Some of the penninsula rivers have as a requirement the measuring of a steelhead's dorsal fin to tell if it is of hatchery origin or not. The national park regs note a dorsal height of less than 2 1/8 " (credit card width) as a hatchery fish.

I have always measured the rear of the dorsal from the back to the tip of the fin with the fin AT REST. A friend disagrees, saying the fin must be fully extended and THEN measured.

The regs make no mention of extending the fin before measuring so who's right?

When that rule was a state regulation in 1984, the measurement was made with the dorsal fin extended. That's the only way that makes sense to me. "At rest" could yield several conflicting measurements, making such a rule useless, not that I'm saying such a rule is perfectly useful, either. But it's more enforceable, that is, the fin either measures 2 1/8" or it doesn't, as opposed to the more subjective interpretation of when is a fin a stubbed dorsal fin or not. I think the subjective interpretation could easily be in the high 90s percent accurate, but it's less effective as an enforcement rule. I presume that's why the NPS chose the credit card rule.

Sincerely,

Salmo g.

you really don't even need a measurement tool to figure it out. If the spines on the dorsal are perfectly straight, not mangled or curved, then chances are it's a native fish. I personally think that they should lower the height requirement to 1 and 3/4 or something similar. There have been a lot of native steelhead bonked within the national park due to that rule.

I've alway's measured from the most forward part of the fin fully extended.That is how Mark & Kieth did the measuring when we were checked a couple years ago.They are the park rangers.I agree with this hieght thing being to long it should fall some where between 2" &
1 3/4".If they would just make 100% fin clipping mandatory in the native & other hatcheries we wouldn't be having this topic.
Good luck,
STRIKE ZONE

cutthroat,

I don't normally need a measurement tool either to determine a hatchery fish. I'm well versed in what a deformed hatchery dorsal looks like. The problem is I have caught a number cookie cutter tribal hatchery fish that had perfect dorsals that pushed the threshold of the measurement limit. Due to the location caught, I am 95% certain these are hatchery fish.

I'm not implying I want to push the the limit and potentially keep a wild fish under the disguise of a hatchery fish. I don't. I wouldn't have a problem at all with them shortening the measurement. It would solve the problem if all the fish were clipped but they aren't and, I suspect, won't be anytime soon. For whatever reason,this particular tribe generates smolts under rearing conditions that have little to no effect on the dorsal.

I only started this post because the winter season is at our doorstep and I don't like the idea of squirming with the possibility of a fine if mr. park ranger arrives to check the catch. I just want to know I am measuring correctly and if I have measured in error the last few years.

Eric,
I've got a hunch about the river you are talking about I too, am getting a little excited. Clipping all hatchery fish would certainly solve the problem. However, better safe than sorry. You never know what side of the bed Mr. Park Ranger woke up on. Personally, I'd never do anything that could potentially get my fishing privilages revoked. Use the credit card and you should be fine.
Cuttie

Oh yeah, it's when the fin is extended. 100% sure on that one.

cut,

Your hunch of the river is probably correct

Thanks for the dialogue.