New Pacific salmon research is encouraging anglers to rethink the way they practise catch-and-release

Photo: Katie Zinn

HANDLE WITH CARE

In developing the 15 best practices for catch-and-release, Scott Hinch and his research team from the Pacific Salmon Ecology and Conservation Laboratory focused on three main areas: avoiding small fish, modifying gear and tactics, and minimizing contact. They also covered a broad range of angling behaviour, including hook size choices, trolling techniques, fishing strategies, net use and, especially, fish handling.

Overall, the research showed the mortality rate for fish released in good condition was less than 10 per cent for chinook salmon and closer to 20 per cent for coho. Hinch says he figures the difference is because coho tend to feed at deeper depths and roll around more when fighting, leading to more injuries.

Their smaller size probably also played a part. The study found that smaller fish of both salmon species take longer to recover after capture, and are more likely to suffer hook injuries. “Eye injuries, in particular, are a death sentence, but not right away,” says Hinch, noting the mortality rate for chinook with eye injuries, even when the damage didn’t look terrible, was above 40 per cent.

The recommendations focus on three main areas: avoiding small fish, modifying gear and tactics, and minimizing contact

Using smaller hooks could help eliminate some injuries, the study concluded, although the best option would be to avoid catching small fish altogether by changing depths or location.

Another recommended change in fishing tactics is to ditch in-line flashers and attach them to the downrigger instead. Comparing the respiration rates of fish caught with and without inline flashers, the researchers found the fish worked a lot harder and took longer to recover after fighting an in-line flasher. Says Hinch: “We know that if the fish is not fully recovered, it will not escape predators as well.”

Perhaps the biggest take away from the research, though, is that marine salmon are fragile, and any handling is detrimental

Perhaps the biggest take away from the research, though, is that marine salmon are fragile, and any handling is detrimental. Even fish-friendly landing nets can cut and damage fins, for example, while simply touching fish can remove scales and lead to bruising—the researchers found fingerprints on some study fish weeks after their capture.

Having established a direct connection between the amount of handling and mortality, the researchers concluded the best practice for any fish that will be released is to not use a net, avoid touching and forgo any revival efforts. When they did just that in their study, chinook mortality fell to near zero.

According to Hinch and his team, the following 15 recommendations offer the best approach to ensuring released chinook and coho survive.

1. Use smaller hook sizes

2. Avoid treblehooks

3. Avoid tandem hook point set-ups

4. Avoid flashers

5. Land fish as quickly as possible

6. Avoid air exposure

7. Avoid using landing nets

8. Limit touching of fish

9. Handle fish with wet hands

10. Release fish at the water line

11. Release fish immediately

12. Avoid small fish

13. Avoid fishing locations if predators are present

14. Avoid catch-and-release when surfaces waters are at or above 18°C

15. Lessen your interactions

For complete details on each best practice, go to www.sportfishing.bc.ca.