Anglers take heart. It’s not always your fault that you can’t catch fish in the usual places.
Sometimes, they’re just not there.
Fish of many species wander – based on season, water flow, temperature or, sometimes, it seems, pure whim – for hours, days or even months a time.
Researchers from Juniata College, for example, are studying brown trout on Pennsylvania’s Little Juniata River. Their work has been ongoing for three years.
They captured trout at three sites along the river and implanted them with radio transmitters. Students and volunteers follow those fish by kayak, foot and car, monitoring how loyal they are to home sites and, if they move, and when, how far and why, said Uma Ramakrishnan, an associate professor of environmental sciences and studies at the college.
Sometimes, those wandering fish get on their horse and ride.
One trout in particular tells that tale.
“That fish moved almost 140 miles in a 30-mile-long river. So it’s up, down, up, down, back and forth, multiple times,” said Dennis Johnson, another Juniata professor.
That fish was a real traveler, Johnson added. But it wasn’t alone in moving.
Researchers break trout in the study into two categories, based on loyalty to where they were when captured.
“We made a decision to say, what’s a mover and what’s a stayer. If they were there 50 percent of the time when we were there, we called them a stayer. If they were gone more than that, we called them a mover,” Johnson said.
More than a few were movers, especially during the spawn.
Students and volunteers counted redds, or trout spawning beds, in the river. They monitored the location of fish near them.
In all, they covered about 20 miles of river.
But some trout simply vanished.
“They disappeared and we couldn’t find them during the spawn. Then, they reappeared later,” said Bill Anderson, president of the Little Juniata River Watershed Association, which helped fund the study.
Presumably they traveled into tributaries. But exactly which ones and when are mysteries, Johnson said. Researchers spent a month looking for them with no success.
“Had the spawned in the river, I feel pretty certain we’d have found them,” he noted.
It’s not just Little Juniata that move that way.
A similar study done on wild brook trout found movers and stayers, too. In that case, researchers from Penn State University found that water flows, temperature and the onset of the spawn sent some trout packing.
Some traveled as little as 164 feet before finding a new home. Others went 5.6 miles.
Younger, smaller fish aren’t always the movers, looking for their own home ranges either.
“It’s not always that the big fish move and the small fish stay,” said Tyler Wagner, assistant leader of the Pennsylvania Cooperative Fish and Wildlife Research Unit. “It’s kind of unpredictable in terms of using size or weight of a fish to determine if it’s going to move a lot.”
Sometimes, fish, even in a lake, seem to move for no reason.
George Toalson, manager and lure designer for Gene Larew Lures and Bobby Garland Crappie Baits, is a scuba diver. He’s spent decades diving in freshwater lakes, observing fish in hopes of being able to better catch them.
One thing he’s learned with crappies, he said, is that some are bigger wanderers than others.
A brush pile, for example, might be home to a certain number of fish. Most are what he calls “homers.” Those are fish he could count on to find every time, virtually under the same limb on each visit.
Anglers might be catching a few, he said, when all of a sudden it seems as if the bite really turns on. Then, after a while, it stops.
Sometimes, he said, that’s not a result of anything the angler has done. It’s not even a case of changing aggression on the part of fish.
It’s that they number of fish to catch changed based on movement. They move in and out.
Those “homers” are joined by “roamers.”
“All of a sudden, there might be a swarm of crappies that comes in. They’ll come in and there will just be thousands of them,” Toalson said. “And they may stay there for quite a little bit and then all of the sudden they disappear.
“And those homers are still sitting there.”
It’s good to know fish movement patterns if you’re interested in habitat, said Anderson. His organization helped fund the Little Juniata River research so as to know how and where to best direct its resources.
“If we can identify places where the fish go to spawn, for example, we can improve that spawning habitat in that area. If there are spring refuges, we can protect those refuges,” he said.
But if you’re just trying to catch fish?
Well, good luck. Sometimes they’re there and sometimes they aren’t.