Northern Bulls

[chrome/22]

So some locally famous watersheds about 2-3 hours north of my little stronghold here in NW Montana hold some outstanding bulls. Some of the creeks feeding into the river generate the ice cold/clear water bull trout thrive in.

While doing 2 months pre & 4 months post of physical therapy on a repaired L shoulder one of the therapist would taunt me with pic after pic of his fly rod summer/fall exploits on said watershed. I started daydreaming

My question... if this river stream system was magically moved to say north Vancouver Island with access to saltwater how long would it take for these magnum bulls to migrate out?

c/22

 

[Paige]

They might be there already!

 

[Matt B]

They could get to salt already if they weren’t so damn lazy. Just swim downstream and keep swimmin’!

It’s the getting back home part that will be difficult for them.

 

[Pink Nighty]

They could get to salt already if they weren’t so damn lazy. Just swim downstream and keep swimmin’!

It’s the getting back home part that will be difficult for them.

I've often wondered what pre-hydro Columbia/snake bulls set as boundaries to anadromy. For that matter, do bulls in the upper but anadromous accessible Fraser go to the sea?

Probably, if they feel like it. #bullshit

 

[chrome/22]

I guess the best real-life example of my fictional scenario would be the the Elwha dam removal that happened 2011-2014. The long captive native adronimous steelhead trout in the genes of those up water fish was again free to express itself, while other types possibly came scouting in from the local saltwater side.

 

[Pink Nighty]

I guess the best real-life example of my fictional scenario would be the the Elwha dam removal that happened 2011-2014. The long captive native adronimous steelhead trout in the genes of those up water fish was again free to express itself, while other types possibly came scouting in from the local saltwater side.

I see that, and I wonder too. But Alberta is one hell of a lot further from the salt than the upper elwha!

 

[Wanative]

I've often wondered what pre-hydro Columbia/snake bulls set as boundaries to anadromy. For that matter, do bulls in the upper but anadromous accessible Fraser go to the sea?

Probably, if they feel like it. #bullshit

They do.

 

[Robert Engleheart]

I've often wondered what pre-hydro Columbia/snake bulls set as boundaries to anadromy. For that matter, do bulls in the upper but anadromous accessible Fraser go to the sea?

Probably, if they feel like it. #bullshit

I’ve seen pictures of BIG bull trout from upper Fraser that were said to be anadromous.

 

[Chris Bellows]

I’ve seen pictures of BIG bull trout from upper Fraser that were said to be anadromous.

Hard to imagine big bull trout from the upper Fraser wouldn't have gotten that big from eating all of the salmon based food from the upper Fraser (fry, eggs, and flesh) than making the effort to travel all the way to the estuary and then back up through the canyon.

 

[doublespey]

Paging Curt Kramer Seriously tho, Chrome/22's hypothetical example was focused on if you moved inland bulls into a salt migration friendly habitat (like an upper Vancouver Island river). My guess from having chased Bulls?Dollys around fresh (infrequently) and saltwater (even less) is that, being the prey-centric and highly migratory, once the given population of bulls maxxed out the available food source some would begin migrating to find more food. Coastal rivers, with their regular flooding and comparative lack of nutrients, would inspire that behavior rather quickly once the salmon carcasses and eggs ran out.

 

[Smalma]

In the case of the Skagit bull trout, it appears that while they spawn in the upper reaches of the basin (where winter stream temperatures are below 4 degree C (below 49 degrees F) they tend to fill the rearing habitat from those spawning areas downstream. At low abundances nearly all the juvenile production remains in those headwaters. As their abundances increase some of those juveniles move downstream to take advance of additional forage and rearing habitats becoming fluvial fish. As that rearing space and forage become limited more and more of the fish continue downstream to take up anadromous life history.

How quickly a new population adopts life history could largely depend on amount of freshwater rearing and forage available.

As it happens not too long ago a read a bull trout paper where the study area was the upper Fraser above Prince George (UFW) where radio tagged fish movements were monitored. Tracking the fish from spawning and forage areas. Reread the paper this morning and the authors referred to those UFW bull trout as fluvial fish. To Chris's point those foraging areas were where there was abundant salmon. In the capture process to collect fish for the radio tags there were 3 mortalities. One of those fish had eaten 44 salmonid juveniles, one 20 and the third none.

Found the some of the differences between those UFW bulls and our Skagit fish interesting. While the Skagit typically spawn from mid-October to early November those UFW spawned over a 3-week period starting in early September. The Skagit fish once reaching sexual maturity tend to spawn annually. The UFW fish once reaching maturity would spawn every second or third years. Those differences are likely due different stream temperature profiles and habitat. In spite of those differences the fish's behaviors were very similar exhibiting complex migration and feeding behaviors.

As an aside the largest fish collected in that UFW study was nearly 34 inches long and weighted about 12 #s. Not a lot different than that were seen on the Skagit.

As always the more a learn about these critters the more interesting they become.

Curt