Catch-and-release important to stocks

When we were kids, my father told us if we were not willing to clean the fish we caught ourselves, we had to put them back in the water

When we were kids, my father told us if we were not willing to clean the fish we caught ourselves, we had to put them back in the water unharmed.

He was an advocate of catch-and-release long before there was such a practice – in large part, I suspect, because he did not want to clean all the fish by himself. Be that as it may, catch-and-release is now widely practiced by an ever-increasing number of anglers.

Many North American salmon and trout waters have been designated catch-and-release fishing only in an attempt to preserve the quality of sport fishing. Catch-and-release is similarly promoted by governments as a management tool in an effort to reduce the cost of rearing and using stocked fish, while conservationists advocate catch-and-release as a way to ensure the sustainability of natural fish stocks.

The effects of catch-and-release on fish has been argued, studied, questioned and written about for the better part of the last 50 years. Countless studies have measured both the effects of various types of fishing tackle and angling techniques on fish mortality, and in pretty well every study, the link between the causes of fish mortality, the types of gear and techniques used to bring the fish in and subsequently release it, all boil down to one thing: the amount of stress fish are subjected to directly affects post-release survival rates.

Although catch-and-release mortality data may not necessarily show, statistically, a direct correlation between the degree of physiological stress and fish mortality in the wild, one particular experiment (by Ferguson and Tufts) did examine the effects of artificially induced stress on rainbow trout in a tank. The study concluded that various forms of physiological stress do directly contribute to fish mortality and that, by inference, a minimization of stress would effectively reduce catch-and-release mortality rates of fish in the wild.

To put things in simple terms, the manner in which fish are caught is important.

Numerous studies have compared mortality rates and angling methods, and have found the use of artificial baits such as lures or flies, does significantly reduce both the incidence of fish swallowing bait too deeply to remove the hook without injury, and the rate of fish mortality. A majority of fish mortality studies would also seem to indicate the physiological effects of stress (as a result of being caught) are usually pretty well reversed within a 24-hour period. It can be inferred from these studies that the use of heavy tackle is desirable in lowering mortality rates and, conversely, lighter tackle and lower strength lines may increase the risk of mortality.

Common sense, as well as scientific data, show the longer fish are out of the water, the more they become stressed, and that a minimal amount of handling not only reduces the amount of post-catch stress but also the risk of physical injury due to struggling and loss of body slime. Holding fish out of the water puts added stress on a fish’s inner body and organs which are, in part, held in place by the external force of water pressure.

I try to keep a fish right on the surface, but still in the water, when removing the hook.

Prior to release, any fish displaying signs of exhaustion or stress should be resuscitated by holding the fish with its head pointing into the current. (In still waters, fish can be moved back-and-forth in a figure-eight pattern to increase the amount of oxygenated water passing through the gills.) When the fish demonstrates a stable equilibrium and strong swimming ability, it can be safely released.

The way I see it, proper catch-and-release practices are important not only to the survival fish that are caught, but also to the future of fish stocks to be caught in years to come.