Anglers “must carefully and immediately return a fish to the water body from which it was taken, that does not meet size or species restrictions, or that a person chooses not to keep”. (36CFR2.3(d)(7)). Catching and releasing fish to minimize stress and injury takes care and practice. When done correctly, catch and release methods can result in very high survival rates. The following tackle, landing, handling, and release methods are recommended.
Before deciding to fish, ask yourself whether the water conditions are such that fish are already under stress. When flows are low, water temperatures high, and fish are concentrated into small areas, fishing can cause additional stress and high mortality. This reduces future fishing opportunities for everyone. In such instances, we recommend you curtail fishing, and just enjoy watching the fish, and your surroundings.
- Using appropriate fishing methods and gear type for the size and species of fish you are pursuing is perhaps the most important factor determining the stress a fish experiences and whether it will survive being caught and released.
- Use rod, reel, and line of sufficient power and strength to land the fish quickly—Long struggles on light fishing gear can tire and stress fish unnecessarily.
Limit the Use of Bait
- Using bait often results in deep hooking injuries. The use of scents and artificial baits that encourage fish to swallow hooks is not recommended. Possessing or using live or dead minnows or other bait fish, amphibians, non-preserved fish eggs or fish roe is prohibited in fresh waters within National Parks, except in specially designated waters (36CFR 2.4(d)(2). Consult the fishing regulations before using baits in National Parks.
- Use artificial lures or flies— Fish are generally hooked in the lip, allowing the hook to be removed easily and quickly.
- Use properly sized, single point barbless hooks— Using small, single barbless hooks reduces fish handling time and injury. Two hooks can be removed from treble hooks using wire snips or pliers. Barbs can be removed by flattening the barb against the hook shank with needle-nosed pliers or fishing hemostats.
Catching and Landing the Fish
- Closely attend your rod or line—National Park Service fishing regulations require anglers to closely attend their rod or line (36CFR2.4(d)(1)). This greatly reduces the opportunity for fish to swallow hooks deeply.
- Avoid playing fish to exhaustion and release quickly— Land the fish as quickly as possible. A tired fish takes longer to recover.
- Use a landing net to avoid injury— Landing nets reduce handling time, reduce stress and the potential for injury, especially for large fish that are difficult to manage. Large net frames with shallow nets made of rubber or small, soft, knotless mesh, are best.
Handling Your Catch
- Keep your fish wet and calm. Removing fish from water causes stress, suffocation and possible internal injury.
- Keep fish properly supported—Avoid removing fish from the support of the surrounding water any more than necessary. Support the fish in a landing net, or cradle the fish gently with one hand beneath the belly near the water surface.
- Treat the fish gently - Avoid squeezing tightly. It can damage internal organs and muscle tissue. Never hold a fish by the gills.
- Use wet hands or gloves to handle fish— Using wet hands or gloves will help reduce the loss of a fish’s protective mucus.
- Remove the hook quickly - Keeping the fish in the water, or holding the fish upside down may calm and relax the fish allowing quick hook removal.
- Use the right tool—Needle-nosed pliers, hemostats and other hook removers, are an essential tool for quick and efficient hook removal.
- If necessary, leave the hook!—If the fish is hooked deeply or the hook cannot be easily removed, leave it. Cut your line as close to the hook as possible.
Releasing Your Fish
Do not release your fish until it is fully recovered. Hold your fish underwater, in an upright position, or secured in the landing net. Ensure it is ventilating and fully recovered before release. You should notice the gills opening and closing. If the fish has difficulty regaining its strength, face the fish into the current so that fresh oxygenated water can pass gently over the gills helping the fish to “catch it’s breath.” Let it swim forcefully away on its own.
In fast moving water, consider the need to move the fish to calmer water where it can recover and swim away on its own without being swept away or injured by fast moving or turbulent water. This is particularly important if the fish is released from a boat in midstream.
Releasing Fish Caught in Deep Water
When a fish is caught from deep water and brought to the surface, gases dissolved in the blood come out of solution and cause the swim bladder to expand. The damage and stress that results is called “barotrauma”. A fish can often survive this event if it is treated and released properly. When releasing fish caught at depth, know the correct procedure to puncture the swim bladder and release the excessive air, or know how to use a “fish descender” to return the fish to the depth at which it was hooked. Learn more about returning a fish to deep water.