A Different Twist in the SRKW/Chinook Saga

Posted by: RUNnGUN

A Different Twist in the SRKW/Chinook Saga - 12/16/19 05:43 PM

https://www.knkx.org/post/northern-resid...largest-chinook

Hmm. Healthy Northern Orca populations could be eating up the biggest Chinook.
Posted by: FleaFlickr02

Re: A Different Twist in the SRKW/Chinook Saga - 12/16/19 10:14 PM

Yeah, no... Pretty sure we're the ones shrinking the salmon and starving the SRKWs.

It's not how many we take out of the ocean each year; it's how many years it takes the ocean to grow a 30-lb. King. 4 or more commercial and rec seasons, even at "reduced" quotas, are gonna take a monster bite out of the longer life histories.
Posted by: Salmo g.

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 08:54 AM

I find it dubious that their study finds that commercial fishing hasn't led to smaller average size among Chinook salmon. On the other hand, it's obvious that those northern resident killer whales are low-holin' low lifes for depriving their southern cousins of the Chinook they need.
Posted by: Bay wolf

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 09:13 AM

Originally Posted By: Salmo g.
... On the other hand, it's obvious that those northern resident killer whales are low-holin' low lifes for depriving their southern cousins of the Chinook they need.


Salmo,

Are you referring to the NRKW or the Northern Resident Commercial Fishermen as the "Low-holin' low lifes? LOL!
Posted by: Todd

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 09:56 AM

It makes sense to me that the longer a fish stays in the ocean, the longer it is likely to be eaten by something in that ocean...whether that "something" is a whale, recreational fisher, commercial fisher, or Cthulu.

That being said...somehow salmon managed to be large and numerous, and managed it in the presence of whales...it's the addition of humans that have completely fuckked them and most every other animal on this planet, excepting maybe coyotes, rats, and cockroaches.

Fish on...

Todd
Posted by: cohoangler

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 10:18 AM

I agree with Salmo g.

It is really hard to believe they could honestly find that commercial fishing is blameless. This is particularly startling given the high levels of by-catch among the trawl fleet.

To blame NRKW’s seems to ignore the fact that they have been living in the GoA for thousands of years. But only now they are eating large Chinook?! What changed?

Did the NRKW suddenly develop a taste for large Chinook? Did they recently take up residence where they happen to find lots of Chinook that originate in the Columbia River? Or did the Columbia River Chinook change their migratory patterns such that they now swim past where the NRKW are eating?

If they are going to blame NRKW, the scientists need to explain how NRKW weren’t feeding on large Chinook in the past, but suddenly are now.

The conclusion borders on preposterous.
Posted by: Carcassman

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 10:20 AM

Sure the NRKWs are eating Chinook but I suspect that they will be hitting Yukon, Kenai, and other AK rivers more than ours. Unless, of course, AK hammers their Chinook and the NRKWs need to find other sources.
Posted by: Todd

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 10:32 AM

"Predator Control" is almost never an issue until there aren't enough prey critters to satiate our human need to overharvest...then it's time to limit all the other predators, even the ones that barely register on the scale compared to our predation.

Sure,1000 fish are in a run and we harvest 999 and then when a sea lion eats the last one we can yell "Look! That sea lion made salmon extinct!"...and we'd be right...just really really wrong while being right.

Fish on...

Todd
Posted by: Bay wolf

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 10:34 AM

Perhaps it’s like everything else in the present culture. Say it enough and loud enough and it becomes fact, regardless of how ridicules.

Combine the culture of political fish management where harvest at all cost is priority over conservation and preservation and it’s simple to see that without a dramatic paradigm shift, all is lost. And the complete collapse of the fishery is probably going to be that shift.
Posted by: Larry B

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 10:49 AM

Originally Posted By: cohoangler
I agree with Salmo g.

It is really hard to believe they could honestly find that commercial fishing is blameless. This is particularly startling given the high levels of by-catch among the trawl fleet.

To blame NRKW’s seems to ignore the fact that they have been living in the GoA for thousands of years. But only now they are eating large Chinook?! What changed?

Did the NRKW suddenly develop a taste for large Chinook? Did they recently take up residence where they happen to find lots of Chinook that originate in the Columbia River? Or did the Columbia River Chinook change their migratory patterns such that they now swim past where the NRKW are eating?

If they are going to blame NRKW, the scientists need to explain how NRKW weren’t feeding on large Chinook in the past, but suddenly are now.

The conclusion borders on preposterous.


Preposterous? If one is to believe the numbers a 3X increase in NRKW over the last 40 years is significant in terms of predation targeting larger prey and resulting impact on SRKW. Looking more closely at the article they report that the number of NRKW now in the Salish Sea is put at 200 and continues to grow. Clearly something is going right for them.

Is selective predation by NRKW the only factor? Certainly not nor did I read anything in the article which made such a conclusion.
Posted by: Smalma

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 11:01 AM

I actually took the time to read the report and while it is hard to fault some of the findings it does present only part of the issue.

Some background: Chinook salmon evolved to advantage of freshwater habitat features over that used by other salmonids. Chinook are mostly large river fish that evolved to successfully use that habitat including spawning in very large substrate. That success required a large body size which historically they did in spades! Most of our rivers have fish that were normally 30 and 40#s with nice mix of even larger fish with some rivers (Elwha, Columbia, etc.) producing fish over 100#.

Orcas are large animals that over time learned to take advantage of those large Chinook as a food source. Remember that an adult orca might require 450# of fish day. They are designed to eat larger animals; the transient orcas regularly feed on adult harbor seals and the oceanic orcas have learned to kill great white sharks. Those resident orcas who are fish eaters have shown a strong preference for large body Chinook (fewer fish to catch with less energy spent). One study that I read showed that orcas where 6 times more likely to take a 5 year old Chinook over a 4 year old more than 45 times more likely than a 3 years.

What the report found was that even with decreased fishing the over size of the Chinook declined as the northern resident orcas increased. That result is hardly surprising as the it is clear that compared to the historical size distribution today's are significantly smaller with lot fewer larger Chinook with those that might be considered larger much smaller than in the past. Clearly to feed a given population under that situation the overall exploitation rate on the so-called larger Chinook on the over Chinook populations has to increase. It takes ever increasing portion of the Chinook population to supply the needed biomass to feed them which only gets worst as the number of orcas. I find in unfair to blame the size decline on the Chinook as the whole mess has been largely driven by man's actions.

The average Chinook is declining because of ocean fisheries (largely hook and line) are selectively harvesting the faster growing and longer lived individuals in the population. Those impacts continue. Gill net fisheries (both tribal and non-treaty also exert selective pressure on the Puget Sound size and those continue today. Even though over all fishing exploitation rates have declined it remains the case that smaller fish are more likely to survive to contribute to the next generation.

Fishing is only one aspect of driving us to smaller Chinook. Habitat alterations have also dramatic the habitats that once were favorable to Chinook. Examples of those habitat changes include truncation of river lengths, decrease size of the stream bed substrate (no long need to be large females to construct their redds), stream bed instability, etc. Again these new conditions not only continue they continue to get worst leading to continued shrinking Chinook.

Hatcheries themselves also are playing an important role in the shrinking of our Chinook. Adult size and age at spawning experience different selection pressures in the wild than a hatchery (less benefit from being a large fish in the hatchery). The combination of the fishery selection on each hatchery generation assure that the fish escape fisheries are younger/smaller than their parents. To date little effort has been made at the hatcheries to establish spawning protocols that might reverse some the size selective being exert while the fish are at sea. Currently the spawning protocol is take the returning the adults randomly. The combination the spawning protocols and fishing has result in increased numbers of jacks (2 year old males) in the hatchery spawning population. Younger fish in the breeding population results in younger and smaller Chinook.

The smaller hatchery fish and river habitat problems are intersecting in many of PS rivers. In some of the rivers; especially those relying on the Green river fall stock hatchery fish contribute a significant portion of the natural spawning population. For example over a 5 year periods (2014 to 2018) on the Cedar river 30% of the natural spawners where hatchery fish, on the Nisqually 32% were hatchery fish, on the Puyallup 66% were hatchery fish, on the Green 74% were hatchery fish and on the Skokomish 96%were hatchery fish. Those high contribution rates of shrinking hatchery Chinook are passing on that tendency to the wild populations.

The big question given what is presented in the citied and all the above can the shrinking Chinook size and the corresponding impacts on the resident orcas be reverse? Or perhaps of even more importance do we as society even want to address the issue?

Curt
Posted by: cohoangler

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 12:23 PM

A couple responses:

Larry B - I understand your point. However, Todd’s response is exactly correct. If we harvest 99 fish out of 100, and marine mammals take the last one, we blame the marine mammals for the resulting extinction. That is what is happening here. I don’t doubt that NRKW are taking more Chinook than we’d like them to, but if there were more large Chinook, there would be more for the SRKW’s.

Smalma – Agree almost entirely with your post.

However, I’m not sure that gill nets in Puget Sound can result in smaller size at maturity. For the most part, gill nets are deployed in or near the home river. That being the case, the fish that are returning have already reached their terminal body size. They ain’t getting any bigger. They’ve done all the growing they’re going to do. Not so for harvest in the open ocean. Any salmon that is still in the feeding/growing stages along the coast (or in PS) will continue to grow until it’s caught or eaten, or begins their trek back home.

So commercial/recreational trolling for Chinook while they’re in their feeding phase will contribute directly to a smaller size at maturity of the surviving adults. Terminal harvest, by whatever means, does not contribute directly to smaller size at maturity.
Posted by: Smalma

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 01:34 PM

cohoangler-
I agree that the terminal gill net fisheries are largely terminal area fisheries with the adult Chinook likely at full maturity size. However my concern was and remains that the typically PS Chinook gill net with a 7 1/4 inch mess net is most efficient at catching fish in that 10 to 16 # and less efficient at capturing the smaller fish (3 year-olds and jacks). As a result the fish that escape the gill net fishery are potentially on the average younger and smaller than those were caught.

I think the case of the hatchery jacks makes that case clearly. The vast majority of the jacks today are less than 22 inches long and most of which easily swim through those Chinook gill net meshes thus skewing the size distribution of the fish escaping the fishery. I believe that historically your thinking about the selectivity of the gill nets during the Chinook fisheries was largely correct but as the size distribution of PS Chinook decreases that target size of those nets remain the same but the size of the target fish has decreased thus more selectivity.

Curt
Posted by: Carcassman

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 02:35 PM

Gillnets are very size selective, that is why the can work. Or fail. I understand that back in the 30s and 40s Chinook gear for rivers like the Skagit was over 8". Smaller fish, smaller web, like Smalma says.

There was an interesting situation of the Skagit in the 80s wherein coho needed protection. So, commercial fisheries for chum fished larger gear. It was over 6, maybe 6.5. Anyway, the netters (I and NI) got lots of chum and few, as in one or two, coho. Then, December came and management switched to steelhead. Smaller mesh and all sorts of coho were now showing up.

Bill Ricker noted that gill nets, sometimes, removed the smaller fish and left the larger. This occurred, in the fisheries he looked at, where sockeye were targeted and chum incidental. Small chum taken, what's left was larger.

There are a lot of balls in play and managers are often hard pressed to keep an eye on more than a few. Plus, the data is all "in the Past". It will take a couple of years, maybe a cycle or two, to see a trend well and then you layer onto that PDO and such.
Posted by: Smalma

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 03:03 PM

CM -
Old reports indicate that a century ago the standard Chinook gear in a lower Skagit spring Chinook fishery was a gill net with a 9 1/2 mesh. Don't know what the average size of Chinook caught in such a net but guessing in was in the neighborhood of 30#.

Curt
Posted by: Carcassman

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 04:33 PM

Yeah, we have lost a whole lot of "size". I would think they had to be larger as the 7.5 gets some 25+ mind chum, but maybe their teeth snag.

Do know that whatever they were using for springers in the Big C in the 80s got quite a few 20+ steelhead.
Posted by: darth baiter

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 06:46 PM

Mainstem lower Columbia winter/spring gill net seasons have had 8 inch minimum mesh size for decades.
Posted by: Larry B

Re: A Different Twist in the SRKW/Chinook Saga - 12/17/19 11:55 PM

Originally Posted By: cohoangler
A couple responses:

Larry B - I understand your point. However, Todd’s response is exactly correct. If we harvest 99 fish out of 100, and marine mammals take the last one, we blame the marine mammals for the resulting extinction. That is what is happening here. I don’t doubt that NRKW are taking more Chinook than we’d like them to, but if there were more large Chinook, there would be more for the SRKW’s.




While the NRKW population is growing and inarguably consuming more fish to include Chinook let's not forget the Chasko report which estimated that harbor seals take over 20% of Puget Sound Chinook - adjusted to adult equivalents. Their conclusions included that those harbor seals take twice what SRKW eat and 5 times what all human fishers harvest.

Bottom line, while I understand that your 99/1 is to make a point I don't believe it is factually accurate when looking at who/what is truly impacting Chinook returns.
Posted by: Carcassman

Re: A Different Twist in the SRKW/Chinook Saga - 12/18/19 07:24 AM

Larry, that may be what is affecting what's left but those seals are gonna have to go a long ways and eat a lot of fish before they even get close to the damage humans do and have done. They may eat fish, but they don't destroy and pave over and cut down and and and their freshwater habitat.

In the calculus of impacts, seals are bit players.
Posted by: Larry B

Re: A Different Twist in the SRKW/Chinook Saga - 12/18/19 10:30 AM

Originally Posted By: Carcassman
Larry, that may be what is affecting what's left but those seals are gonna have to go a long ways and eat a lot of fish before they even get close to the damage humans do and have done. They may eat fish, but they don't destroy and pave over and cut down and and and their freshwater habitat.

In the calculus of impacts, seals are bit players.


In the big scheme of things you are correct but given where we are and where we are headed in terms of human growth and development (AKA habitat degradation) uncontrolled predation to include seals is more than bit players. Guess we will have to agree to disagree on that.
Posted by: Carcassman

Re: A Different Twist in the SRKW/Chinook Saga - 12/18/19 11:24 AM

O, I agree about predation. The problem there is that we refuse to have a holistic discussion about the whole damn food chain.

One aspect that keeps being forgotten is that pinnipeds, whales, terns, cormorants an such can't simple switch to other foods; they eat what they have evolved to eat.

We need a broader view of all the resources, and I don't see the managers going there ever.
Posted by: Larry B

Re: A Different Twist in the SRKW/Chinook Saga - 12/18/19 12:00 PM

Originally Posted By: Carcassman
O, I agree about predation. The problem there is that we refuse to have a holistic discussion about the whole damn food chain.

One aspect that keeps being forgotten is that pinnipeds, whales, terns, cormorants an such can't simple switch to other foods; they eat what they have evolved to eat.

We need a broader view of all the resources, and I don't see the managers going there ever.


Unfortunately, Congress has passed legislation which handcuffs managers making it virtually impossible to take many appropriate actions in a timely manner (remembering Herschel and buddies - a lesson ignored). And then there is the "save everything" social mentality.
Posted by: Carcassman

Re: A Different Twist in the SRKW/Chinook Saga - 12/18/19 12:46 PM

But is seems we never will actually discuss the costs. We, at least the thinking folks, know that in the short term the only thing that will save SRKWs is the total closure of marine mixed stock fisheries that take Chinook destined for whale bellies. Put that out to the whale folks.

It will cost $X in lost economic business in AK, BC, and WA to get those fish to the whales tomorrow, next week, and next year. Are the whales worth it? If so, are you willing to subsidize the businesses that will be shuttered? Not only the fishermen but the hotels/lodges/restaurants/rental car/airlines and so on that will lose their source of income?

It seems to me that we don't discuss these costs because we really don't wish to save (whales, salmon, ourselves) but believe that there will be a miracle that will fix it all.
Posted by: Todd

Re: A Different Twist in the SRKW/Chinook Saga - 12/18/19 12:49 PM

As with steelhead, we'll ignore the fact that the ship is sinking, and rearrange the deck chairs and see if that helps.

If it doesn't...we'll rearrange them again. And again. And again.

Until the ship is gone.

Fish on...

Todd
Posted by: Larry B

Re: A Different Twist in the SRKW/Chinook Saga - 12/18/19 01:22 PM

Originally Posted By: Carcassman
But is seems we never will actually discuss the costs. We, at least the thinking folks, know that in the short term the only thing that will save SRKWs is the total closure of marine mixed stock fisheries that take Chinook destined for whale bellies. Put that out to the whale folks.

It will cost $X in lost economic business in AK, BC, and WA to get those fish to the whales tomorrow, next week, and next year. Are the whales worth it? If so, are you willing to subsidize the businesses that will be shuttered? Not only the fishermen but the hotels/lodges/restaurants/rental car/airlines and so on that will lose their source of income?

It seems to me that we don't discuss these costs because we really don't wish to save (whales, salmon, ourselves) but believe that there will be a miracle that will fix it all.


Yes, and those costs go way beyond the ones you identified. That said, reducing predation and particularly predation on existing outbound smolt has the potential of providing a big increase in Orca food (all other factors remaining the same). It would also make any increase in Chinook production more beneficial in terms of rate of return assuming the ocean can support them.

As for Orca food it seems the general public doesn't understand the basics to include the criticality of hatchery production.
Posted by: Carcassman

Re: A Different Twist in the SRKW/Chinook Saga - 12/18/19 05:07 PM

The Orcas eat adult salmon. I doubt that the harvesters are willing to cut back to let the potentially added smolts become adults. And, even if they did, it is 3 years until those adults come back. 3 more years of starvation.