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Balancing angling opportunities and fish health during a hot, dry summer

Fishing

Fri Jul 01 15:35:00 MDT 2016

Protecting the principle
By Greg Lemon

FWP Information Bureau Chief

In Montana, where angling is a year-round pursuit, fishing is on the brain constantly.

In the winter, unless you’re an ice fisherman, it’s all about anticipating the coming year – tying flies or Googling the best new gadgets for your boat and tackle box, or just obsessing over the online map of Montana’s snowtel sites. In Montana, we know that what we ski on in the winter, we float on in the summer.

And so anglers were feeling pretty good early this year as winter slipped into spring. Snowpack wasn’t great everywhere, but it was solid in most places and we were set up nicely for summer.

Then April happened.

You can credit climate change. You can call it global warming. Or just blame El Nino. Debate any of the causes, but the fact is April was warmer and drier than normal and all the snow typically stored in the high country until May or June came off early, setting up the second consecutive year of extremely low and warm river flows.

As we head into the dog days of summer, many of Montana’s most popular rivers are flowing below 25 percent of normal stream flow. Temperatures are climbing steadily and fishing restrictions are already in place for stretches of the Big Hole, Beaverhead, Jefferson, Ruby and Madison Rivers in southwest Montana. More are anticipated in the coming weeks, particularly on the Jefferson, Blackfoot, Clark Fork and Bitterroot Rivers, according to Montana Fish, Wildlife and Parks officials.

Ahead of the game

The public might not be aware of the dire situation facing many of Montana’s coldwater fisheries this summer, but FWP fisheries staff have anticipated this for months and are ready to act quickly to protect fisheries and work with all water users on mitigation strategies.

Every year FWP fishery biologists are monitoring stream conditions around the state, both in the coldwater and warmwater systems. This monitoring includes the U.S. Geological Survey’s stream gauges available in near-live time on their website, as well as FWP’s own equipment to monitor stream flow and temperatures, said Joel Tohtz, FWP fisheries management bureau chief.

“If you’re doing the work that we do for the fisheries, it’s just part of an annual assessment you follow no matter what kind of year,” Tohtz said.

However, when the extreme years happen, the early monitoring efforts are important.

Biologists around much of the western half of Montana knew conditions could get dire after April’s weather melted much of the snowpack. The moisture came in May and June, but the runoff that started in April wiped out the snowpack two to three weeks earlier than normal, said Stephen Begley, FWP water conservation specialist.

“While May provided its share of precipitation and below average temperatures, the trend did not continue into June,” Begley said.

Under normal dry and hot years, fishing restrictions may be in place for a couple of days or weeks in early August on rivers like the Big Hole and Lower Madison, where flows and temperatures are regularly problematic. However, this year those restrictions come just as the summer fishing season was getting underway.

In some stretches of these rivers, the flows are below 25 percent of normal, said Travis Horton, FWP Region 3 fisheries manager in Bozeman.

“That’s largely because we should still be in runoff,” Horton said.

Low flows coupled with hot weather have caused river temperatures to begin to climb dramatically. Fishing restrictions are the first line of defense at protecting the fishery. The goal is to shift fishing pressure to the time of day when water temperatures are the lowest while protecting fish during the heat of the day. On a normal summer day, the river temperatures peak late in the evening and then plummet until they bottom out in the wee hours of the morning. Some rivers can see temperatures swings of 10 degrees or more. So typically FWP implements hoot-owl closures which prohibit fishing from 2 p.m. to midnight daily until conditions improve.

In general, the trigger for fishing restrictions is water temperatures hitting 73 degrees for three days in a row, Horton said. That can change depending on the river and if there is a drought plan, but in general that’s the rule around the state for coldwater fisheries.

Fish stress

Most people know that trout are stressed as the water warms. However, by the time the water is 73 degrees for three days in a row, the fish have likely experienced a significant amount of stress already.

Salmonids, which is the fish family that includes trout and mountain whitefish, need cold water to thrive. However, most species can survive moderately warm water if they are left alone.

Cold water contains more dissolved oxygen, which decreases as the water warms. Trout need the dissolved oxygen to survive and recover from being caught. That’s one reason catching a fish in warm water can be lethal – there just isn’t enough oxygen in the water for it to recover. But as water warms above a certain level, the heat itself can be a problem. A trout’s metabolism increases with water temperatures and declining oxygen, making it difficult for them to maintain their health.

This summer FWP is working to inform anglers on proper catch and release techniques. Making sure the fish you catch lives once it is released means keeping it in the water as much as possible and making sure you don’t fight it more than necessary. These points are even more important as water temperatures rise.

Montana’s salmonids thrive in water temperatures below 60 degrees. Bull trout are the most sensitive to temperature, followed by cutthroat, then whitefish, rainbows and brown trout. So even if water temperatures don’t reach the level for fishing restrictions, they’re still high enough to cause fish extra stress and reduce their chance of survival if played or caught by an angler.

For instance, on the upper Bitterroot River, biologists start seeing dead fish once the water levels get to 68 degrees, said Pat Saffel, FWP Region 2 fishery manager in Missoula. Typically these fish are westslope cutthroat trout and generally about the size most commonly caught by anglers.

It’s important to consider fishing during morning hours when the water is cooler, even if fishing restrictions aren’t in place yet, Saffel said.

The balance

In managing fisheries, balancing the health of the fish and opportunities for anglers can sometimes be a challenge, particularly when conditions require restrictions.

Last year when restrictions were necessary on the Bitterroot River due to water temperatures, it got complicated when weather would change for a couple of days, Saffel said.

A couple of cloudy, cool days can drop the water temperature peaks below 73 degrees, but not significantly impact the trend. Lifting restrictions and putting them back into place on a week to week basis just doesn’t make much sense.

“Then you’re just chasing the weather,” he said.

Ultimately, the first priority is to protect the fishery, said Tohtz. Often that can be done with balancing opportunities and protection, like with hoot owl restrictions.

“Protecting the fish is just like protecting the principle in the bank,” he said. “You try to give people as much opportunity to enjoy the fishery without doing harm to it.”

Hoot owl restrictions are currently in place on the Big Hole River from Saginaw Bridge on Skinner Meadows Road to Dickie Bridge and from Notch Bottom Fishing Access Site to the mouth of the river near Twin Bridges. On the Madison River, restrictions are in place from Ennis Dam to the mouth of the river near Three Forks. On the Beaverhead River, restrictions are in place from Anderson Lane to the mouth of the river near Twin Bridges. On the Ruby River, restrictions are in place from Duncan District Road near Sheridan to the mouth of the river near Twin Bridges. Restriction are in place on the Gallatin River from Shed’s Bridge Fishing Access Site to the mouth of the river near Three Forks. Hoot owl restrictions are in place on the entire length of the Jefferson River.

More hoot owl restrictions are likely to come soon.

The lower Blackfoot River is already pushing 70 degrees at Bonner. The Bitterroot is climbing above 64 degrees everyday near Darby and that’s far higher than normal for this time of year, Saffel said.

The forecast for July - above average temperatures and below average precipitation.

For complete information on restrictions and closures, check out FWP’s webpage at fwp.mt.gov/news/restrictions/.