Graph the increase in seal population over the decrease in success in the blackmouth fishery. It is impossible to not see the inverse relationship and also conclude there is a cause and effect relationship. One might say it was the increasing population of seals feeding year around on those juvenile Chinook which effectively killed that program.

Something that rarely discussed is the fact this seal/salmon problem is a symptom of ecosystem failure.

A recent harbor seal diet study found that during the spring (smolt migration period) only 1 to 2% of the diet were juvenile salmonids. Yes given the number of seals and the length of time the smolts are vulnerable that can add up to a lot of fish the fact remains the smolts are not necessarily the preferred food item.


The various cod (hake, Pacific, and Pollock), herring, anchovies, shiner perch, staghorn sculpins, etc. are all eaten at much higher rates than Chinook smolts. I would find it interesting to learn what is limiting the historic harbor seal forage base. Is it being limited by the seals themselves or some other factor. Are there actions that could be taken to increase that forage base?

The whole salmon and orca recovery discussions consistent lack a general holistic approach to required actions.

Curt

Smalma, when discussing the impact of pinnipeds in general and seals specifically to Chinook returns the use of the word "only" when describing a 1-2% of their entire annual diet is misleading. Being highly mobile and opportunistic predators they will go "where the livin' is easy" to quote from a song's verse. As I recall the seals' recent impact was estimated at just over 26% of outbound Chinook smolt against an estimated Chinook smolt population of over 46MM. Do the math.

However, I do agree with you that with Chinook smolt representing only 1-2% of annual diet those seal numbers are probably not being limited by Chinook smolt but, rather, by those other prey species you mentioned not the least of which is forage fish.

At the Commission meeting on Friday I sat next to a young woman who was there to testify against seal culling as she said she had proof that culling in other areas did not achieve the intended goal. I responded with the "Okay, if not predator control then what?" Among her suggestions was increasing forage fish habitat. But would that really solve the problem? Would an increase in forage fish shift seal predation away from Chinook smolt or would it result in increasing the carrying capacity within Puget Sound for all of those predators for which forage fish is the limiting factor thereby allowing an increase in the total numbers of those predators to include seals. And if the total number of seals is increased would that result in an increase in their current 26% impact on Chinook smolt?

Basic biology. If the pinnipeds are increasing, they have enough food and habitat. When the populations stabilize, they have reached capacity. Increase stuff they eat, and they'll increase.

Another little interesting tidbit from the Staff's presentation is the slide which indicates that NOAA/NMFS has not established an Optimum Sustainable Population (OSP) for harbor seals.

In an article entitled Trends and Status of Harbor Seals in Washington State: 1978-99 by Harriet Huber and Jeff Laake as published in the AFSC Quarterly (Oct-Nov-Dec 2002) there was the following:

"Status Relative to OSP
Although the evidence is not strong, the growth models of both stocks agree with the speculation that MNPL is in deed greater than 0.5 K (Table 3). The predicted population size for 1999 is very close to K for both stocks (Table 3), and none of the bootstrap replicates predicted a 1999 population size that was below MNPL. These results provide overwhelming evidence that both stocks in Washington are above MNPL and meet the guidelines for OSP. These stocks could decline or be reduced by 20% and they would still be above MNPL with a high degree of certainty (Table 3). The coastal stock recovered earlier than the inland stock as evidenced by the status of the stocks in 1990 (Table 3)."

In that article they had five geographical areas covering what the Staff presented as three inland areas - I point that out to avoid any confusion. The combined total population of harbor seals for those inland areas east of Tatoosh in the last year presented (1999) was 8,949. If you reduce that number by 20% you would arrive at 7,159 animals.

Compare that to the Staff's cited three year average (2013, 2014, 2015) total number of 19,029 for that same area and you would be able to reduce the population by 11,970 animals or 62.4%. Is there any doubt that such a reduction wouldn't have a significant positive affect on Chinook returns all other factors remaining the same?

Note: This post has not been peer reviewed and if there is an error I welcome any (polite) corrections. It is a starting point for discussion given the vacuum created by the absence of an OSP in the presentation to the Commission.

The conundrum we have is that the pinnipeds are way above a sustainable level and the SKWs and Chinook aren't. Wonder if the fact that we stopped killing the seals has any impact on their recovery.

They live in the same water, they eat many of the same foods. It's the argument I make that FW can't be all that crappy because searun cutthroat and native char (anadromous) seem to be rebounding. They use the same FW and Chinook and steelhead, they o into the same Sound. I know it's simplistic to say that the only problem;em is killing the fish, but it is the one we won't deal with. That, and killing pinnipeds.

Seems if we can't take the necessary actions to get SRKW fish now (close fisheries, kill pinnipeds) then we just aren't going to get there.

Being a similar straight line thinker the clear answer is YES. Fiddle with the numbers but there is no denying the evidence.

And I will add that when the issue of pinniped predation was raised as a factor in rockfish recovery NOAA folks opined that seal scat studies in the San Juans indicated a very small percentage with rockfish DNA and that the rockfish DNA had not been identified by species (see, speak and hear no evil). They further indicated that since those listed rockfish were generally found in deeper water than where seals forage there wasn't an issue. Then when they tried to justify MPAs they said that the MPAs needed to run to the beach to provide sanctuary for juveniles of those same listed rockfish species - and therefore be susceptible to seal predation. (Left hand meet right hand.)

And that doesn't even address the increasing population of California seal lions and Stellar sea lions which forage at much deeper depths and are known to eat rockfish.