Catch and release fishing is a widely practiced approach in recreational angling, where fish are returned to the water immediately after being caught. This method promotes sustainability for various species. A key question for anglers and conservationists is whether fish truly survive this encounter or if the act itself leads to significant post-release mortality.
Causes of Mortality After Release
Fish released after being caught can experience mortality due to several biological and physical factors. Physical trauma from hooks can cause death. Hooks deeply embedded in vital organs like gills or the gut can lead to severe damage and bleeding, impacting survival more significantly than mouth-hooking.
Physiological stress also plays a role in post-release mortality. The struggle during capture causes an increase in stress hormones and a buildup of lactic acid in the fish’s blood and tissues, similar to intense exercise in humans. This physiological disturbance can deplete oxygen reserves and impair normal bodily functions. Even if a fish appears to swim away, this stress can result in delayed mortality, making them more vulnerable to disease or predation.
Factors Affecting Fish Survival
Fish survival after release is influenced by several variables. Water temperature is a significant environmental factor, with warmer temperatures often leading to higher mortality rates, particularly for cold-water species like trout and salmon. Warmer water holds less dissolved oxygen, which exacerbates the stress of capture and makes recovery more challenging for the fish.
Species also determines survival rates, as some are more sensitive to handling and stress. Deep-water fish, for instance, often suffer from barotrauma when brought to the surface quickly, causing their swim bladders to expand due to pressure changes. Symptoms can include bulging eyes or a protruding stomach, and this condition can make it difficult for the fish to swim back to depth, increasing their risk of death. The type of fishing gear used, such as barbless hooks or circle hooks, can reduce injury and improve survival compared to traditional J-hooks or barbed hooks.
Strategies to Maximize Fish Survival
Anglers can enhance the survival of released fish through several strategies. Selecting appropriate tackle, such as barbless hooks or crimping barbs, minimizes injury and facilitates easier hook removal. Using tackle strong enough to land the fish quickly reduces the duration of the fight, lessening the fish’s exhaustion and stress.
Proper handling techniques are important; anglers should wet their hands before touching fish to protect their slime coat. Keeping the fish in the water as much as possible and avoiding air exposure, ideally for less than 60 seconds, significantly improves survival rates. When a fish must be removed for dehooking or a quick photograph, supporting its entire body horizontally, rather than vertically by the mouth or gills, helps prevent internal damage.
Using dehooking tools aids in quick and careful hook removal, often allowing the fish to remain in the water. If a fish has swallowed the hook deeply, cutting the line as close to the hook as possible is often preferable to attempting to remove it, as the hook may eventually corrode or be expelled. For fish caught from deep water exhibiting signs of barotrauma, using descending devices or venting tools can help them return to depth and recompress their swim bladder. Anglers should revive sluggish fish by gently holding them upright in the water, facing into the current, until they regain strength and swim away.
Catch and Release in Conservation
Catch and release fishing serves as a management tool in fisheries, contributing to population sustainability and ethical angling practices. It allows for recreational fishing pressure while reducing the overall impact on fish stocks. This method is useful for species that grow slowly or have conservation concerns, helping to maintain healthy breeding populations.
While some mortality occurs after release, this rate is lower than if all caught fish were kept. The practice supports respecting wildlife and acting as stewards of aquatic ecosystems. Through catch and release, anglers contribute to long-term fish population health, ensuring future generations can enjoy fishing experiences.