breed and few, stocked streams and lakes to give anglers an even chance against trout and to make up for lost populations. Some dropped fish out of airplanes into every available mountain lake in the Beartooth range. If they could get to a stream with packhorses and buckets, they stocked it that way. As they learned more about Montana fish, they determined that matching them with congenial habitats was an excellent way of keeping fish populations healthy and growing. So, they began to look at returning streams which had been altered by mining, logging, flooding, and other activities to their former condition. They also began returning native fish to their former home streams and lakes.
Just what happens when landowners, agencies, and groups restore habitat depends on the site and resources they have. Gathering more than enough water to float a toothpick is the #1 priority. Riprap, which used to be old tires, or even cars and dryers, but is now, for aesthetic and health reasons, rocks, covers and weights down banks to keep them from eroding into the water. Riparian fences prevent livestock from trampling down stream edges and leaving muddy footprints. Planted metal barbs that look like upside-down skeletons of ships’ prows with little curved hooks sticking out here and there hold banks together. They keep waders alert and make floaters’ days interesting too.
And then there are tree or is it root wad revetments? Just try to guess what that means. Heavy, wrapped bundles of tree trunks and limbs, or brush, plunked down alongside sagging streambanks to buck them up and create little nooks and crannies for trout. The person who drops one in the wrong spot has a ton of soggy lifting to do. Bulldozers push the dirt around to put kinks in streams that run too straight and fast. With enough devices and plantings of shrubs and grasses, planners and laborers can makes a creek look as if it had never had a bad day. It will turn and sparkle under the sun; it will have swirls and eddies and pools; and where it races, it will not carry dirt and gravel, but will jump cleanly over and around boulders in the streambed.
With habitat restoration on the way, all counts in hand, and the audit completed satisfactorily, we can make an objective comparison of walleye and trout to assess their futures in Montana’s famous fisheries.
There is mainly one kind of walleye—ugly, without finesse. Representing trout, let us have bull trout—plain as trout go, not bright, no music at all in the name. A good match. Oh, you query with a skeptical look, lack of finesse and brightness in fish? Walleye eat anything crunchy. Bull trout lack a sense of caution. They don’t cagily swim about in plain view, from rock to rock, and watch flies for hours, while fishermen die of old age. If something moves into their space, they bite it.
Walleye have dead-looking eyes and spiky fins. They tend toward yellowish-grey, not a good color next to boulders. Walleye pretty much stop eating bugs when they reach 1 1/2 inches and feed on other fish for the remainder of their lives. If they didn’t have other fish to eat, they would probably feed off the bottom, on unidentifiable dead objects and gravel. They can shoot past 28 inches before their third year. They are limber or timber, as the mood takes them, and heavily armored. Given their spectacular teeth sets, sharp gills, and raspy skin, extreme caution is called for in handling them. Some combination of tongs, heavy leather, and a chain and pulley apparatus or chain mail might be useful – whether or not they play dead. Walleye like quiet, murky, warm waters. They prefer the dark, wouldn’t you know?
Bull trout have marbley eyes, hence a scared, vulnerable look, and scarlet spots. It would be unfair to bring up rainbow and cutthroat trout with their wonderful pinks and greens, silvers, and orange and scarlet slashes. They all will feed on insects. Most stream trout live on invertebrates, with occasional snacks of passing fish for variety. What trout eat in lakes is another story. Bull trout, it must be admitted, scrape their bugs off streambeds and snack often, on slimy sculpins and whitefish.
Little brown trout, which are suspected of eating other trout on a regular basis, would eat walleye if they could. They can’t grow large enough, fast enough, to swallow them. Brown trout are potentially one of the longest of trout, but their battlecry is “divide and conquer.” They raise so many families so successfully that the food supply in streams often can’t meet the demand. Any trout under, say, 14 inches, swimming back into its old home lakes and reservoirs is at the mercy of prowling walleye.
In Montana, trout must be aged grandfathers to reach 18 inches in streams, and are rare sights at 39 inches, even in lakes. They must have exact right water temperatures, brushy willows and dogwood, clean gravel, fallen logs in streams, gentle side pools, and narrow, deep, meandering channels. For this habitat they will migrate, spawn, linger and grow. Unless a bull trout can stay in a healthy, deep stream minus heavy competition or make it to the far offshore waters of a lake and survive a couple of winters, it can’t flourish and raise families. You can see the stringent requirements trout must meet, and their dilemmas.
This does not mean that each species will keep to its place and that no other measures are required to keep trout and walleye away from each other. Will you note well the differences between the species’ needs? And do not, for pity’s sake, try to say walleye need help. Walleye can survive and flourish in rusty bathtubs. Walleye will swim back and forth through a long, muddy tunnel if there is food and someone will warm the temperature now and then. If trout can’t have clean water, creative turns, and woody debris, they disappear.
What about Darwin’s theories now? The native has all the variations and little tolerance. The basic prehistoric model seems to thrive under difficult circumstances. How will it do in an excellent environment? Before saying that the habitat preferences of the two species will keep them apart, let us extrapolate on how they might adapt to habitat improvements, and what changes habitat restoration has effected.
The walleye may be advancing into streams stabilized, narrowed, and deepened for trout. They may not like, but they tolerate temperatures down to 0° F., well below trout stream limits. They may be slinking around rock vanes and finding shelter under the same log deflectors intended to give cutthroats and bull trout air-conditioned cover in the summer. The more trout, the easier hunting. The invisible boundary of coldwater temperatures that should ward off walleye could be moving swiftly upstream.
Now, because of habitat restoration, not only the trout have problems. What if the lowly mosquitoes ignored in trout plans adapt to coldwater habitats too? What if they learn to like mountain streams because the vegetation newly planted by Trout Unlimited and Flyfishers, Int. hangs so invitingly thick and green over them? Then improving trout habitat may be aiding and abetting both invaders, one going up and one coming down.
Mosquito populations may be growing larger and larger—leaving long nests of huge larvae primed to hatch and grow one of these springs when the right combinations of riparian habitat, gravel, moisture, water temperature, and high streamflows occur. Ready to rise from their shaded, damp dwelling places, maybe even earlier than spring—on some late October night! There in the perfect trout/insect habitat, swirling, buzzing chants, rubbing their pointy probosces on serrated legs, putting a fine edge on. Knowing instinctively that within the flying distance of no more than a generation, 50 short miles, are helpless people donating time, money, and effort to conservation. They may not smell blood, but they count on it. They’re too big to swat; they can’t even sniff mosquito repellent: it’s too weak and far away at the tips of their two-inch noses. And then it happens—living inventories, planning and work, past and present, and the unforeseeable converge.
One last full-grown mosquito hatch of the year rises under the harvest moon, black and speckly against its soft apricot glow. Millions of mosquitoes draw a collective breath of confident anticipation, bank between bare twigs overhanging the stream and turn as one entity in formation, toward the distant lights of human habitation. As the cloud suspends itself above black waters, there is a joyful rushing sound—a million splashes thrash and boil the waters; the stream lifts 5 feet—there is a glimpse of flashing, twisting. striking silver—tails, fins, shimmering curved torsos doubled, then gone, part of the murmuring waters. . . .
Nothing remains above the dappled grey and white surface. Every mosquito has disappeared. A shocked silence usurps the night sounds of chirping and rustling. Beneath the reassuring gurgle of the stream, a vision of shadowy banks of trout grows clearer through the wavering moonlight and rippling flows. Huge, huge, YOUNG trout, not one smaller than 18 inches, packed so closely together they seem to move as one entity in formation. Eager brown trout kept at a safe distance by rainbow herders. All of them hovering, finning the waters gently with their tails as they glide swiftly downstream, with sidelong glances at next year’s mosquito larvae. Adding numbers and momentum from tributary creeks, they stream over boulders and spill down evergreen mountain slopes, coursing as the river between widening banks, racing toward warm water and walleye! The bigger, the better.
by Kathleen A. Curd Rau, Helena, Montana
Copyright © 1998, 2002 by Kathleen A. Curd Rau. All Rights Reserved.
Jeanne Robertson
Every Good Gift Montana