2019 Barkley Sound Chinook

[searun]

We turn in as many hatchery marked fish as possible to help DFO have better data on managing the fishery. One of the cool things is we get a nice summary back fairly quickly on those heads we turn in. This year we saw a lot of 3 year old Chinook in the mix. In fact it was the majority (6 out of 7 heads for Robertson Creek Hatchery). The number of 3 year olds caught in a fishery is a good indicator of the strength of the main run for the following year as most fish return as 4 year olds.

If our data is the same as others who turned in heads, and the bio-sampling at the hatchery this year, we could be looking at a fairly strong 2019 return to Barkley Sound (Robertson Hatchery fish).

Just wondering what other's on here got back from DFO as a mix of age class for Robertson fish? Curious, hoping others have observations or data they can share.

 

[Aces]

We turn in as many hatchery marked fish as possible to help DFO have better data on managing the fishery. One of the cool things is we get a nice summary back fairly quickly on those heads we turn in. This year we saw a lot of 3 year old Chinook in the mix. In fact it was the majority (6 out of 7 heads for Robertson Creek Hatchery). The number of 3 year olds caught in a fishery is a good indicator of the strength of the main run for the following year as most fish return as 4 year olds.

If our data is the same as others who turned in heads, and the bio-sampling at the hatchery this year, we could be looking at a fairly strong 2019 return to Barkley Sound (Robertson Hatchery fish).

Just wondering what other's on here got back from DFO as a mix of age class for Robertson fish? Curious, hoping others have observations or data they can share.

Same as you. 8/10 that had the wire were 3 yr olds for me. Hope that translates for a strong run of 4 yr olds in 2019

 

[searun]

Sure an interesting pattern. Going to dig into it a bit further. Chunky gave me a tip that perhaps there is a summary of the roll up data available already...quite interesting stuff. Sure shows the value of turning in our heads. I know its a pain, but the data can sure help better manage the fishery.

 

[Derby]

Same here .. the fish that had wire tags in there nose..3 year olds.. sure had a pile with no tags

 

[wildmanyeah]

Same here .. the fish that had wire tags in there nose..3 year olds.. sure had a pile with no tags

I had this same experience except in Vancouver/Nanaimo in April and May. I sent In a Few heads from Port Hardy In July but have not got a response back yet. The troubling thing tho and perhaps just luck was the lack of 15-20 ponders in April and May. In 2017 I had a few around 20 pounds that I suspect may have been 4 year olds or just nice big 3 year olds.





I don't have a big data set tho like you guides


This was posted by bonchovy at the start of this year looks like most of the heads they collected all year were 3 year olds. In 2017

 

[searun]

Good on ya for turning in your heads. Wish more people would follow your lead.

 

[kevind]

This is all fairly new to me but if last year it was a lot of 3 year old fish and this year it was a lot of 3 year old fish does that mean the 3 year old fish are going up to spawn and if not where are the 4 year old fish?

 

[searun]

Great question. General rule of thumb is that a particular brood year will have most of the fish return as 4 year olds. A portion will be 3 year old, 5 and some older...but most are 4 years. So if we see a strong number of 3 year old fish that can be an indicator of how well that particular brood year age class of fish did out in the ocean. The prior year showed a strong number of 3 year old fish, and the return overall was very good (above forecast). Hoping this is a good sign for next year. That said, there has been a lot of work done to raise some S-1 chinook, and the knock on them is they have been known to have an unusually high number or proportion that return as 3 year old...that could also be the case in the Barkley Sound fishery with the net pen, Nahmint and Sarita fish.

 

[searun]

Managed to get some further CWT data. Here's what I learned - still chewing on it

Sea Pen:

156 tags for 2018
24.4% are 4 year olds
72.4% are 3 year olds
3.2% are 5 year olds

Robertson Cr - S-0

0.7% are 2 yr olds
62% are 3 yr olds
32% are 4 yr olds
5.4% are 5 yr olds
0.3% are 6 yr olds

Nahmint:

85% are 3 yrs old
11% are 4 yrs old

Robertson Hatchery had a lot of trouble getting enough eggs this year. Little wonder with the low number of 4 yr fish. There were a lot of fish in the river - unfortunately most are 3 yr olds.

With the very strong stock composition being 3 yr old fish, that possibly signals that the 2015 brood year has experienced very good ocean survival - and the 4 yr olds unfortunately didn't.

Good news/bad news

 

[SerengetiGuide]

Wasn't the blob around in 2015 ? Makes you wonder that we essentially know nothing about salmon survival rates and it's a toss up every year it seems.

 

[Rob H]

Great question. General rule of thumb is that a particular brood year will have most of the fish return as 4 year olds. A portion will be 3 year old, 5 and some older...but most are 4 years. So if we see a strong number of 3 year old fish that can be an indicator of how well that particular brood year age class of fish did out in the ocean. The prior year showed a strong number of 3 year old fish, and the return overall was very good (above forecast). Hoping this is a good sign for next year. That said, there has been a lot of work done to raise some S-1 chinook, and the knock on them is they have been known to have an unusually high number or proportion that return as 3 year old...that could also be the case in the Barkley Sound fishery with the net pen, Nahmint and Sarita fish.

The Robertson Creek hatchery has lots of data on the returns to the hatchery for decades. The stock composition used to be approximately 20% 3 yr. fish, 60% 4 yr. fish, and 20% 5 yr. fish, with a small percentage returning as 6 yr. and older plus some 2 yr. male jacks. The problem with the 3 yr. old returners was that they were predominately male fish (80 to 90% if I can remember correctly). The 4 yr. fish were ~equal M/F and the 5 yr. fish were ~60%F. Therefore most of the eggs produced were from the 4 and 5 yr. old fish. It would be interesting to know the M/F distribution on the returning 3 yr. old fish this year.
The 3 yr. olds could indicate a strong return next year or they may just be part of the general return of younger fish coast wide (3 yr. fish instead of a majority as 4 yr. olds).
...Rob

 

[searun]

Yes, and if we are seeing a shift to 3 yr olds that is a major problem because the 3 year old females do not have the same fecundity as a 4 year old. I did see more very small females this year, so likely some could be 3 year olds. We call them Jills.

 

[wildmanyeah]

A Little bit off topic but still on topic of hatcheries and age.. Here is some recent data from the Capilano hatchery. I think the 1-2 year olds they call Jimmy's. Data from 2017, The column marked CN CAP is Chinook. I am also not sure if the Adult column contains 3 year olds, I will try and get some clarity on that.

 

[GDW]

Common sense would suggest that decades of retaining the biggest (oldest) fish and returning the smaller (youngest) fish would result in a population of smaller fish who spawn earlier.

I'm not sure the reason but I also think hatchery fish return at a younger age as well which compounds the problem.

I wouldn't expect a big run of 4 year olds next year.

 

[wildmanyeah]

Who knows, Here is some of the issues with respect to Fraser Chinook, Seems like 3 years returning now may be more of the norm then an indicator or strong runs.

 

[Whitebuck]

Perfect.....let’s keep the Fraser open for wall to wall gillnets from april till December!
This will help the stocks

 

[Christl Waters]

Word of the day: Fecundity
fe·cun·di·ty
NOUN

1. the ability to produce an abundance of offspring or new growth; fertility.
   "multiply mated females show increased fecundity" ·
   [more]
   "age-related decline in female fecundity"

New one for me, but I like it.

 

[wildmanyeah]

Just got some results back from I fish I caught this year in Port Hardy. It did not have a tag but someone caught one the next day in the same area and submitted the head. Looks like uncle sam's fish.

 

[wildmanyeah]

Bon chovy again was nice and shared their results on facebook

 

[searun]

Hmmm. Looks like more 3 year old fish. Wide spread pattern. Sure hope we see large returns of 4 year old fish in 2019 or this is a troubling sign.