Does "catch & release" angling really work?

The province of Ontario has 400,000 lakes, rivers, and streams that support fish. According to Statistics Canada, there are over 700, 000 active anglers in the province. At first glance, these numbers would suggest minimal angling pressure. However, due to the size of the province and the remoteness of most water bodies, many of Ontario’s fish are simply not accessible for the average angler. Fishable water in close proximity to urban areas tends to see significant and sustained angling pressure. To manage the resources, especially in popular, high-traffic areas, we have a controlled and selective harvest for each fish species. Seasonal regulations, size limits, bag limits and slot limits, together with catch and release techniques are used to reduce environmental impact and to maintain a healthy fishery with adequate brood stock for population maintenance.

History has taught us that fish populations can be fragile, and over-harvest of popular species can decimate a lake’s population and lead to some pretty terrible fishing. So now, catch and release fishing is widely used by anglers as a conservation mechanism for the preservation of our fisheries. The efficiency of catch and release fishing has been studied for nearly half a century, and the effectiveness of the practice has been debated for just as long. Because of the variety of techniques used in both the angling (catch) and the handling (release) of fish, the success of catch & release angling has been very inconsistent.

Historically, observation was been the method used to justify the catch and release concept. Fish were caught, unhooked, and then observed to either swim away, or die. As recreational angling grew in popularity throughout the twentieth century, the need to accurately determine catch and release fishing's actual effect on fish mortality became obvious. Fortunately, recent studies, in a wide range of environments and on many fish species, feature post-release observation methods and long-term data collection that can provide accurate information to sport fishermen and resource managers.
The long term use of catch and release fishing in observed fisheries, such as the Portage Creek Steelhead Study in Northwestern Ontario, has provided a significant amount of data documenting its efficiency as a tool for the minimization of environmental impact. Other recent studies have provided additional insights into the effects of various tackle and techniques as a means to reduce fish mortality. I’ve read some of the studies on fish mortality caused by human activity, and they’re pretty dry. However, a few key factors in fish mortality are worth sharing. With specific tackle and handling techniques, the success of catch and release programs can be significantly improved.
While most people release all their steelhead and smallmouth bass, certain types of fish, like walleye and lake trout, are targeted for their value as table fare. However, nobody keeps every fish they catch, and with most small and trophy-sized fish being returned to the water, proper catch and release techniques are essential. There are two major factors affecting the success of catch and release angling: the hooking location, and the degree of physiological stress suffered by the fish. Understanding which fishing methods decrease the chances of 'deep-hooking' a fish, and avoiding the factors that lead to elevated physiological stress in fish can help the average angler contribute to healthier fish stocks in Ontario’s water bodies.

Key Factor #1 – Hooking location

For obvious reasons, the location of the hook wound is the single most important factor influencing a fish’s chances of survival. It has been consistently shown that deep-hooking, in the esophagus or gills, leads to high mortality- up to 35% when accompanied by bleeding. In comparison, when a fish is hooked in the mouth or jaw area, mortality is negligible, typically less than 1%.

Most anglers can relate to this fact after seeing a deep-hooked fish swim away, only to float to the surface a short time later. On the other hand, many anglers can also testify to catching the same fish twice in one day, sometimes with a lure and a piece of broken line hanging from its yap!

The location of the wound site has been demonstrated to be affected by hook size, type, the use of natural bait versus artificial lures and angling techniques. Recent studies have shown that using barbless or circle hooks instead of “J” hooks, and artificial lures instead of bait will significantly increase a fish’s chance of survival after release. In addition, using angling techniques like jigging or trolling result in far fewer deep-hooked fish than live bait rigs and other techniques that allow fish time to swallow a hook. If a fish does swallow the hook, use pliers to cut the hook or line as short as possible.

Key Factor #2 – Physiological Stress

Stress can be defined as the combination of the fight a fish puts up prior to being landed, angler handing methods, and the amount of time spent out of the water.

Anglers can minimize the stress they cause by doing a few simple things. Using proper gear allows anglers to land their fish in a reasonable amount of time. Over-playing fish leads to exhaustion and higher instances of mortality. Landing the fish by hand, in a cradle, or in a shallow, rubber net is preferable to using a gaff (which causes a wound) or a net with rough mesh (which will remove protective slime and scales). Minimizing air exposure and handling time is also essential to minimize stress. Keep the fish in the water as much as you can while being careful to not touch or squeeze the gills. To understand how a fish feels out of water, try holding your breath while you unhook the fish and snap a photo. While taking that glory shot, it is very important to support the fish’s weight with both hands. Finally, resuscitating the fish before release will ensure maximum chances of survival. To resuscitate properly, hold the fish upright, in the swimming position so that water can flow through its mouth and out its gills. If you’re fishing a river, be sure to hold the fish facing into the current; when fishing through the ice, a quick head-first plunge into the hole will usually do the trick. Most fish will swim away, but it’s important to remember that any fish that dies after release is considered part of our possession limit.

As anglers, we all have a responsibility to help manage our fishing resources as responsibly as we can. There’s nothing wrong with bringing some fish home for the family, but we must be sure to put the big breeders back. By using artificial lures over live bait, targeting stocked fish whenever possible, and using proper landing, handling and release techniques, our fishing will continue to get better.