It had been about two months since my brother-in-law Chris and I had last fished for trout when his email suggesting a day trip showed up in late July.
But where?
We ruled out the mountain streams in Maryland and Virginia, figuring water levels would be low. And the big lakes that hold trout, such as Deep Creek Lake in western Maryland, aren’t much fun to fly fish.
Then I recalled that up in northern Pennsylvania there is a section of Pine Creek they call “the stretch.” The local fly shop stocks it full of big brown trout for catch and release fishing. Even if water levels were low, we could hit that for the day.
But when I called up the Slate Run Tackle Shop website, it warned against fishing for the browns. Something about high water temperatures threatening the fish.
Since for Chris it would be a five hour trip to the Pine, we settled on the closer Gunpowder River near Baltimore, a pretty little stream that the state and local Trout Unlimited group has turned into a world-class fishery.
When we hit the Gunpowder, the air was hazy, hot and humid, over 100 degrees in the sun. But it is a tailwater fed by the Prettyboy Reservoir Dam and pours out 55-degree water, a perfect temperature for trout. And in a wild effect, the mix of cold water and hot air created a thick and cooling fog that took the edge off the heat.
We fished for about six hours, and by the end of the day, we had caught and released a few. We stopped at a local bar for a perfect crab cake made mostly of backfin lump meat, and headed home.
The next day I returned to the Slate Run Tackle Shop webpage to find out more about heat and trout. I used to carry a stream thermometer but never used it because the water always seemed right when I fished.
“Unfortunately, trout fishing has come to an end on Pine Creek for the foreseeable future. Water temperatures have settled well into the 70s on Pine Creek pretty much throughout its length. Although trout fishing is legal year-round in ‘The Stretch,’ and many trout can be found throughout the 2.8-mile special regulation waters, ethically, we are asking anglers to, “voluntarily refrain from targeting trout anywhere in Pine Creek,” said the website.
Imagine that: a tackle shop telling trout anglers to go away.
As I read on, I learned why: warmer water stresses fish due to a lack of oxygen and an added battle with a fishing line can be lethal.
A little more research turned up recommendations that anglers keep their summer fishing to when temperatures are cooler. “A good way to combat the adverse effects of the heat in the summer is to fish either in the morning or the evening. The water temperature will be highest in the middle of the day,” said the webpage from Colorado’s Angler’s Covey.
Still curious about the impact of warm water on trout, I put in a call to Dave Rothrock, a guide, author, and casting instructor who I call the “trout professor.”
He told me that trout begin to feel stressed in water temperatures of 66 to 67 degrees and that nobody should fish for them once a stream reaches 70 degrees. And that means that on the East Coast, “nobody should be fishing on a vast amount of our waters.”
Rothrock explained that as water temperatures rise, the amount of dissolved oxygen in the water decreases. And that makes it hard, or impossible, to deal with the buildup of lactic acid created when a trout battles an angler.
“They can’t get rid of it, and it becomes lethal in warm water,” he said. “People will tell you that the fish looked fine when they released it, but in fact, it goes to the bottom and dies,” he added.
And forget the advice to fish early and late in the day, said Rothrock. He said that morning water temperatures in summer could read 67 degrees but by midday can hit 74 degrees. So fish thrown back in the morning will be stressed, and those fished in the evening are already stressed.
“Paul, I have an option for ya,” he said. “Go bass fishing instead.”
Paul Bedard is a senior columnist and author of Washington Secrets.
