Originally Posted By: Carcassman
The pink/freshwater rearing effect is complicated. It worked well in other PS streams, but.....

The beneficial effect (as shown in PS and BC) was in decreasing smolt age. Younger smolts are more abundant than older for a given watershed. So, while the escapement numbers went down, what was the actually return per spawner to first spawn, by brood? That is what the pinks increased. Plus, what was the composition of the run with respect to repeat spawners? If that number declined, increased nutrients benefitted the smolts.

The systems that show benefit are those systems where we have a rather complete data base. The escapement is a count, or survey of 100% of the anadromous zone. Ages are collected over the whole run timing as age changes over time; sampling only the last half, for example, significantly misses some age groups.

In AK, where they had significant and immediate response by coho to pinks the steelhead response was close to a decade later. Same in some BClake fertilization where the Gerrard rainbow responded about 5 or 6 years into the project while the kokanee response was rather immediate.

The last confounding aspect is that the super abundance of pinks in the N Pacific, and it might be more tied to the AK PNP projects than PS pinks, has shown that the adult pinks are correlated in depressing Chinook, coho, SRKWs, and Antipodean shearwaters.

Also, the increase in pink spawning in the Stilly seems to have occurred about the time Larry's Pets (the pinnipeds) really zoomed up. In this case, unless we know what happened in freshwater with regard to smolt age and number we don't know if the pinks didn't help or if the seals ate the proceeds.

We can't, and we are all guilty of this, look at one piece of the puzzle as if it were independent of all the others. Which is why, I am afraid, we are rather doomed to failure because there are so many things to fix out there.


My pets?? Ha!!

Seriously, I agree with most of what CM opines - and that many of the relationships are subtle and not clearly understood.

That said, we sport fishers have born the brunt of restrictions relative to our overall combination of adverse impacts and positive contributions. One only needs to look at the total unwillingness of the various agencies to address the impact of pinniped and avian predation on Chinook.

If just seals are taking 25% of out migrating Chinook smolt I have to wonder what the total loss is to all predators before those smolt exit Puget Sound? It may not be the only 800 pound gorilla in the room but it seems to be the one few "managers" and fewer politicians want to discuss openly.
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