UBC Researchers studying impacts of catch-and-release methods (above) in sports fishing have come up with 15 tips to increase salmon survival.UBC Researchers studying impacts of catch-and-release methods (above) in sports fishing have come up with 15 tips to increase salmon survival.

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Sport fishers and scientists are launching a bid to improve salmon survival by changing recommended catch-and-release techniques.

The Sport Fishing Institute (SFI) is “fully on board” with 15 new guidelines developed after a University of British Columbia study determined injuries from specific hooks, net use and handling are key factors driving fish mortality of threatened chinook or coho salmon, said SFI executive director Owen Bird. 

Sport fishers are likely to adopt any measures that give fish a fighting chance, Bird said. 

“Respecting the fish is very much a part of the experience, so it's a pretty easy pitch to sell to anglers,” Bird said. 

The tidal and freshwater sports fishing sectors combined contribute approximately $1 billion to the economy and employed 9,000 people in B.C, in 2022, according to federal studies. 

Researchers identified what harmed fish the most by tagging 1,500 salmon caught by anglers with acoustic transmitters, said Scott Hinch, who heads the UBC Pacific Salmon Ecology and Conservation Lab team that did the six-year study.

Once the fish were released, researchers tracked them over time through a network of underwater receiver systems in the Salish Sea. 

The estimated mortality rate for released chinook can reach up to 40 per cent depending on the fishing tactics, gear, and injuries from over-handling, the study found. 

“We looked at different types of hooks, different types of gear, different types of landing nets, different amounts of handling and looked at all of the injuries and other consequences that a fish appeared to have when they came into the boat,” Hinch said.

Eye injuries caused by large hooks topped the list, he noted. 

“When a fish bites a hook too big for the body size, it comes through the mouth into the eye.” 

Chinook salmon with an eye injury were 20 per cent more likely to die within 10 days after release. Most uninjured fish lived, he said. 

Using small hooks and avoiding flashers — a flat shiny lure which increases the energy demands on a fish during its fight on the line and slows its recovery on release — improves survival, the study determined. 

Landing nets are also not fish-friendly, Hinch said. They easily damage fragile fins,  scales and the protective mucus on salmons’ bodies, injuries that also impact fish mortality by up to 20 per cent. 

It’s best to release a hooked salmon without the use of a net at the waterline, which also eliminates a fish’s exposure to air which also drives down survival. If a net must be used, leaving it loose and in the water will reduce the impact to fish, Hinch noted. 

People should avoid handling fish, but if necessary, they should ensure their hands are wet and work as rapidly and gently as possible, he added. 

Coho are significantly less resilient than chinook following a catch-and-release — although more research is needed as to why, the study found. Even when returned to the ocean in good condition, Coho salmon suffered a 17 per cent mortality rate over a couple of days. 

Smaller chinook and coho were also significantly more likely to die than larger fish, the study found. As well, warm ocean temperatures diminish salmon survival rates after the stress of being caught, the study noted. 

Anglers should avoid catch-and-release when surface ocean temperatures are higher than 18 C. They should also move to a different area, fish at a different depth, and increase lure sizes if they are catching small salmon. 

The SFI assisted researchers by connecting them with recreational fishers and lodges to get them onto boats to gather data for the study, along with facilitating an angler survey, Bird said. 

Now, the institute will promote the new catch-and-release methods through instructional videos, social media, links to the research, and the "Release Them Right" campaign, he said. 

Many sports fishers already follow some of the recommended guidelines, as well as opting to release bigger fish “to live another day” rather than take them home as trophies even if regulations permit it. 

Anglers are also encouraged to rethink their “look what I caught photos” and leave fish in the water when documenting their catch, Bird said.  

Legally retained fish headed to the barbecue make for excellent fish photos and reflect the excitement of fishing, he said. 

“We should probably look for a different kind of photo as we move forward, knowing what we know now.” 

— This article was originally published by Canada's National Observer

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