Best Practices for Catch-and-Release Trout Fishing

This story was originally titled “Catch-and-Release: Best Practices to Release Your Fish Unharmed.” It appeared in the Fly Fishing Made Easy 2020 issue of Fly Fisherman. 

Lee Wulff famously said in 1938 that “gamefish are too valuable to be caught only once.” It took decades for catch-and-release fishing to catch on, but later generations of North American fly fishers eventually realized that it was a critical way to conserve fish stocks amid a growing population and dwindling habitat. In many places, our angling opportunities would be greatly restricted without catch-and-release ethics or catch-and-release regulations. There simply wouldn’t be enough fish.

Keep in mind, however, that in a few places, a fish population (nonnative trout, panfish) can withstand some harvest. There’s nothing wrong with eating a few fish caught in places where a wild fish population will easily replenish itself, and there aren’t many anglers. I’ve done it myself in high-mountain streams and lakes in the Rockies that are brimming with brook trout. It’s also okay to kill some trout in some put-and-take stocked trout fisheries when the trout are not likely to survive the season due to environmental conditions.

However, if you are going to release a fish, it’s important to do it successfully. Releasing a fish that dies due to improper handling is a waste, and if you catch-and-release many fish this way during the course of a day, you can kill more fish than a poacher who keeps more than his legal limit.

Under optimum circumstances, catch-and-release mortality can be as low as 1 percent. If the water is unusually warm or there are other stressors like improper handling, mortality can be as high as 20 percent or more.

If the water temperature is near or above 70 degrees, catch-and-release trout fishing becomes unethical and impractical, as the mortality rate will be high. In the heat of summer you should look for high-mountain streams that are colder, go bass fishing, or fish in the early morning when the water is coolest.

The best way to release any fish is to do so without touching it. Release the fish by sliding your hand down the leader, grab the fly with a clamp or hemostats, and twist the fly out. The fish swims away untouched. A barbless hook makes this release technique incredibly effective. Regular pliers often don’t have the delicacy you need for small trout flies, and it’s important that your precision implement—much like a surgical instrument—clamps and holds onto the fly for you.

It’s easy to release smaller fish this way. With large specimens, however, you may have to net the fish or otherwise handle it to retrieve the fly without breaking the line. You can’t merely hold the line and twist the fly out.

Handling a Trout

Most fish are covered in a protective slime. If you do handle the fish, keep this protective coating intact. Don’t touch the fish with dry hands, don’t place it in the grass or snow on the bank, and use a net with a soft rubber mesh bag. Net bags made from cotton or nylon are abrasive, which is fine if you are netting a fish to keep, but not if you plan on releasing it.

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All fish have delicate gills, and their internal organs are not protected by a sturdy rib cage like ours. Don’t stick your fingers into the gills, and never squeeze a fish while attempting to hold it or you will injure the fish. Also, the fish will probably pop out of your hands like a bar of soap. The harder you squeeze, the more likely this is to occur.

Instead, gently cradle the trout or other fish with your hands, allowing it to rest/lean on your fingers and hands to distribute its weight. Always hold the fish in the water as much as possible, so the water helps support the fish naturally and all the weight is not on your hands.

If you catch a trophy or even just a memorable fish, you may want a photograph. If you lift the fish from the water, make sure your fishing companion is ready with the camera turned on and lens cap off before you lift the fish from the water. If your photo shows water still dripping from the fish, you probably held it up for the right amount of time.

You can also compose excellent photos with the fish still in the net, or just resting comfortably in your hands and partially or completely submerged.

Waterproof cameras also allow you take photos of a trout in its natural environment without ever removing it from the water. With good light and clear water, these photos can offer a fresh perspective that is generations removed from the old “stringer” photos that our grandfathers seemed to enjoy so much.

If you are fishing alone, don’t put the trout up on the bank to photograph it. This makes for a poor picture, and when the trout flops on the snow, rocks, sticks, or sand, it can injure itself. If you are alone, cradle the fish half in/half out of the water with one hand, and shoot a few close-up pictures with your digital camera with the other hand.

Net or Beach

With big trout and light tippet, using a soft rubber net is better than alternatives, which include overplaying the fish until it is mortally exhausted, or beaching the fish on rocks or sand. Steelhead and salmon anglers in particular have been historically guilty of beaching fish, especially when they are fishing alone. If you can drag a fish into very shallow water, it tips onto its side and can’t swim. While this can work effectively to subdue a large salmonid, too often the fish thrashes on the rocks, making it a poor technique for catch-and-release fishing.

A net, if used prudently on large trout and steelhead, is safer for the fish. I base this conclusion on the many trout I’ve caught in New Zealand, which were netted and photographed before and after me, some of them for many years.

One 10-pound brown trout I caught on the South Island in 2014 appeared on the cover of Fly Fisherman, and afterward I received no fewer than a dozen other photos of the same fish caught in the same spot over the course of eight years. Each time this brown trout was quickly netted, photographed, and survived to take a dry fly another day.

Small fish rarely need to be revived, because you don’t play them to the point of exhaustion. When you catch a large fish on a light tippet, however, you must often tire the fish before you can handle it. In these cases, you should carefully revive the fish before you release it. If you release it too soon, it may tumble to the bottom and die.

Hold the fish facing into moderate current so that cold, clean water naturally rushes through the fish’s mouth and over its gills.

In the summer, when the water is warm, properly reviving the fish is critical. When you revive a trout, don’t do it in warm backwaters or sloughs off the main river. Revive it near riffles where the water is as cool and oxygenated as possible.

As the fish regains its strength, its gills will work faster and you will feel the fish struggle to get away. When the fish feels strong, allow it to slip behind a rock or along the bank where it has some shelter from the current. Do not release a weakened trout or other fish into fast water.

In a stillwater situation, cradle the fish in clean water and allow it to pump water through its gills naturally. There’s no need to “pump” the fish back and forth unnaturally. Try to keep it out of muddy water.

Handling a fish as little as possible and limiting its time out of the water have always been the main tenets of catch-and-release fishing. If you follow these basic steps, the trout (or other gamefish) will likely survive to provide a little excitement for the next fly fisher who comes along, and to propagate the species for future generations. Have fun out there, take some photos, and release ’em alive!

Ross Purnell is the editor and publisher of Fly Fisherman.