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| ARKANSAS RIVER
BROWN TROUT BENEFIT FROM DROUGHT
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Most anglers believe the drought that lowered Colorado’s stream
flows for the past several years hurt trout fishing. But it was a
boon for Arkansas River browns, creating an ecological environment
that amounted to trout steroids. Low, clear stream flows created a
bonanza of bugs for the trout to feed on and lack of runoff
lengthened their feeding summer, growing larger, healthier and
more fish for anglers to enjoy.
The Arkansas River runs 300 miles from above Leadville to the
Kansas state line. It offers abundant public access from Colorado
Highway 50 and some of the purest dry fly fishing the state has to
offer with its world renowned caddis hatch.
Different insect hatches are relished by fly fishermen because,
depending on the intensity of a hatch, they can induce a trout
feeding frenzy with fish frantically devouring bugs floating down
the surface of the river. During big hatches in stretches of water
with high concentrations of trout, the surface boils with fish
competing for the floating delicacies. In such frenzies, trout are
very susceptible to imitations of whatever insect is hatching and
“dry fly” fishing is the technique most enjoyed by fly
casters.
The geographic features of the river make the Arkansas's aquatic
habitat more responsive to low flows. The river runs through a
steep and confined basin which means once flows hit between 450
and 500 cubic feet per second (cfs) the river doesn’t grow
wider, it gets faster and deeper.
“The Arkansas is unique as far as Colorado rivers go,” said
Greg Policky, aquatic biologist for the Colorado Division of
Wildlife (DOW). “We don’t really have a low flow concern here
when it comes to the fishery.”
The climate in the Arkansas basin also helps protect the fishery
during drought years. The basin is fed by water from some of the
highest mountains in the state and air temperatures there drop
dramatically at night. Nighttime lows protect fish from
drought-induced high water temperatures. And if they do reach
levels detrimental to trout there are always deep pools and shaded
banks where fish can escape the effects.
“Last summer, water temperatures near the town of Parkdale
reached into the 80’s in the riffles,” said Policky. “Yet we
never saw any visible signs of stress in the fish, let alone a
die-off.”
Flows during a normal year’s runoff can be far higher than 1,000
cfs and augmentation water added from storage reservoirs may keep
the river flowing close to 700 cfs throughout the summer. This is
good for caddis, one of the few aquatic insects that actually does
better in a fast-flowing river, but bad for trout. Fish cannot
feed efficiently in high stream flows. They hold under banks and
behind boulders out of the current and cannot venture into the
fast-flowing water to forage. Since the waterborne bugs they feed
on are also moving past them at a high rate of speed, the trout
have more difficulty catching them.
But last year’s dry winter left very little snowpack to create
runoff, there was no stored water available for augmentation and
the fastest the Arkansas ever flowed was 700 cfs. During the
critical summer feeding time for trout, from mid-July to Labor
Day, flows slowed to between 250 and 400 cfs -- optimum trout
habitat, according to Policky.
This increased fish density and the survival rate of naturally
produced young of the year brown trout, which spawn in the upper
reaches of the Arkansas. Policky said the trout biomass doubled
per mile of river. The numbers of fish over 14 inches increased
eightfold and all the fish were healthier.
Rod Patch, owner of the Arkansas River Fly Shop in Salida, and his
fly fishing clients are reaping the benefits.
“The Arkansas has always been a great brown trout fishery, but
some people didn’t rank it as high as some of the other trout
streams in the state because you didn’t have the ability to
catch bigger fish -- fish that were 16 inches or larger,” said
Patch. “Last year, with the low water, the browns responded like
never before. The fish we are seeing now average an inch and a
half to two inches longer than they have ever been.”
This year’s spring caddis hatch has crept its way up past Salida
and is expected to last until runoff comes in the beginning of
June. But anglers who have yet to take advantage of the
drought-fattened trout will have plenty of opportunity throughout
the summer, regardless of the caddis hatch, which was smaller than
in previous years.
Caddis can endure fast water because a hard case protects their
sub-surface nymphs from strong currents. The nymphs of most other
aquatic insects such as Mayflies and stoneflies are not protected
by hard shells and simply cling to the rocks in a river, thus
being more easily washed away in high flows.
There are the usual stories of caddis bugs being so thick they
coated the windshields of cars and anglers having to breathe
through their teeth so as not to inhale the critters that add to
the mystic of the Arkansas. There are several other “buggy”
events promise excellent trout fishing post runoff with less
angler pressure.
Mayfly hatches, for example, have been huge.
“We’re seeing a lot of different Mayflies come off,” said
Patch. “The whole ecology or whole world that exists below the
surface of this river benefited last year from the low water.”
Golden stoneflies, which begin hatching when runoff slows at the
end of June, are expected to be equally prolific.
“Bugs are impacted just about the same as trout are,” said
Policky. “This summer bodes well for stoneflies based on their
life characteristics. Late July August and September the fishing
should be phenomenal also.”
Caddis and stoneflies aren’t the only option for fly fishermen
who enjoy drifting dries. July and August are also great months
for fishing terrestrials.
“We also have great hopper fishing here on the Arkansas,” said
Patch. “Big attractor flies like Royal Wulfs and stimulators.
Fish are conditioned to look to the surface for food, so big dry
flies work well. The next significant hatch is a pale morning dun
hatch we get those coming off in late July. Red quills also come
off all summer long.”
Looking ahead, Policky expects a continuation of optimum trout
habitat on the Arkansas. Because many reservoirs are only at 40
percent of capacity, augmentation flows in the Arkansas are
expected to be cut back to refill them, resulting in another
summer of low flows and extended feeding for trout.
Runoff, which normally takes place in June, remains an
imponderable. Sustained high temperatures create a strong,
short-term runoff while gradual warming results in less severe
runoff for a longer period of time. Policky believes that a heavy,
short-term runoff would be best option for the fishery. A quick
blast of water down the basin would wash down much of the sediment
collected on the river bottom and would allow fish to begin
feeding earlier and give them a longer foraging season through the
summer.
“Channel maintenance type flows would be a benefit to the
fishery,” Policky said.
All of the fisheries in the Arkansas basin are in good shape and
should provide some great recreation throughout the summer. Trout
in the high mountain lakes saw close to an extra month of ice-free
feeding time because the drought shortened winter weather patterns
in the high country. And many of the trout stocked in reservoirs
last year remained uncaught because of low fishing pressure. These
fish have grown to prodigious size and been joined by newly
stocked trout this spring.
“Overall,” said Policky. “There is absolutely no reason for
fishermen to stay home this summer.”
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