Catch and Release Today
From the Outdoor California Magazine
a Publication from the State Department of Fish and Wildlife
article by Victor Johnson
If all fish were killed after being caught, the fish mortality rate would be 100 percent. With proper catch-and-release techniques, the fish mortality rate would be significantly lower.
A 1944 study showed a catch-and-release mortality rate of 5 percent to 35 percent.
A 2005 study showed a catch-and-release mortality rate of brook trout held out of the water for more than two minutes resulted in half of them unwilling or unable to swim.
A 1992 study on hooking mortality of non-anadromous fish had an average rate of less than 12 percent. Under the best conditions, with barbless flies or lures, the percentage dropped to less than 3 percent.
A 1979 study on juvenile steelhead trout showed that treble barbless hooks had 4.5 times the losses from single barbless hooks.
A 1992 study found that after rainbow trout had exhaustive exercise and were exposed to air for 30 seconds, their mortality rate increased by 38 percent. When these trout were exposed to air for a minute, their mortality rate increased by 72 percent.
Depending on the various study, it appears that barbless hooks reduce fish mortality by about 50 percent. The results of the study indicate going barbless offers the most effective catch and release practice for anglers.
National non-profit organization Trout Unlimited conducted a review of current science of catch and release and concluded that fish should be exposed to air no longer than 15-20 seconds. Picking up fish by their lip as part of the fish capture is bad practice if the fish is out of the water. It can dislocate the fish's jaw.
Use of mechanical lip grabbers resulted in 40 percent of bonefish having severe injuries. Increased mortality naturally followed.
A 2002 study on bluegills showed a mesh-type landing net caused mortality in 4 percent to 14 percent of the time. The research indicated knotted mesh nets had the highest mortality rate and rubber nets had the least.
A study of bluegills that were deep-hooked showed 44 percent died within 10 days of removal, whereas only 12.5 percent died when the hook was left in place. The results of the study argue for cutting the fly from the tippet in deep hooked fish.
Some question catch-and-release benefits. Like so many things in life, people can look at a variety of statistics and draw totally opposite conclusions. In most of the world, fly fishermen have adopted catch and release techniques that result in low mortality rates for fish. The rationale is that if a high percentage of catch and release fish live and are available for anglers in the future then opportunities that is the greater good.
A few countries, including Germany and Switzerland, feel that it is wrong to release fish that have been injured by being caught. Therefore, they have banned catch and release fishing. Personal fishing in these countries is solely for immediate food consumption. Although catch and release is a common fly fishing ethic in the U.S., in Yellowstone National Park it is illegal to release lake trout that have been caught in Yellowstone Lake and brook trout caught in Yellowstone's Lamar Drainage. These fish are non-native and park authorities want to return the park to having only native fish.
Current state of good practices: Anecdotal evidence suggests most anglers understand the benefits to practice catch and release, and there seems to be a general consensus on the following best practices:
Use barbless hooks and attempt to remove the fly from the fish in 20 seconds or less.
Do not keep a fish out of the water longer than necessary. This is not as much of a problem for smaller fish, which can usually have their barbless hook removed in the recommended 15 to 20 seconds.
If a photograph of the fish is wanted, have the camera ready so as not to have the fish out of water for any great length of time.
Use wet releases, if possible, for all fish-getting them out of the water often creates undesirable effects on the fish.
Outdoor California Magazine - Vol. 79 No. 3 - May June 2018 issue