Simple changes to fishing gear and handling can greatly improve survival of released coho salmon

A recent study has revealed that simple modifications to fishing gear and handling techniques can significantly boost the survival rates of coho salmon that are released back into the ocean after being caught by recreational anglers. According to the research, conducted by scientists at the University of British Columbia’s Pacific Salmon Ecology and Conservation Laboratory, the method used to land and handle these fish plays a crucial role in determining their chances of surviving after release. This finding comes at a time when conservationists are increasingly focused on ensuring the sustainability of salmon populations, particularly in regions where catch-and-release practices are common. The study, published in the journal Fisheries Research, examined 235 adult coho salmon captured off the west coast of Vancouver Island. These fish were placed in seawater tanks for up to two weeks to monitor their survival rates under different conditions. The results showed that 96% of the fish with minimal or no dermal injury survived, compared to just 62% of those suffering from severe fin or scale damage. The primary source of this damage was identified as the use of standard “fish-friendly” mesh landing nets, which caused significant harm to the fish’s delicate skin and fins. Dr. Scott Hinch, one of the senior researchers leading the project, emphasized that the study highlights the importance of minimizing physical trauma during the capture process. He noted that even seemingly harmless actions, such as using certain types of hooks or improper handling techniques, can have lasting consequences on the fish’s ability to survive. For instance, the study found that tandem hooks, which are commonly used in angling, resulted in more severe injuries and made it harder to release the fish unharmed. The researchers recommended several practical steps for anglers aiming to increase the survival rate of released coho salmon. They advised keeping the fish in the water as much as possible during handling, avoiding the use of landing nets altogether, and instead using tools such as pliers or a release gaff to bring the fish alongside the boat. Additionally, they urged anglers to avoid using tandem or treble hooks, which contribute to greater injury and complicate the release process. The study also underscored the potential for delayed mortality among released fish. Many of the observed deaths occurred three to eight days after capture, indicating that traditional assessments based on 24-hour survival rates might severely underestimate the true impact of catch-and-release practices. Senior author Dr. Hinch explained that a fish might appear perfectly fine immediately after being released, only to succumb to injuries sustained during capture days later, an outcome often overlooked by anglers. These findings have already influenced changes in British Columbia’s fisheries regulations, particularly regarding the types of hooks permitted in certain areas. The research team pointed out that with hundreds of thousands of coho salmon being released annually along the province’s south coast, implementing these improved handling practices could enhance survival rates and provide valuable insights for fisheries management. By understanding how different handling methods affect fish survival, managers can better predict how many salmon will eventually return to spawn. The study marks the first experimental validation of handling recommendations previously proposed by the laboratory in 2024. While the current research does not directly measure long-term survival due to controlled laboratory conditions, it provides a clear framework for improving immediate outcomes. As the study continues to inform policy and practice, its implications extend beyond individual anglers to broader conservation strategies aimed at preserving salmon populations for future generations.