Over the past several years, I’ve had the good fortune of being hired by various agencies to catch — with rod and reel — Chinook salmon for acoustic tagging studies. These have all been tracking programs to look at the spatial and temporal distribution of both spring and fall kings…but some very interesting anecdotal information has come out as well.
Some of the most compelling stuff had to do with the relationship between hook placement in a fish and its chance for survival.
As I started reflecting on some of my experiences, I got on the horn with noted Northwest guide and fellow “science angler” Bob Toman, who has done even more salmon tagging than I in Oregon. As always, he was extremely interesting talk to and had a lot of info to share as well.
So, here are just some random observations from our experiences – ones that I think may surprise you a bit…
If it Bleeds it Dies??
One of the longstanding beliefs I’ve held onto over the years is that a salmon or steelhead is likely going to die if it is pumping blood from its gills. Might as well bonk it, right? Well, not so fast…
After tagging hundreds of Chinook on the Yuba and Feather rivers in Northern California, I’ve had a handful of our fish hooked deep in the gill arches (mostly hooked on No. 4 & 5 spinners) -– all of which I figured were dead. A couple did die, but we also had several amazing stories of survival.
The most blatant example came one October while targeting fall kings on the Yuba. A dusky buck of nearly 30 pounds mashed my Kwikfish and took it down deep…way deep. When we got the fish to the boat, the K15 was barely visible in its mouth. It quickly became obvious that the fish had a severed gill arch as it was pumping an alarming amount of blood.
Fishing had been slow so far that week, so the biologists decided to outfit the king with an acoustic tag anyway. While they tagged and measured the salmon, I constantly scooped blood out of the livewell with a 5-gallon bucket and replaced it with fresh water. The buck was bleeding so heavily that I couldn’t keep the water clean and soon he was obscured by crimson in the tank.
When we released the big boy, we watched as he swam weakly off in a daze and figured he’d be buzzard food by morning. Well, a couple weeks later, the biologist texted me and said that she found our fish, dubbed “The Bleeder,” many miles upstream and hanging with a female on a redd!
Toman has had similar experiences with spring Chinook on the Willamette River. He said that 150 springers that he caught and tagged one session were released into a fish ladder so they could be monitored. Of that batch, a little over a dozen of the fish had been hooked in the gill arches and were bleeders. After their release, several of the wounded Chinook drifted upside down and were barely quivering against the back screen of the pen. The biologist figured those kings were going to die and almost pulled them from the pen to toss them downstream. But he decided not to and was blown away to see that the fish had righted themselves later and eventually all survived to swim out on their own.
The Ability to Heal
“Salmon have blood pressure just like you and I do,” says Toman. “When you make them bleed, the pressure drops off a bit and then they can often plug the hole and stop the blood loss. Eventually, their bodies remanufacture more blood and they can continue on.”
I had never thought about that – the fact that a fish can sustain a potentially mortal wound and then sometimes heal itself — but Toman’s point really makes sense.
“You see those fish with big seal, shark or killer whale bites and you know they must have been bleeding like a stuck pig when it first happened,” he says. “But, again, they are able to heal themselves and the lost blood gets replaced.”
Toman concedes, however, that mortality was as high as 83 percent on his springers when hooked in the gills. During his study years, there was a 60 percent mortality rate for gut-hooked fish. The most impressive and encouraging stat, however, was that just 2.3 percent of the fish Toman hooked in the jaw died on his projects.
To support that evidence, I tagged 114 spring Chinook on the Yuba a few years back. When hired later that year to catch Fall-Run, I actually recaptured 5 of my springers! Pretty amazing when you consider it was 4 months later when I caught them again! Of those 5 re-captures, all were jaw hooked the first time and two were gill hooked the second time. All five “two timers” were later tracked upstream in the spawning areas.
Toman says that the “official number” assigned to catch and release mortality of springers in Oregon is 12 percent overall, but that seems a bit high and he has been asking survey crews to ask anglers where their fish were hooked to try to gain more data about hook placement.
I think info like that is important for fisheries managers to consider when looking at quotas and regulations for rivers that have both hatchery and wild fish in them. Obviously, we want to keep angling opportunities available while minimizing any damage to the native spawner population. Some of that can be accomplished with catch & release and gear-specific regs. ?
We’ve already looked at mortality rates of spring Chinook based on hook placement and Toman thinks that data too could be used as a management tool to increase survival of released fish.
“One thing I’ve noticed is when we fished prawns straight or with a Corkie, the springers routinely swallowed them,” says Toman. “But when we rigged prawns with spinners, the fish hit them like a lure and were almost always hooked in the jaw – about 90 percent were like that. Though I get nowhere at all with it, I’ve been suggesting the managers look at maybe making some regulations that would reduce the incidence of gut-hooked fish. If you could use only, say, a prawn spinner on the Columbia, we could keep that mortality rate down around that 2.3 percent rather than the 12 percent they say it is. It would be a great tool for us because we would get to fish a whole lot longer.”
Speaking of gear changes, Toman says that he feels that there are several situations in which the mandatory use of larger hooks would also help because he believes they keep fish from swallowing the bait.
“We did a lot of underwater filming in Alaska, watching kings bite eggs,” he says. “A 2/0, 3/0 or even 4/0 hook can get swallowed pretty deep — but with big 5/0 and 6/0’s on there, a fish feels them pretty quickly and starts shaking his head rather than continuing to swallow. Then you hook ‘em in the mouth more often than the gills or gut.”
Of course, there are other things to consider – trebels or singles; how long a fish is played; how it is handled, water temps, etc., but Toman makes some interesting points here.
Food for thought anyway…