The question is in the topic ..... thoughts?

Or trigger an earthquake out of the Seattle fault line?

I posed the question because of a report that I read a while back about Hood Canal Bridge noise possibly impacting the survival of outbound smolt (if memory serves correctly). I don't know if the viaduct noise has had a likewise negative impact, but if it has, I can only imagine what the jack hammers sound like, and whether or not the new tunnel which has more surface contact with the ground will be transmitting more noise/vibration. Any studies done concerning this type of impact? Perhaps I just need more coffee.

Lots of info on noise impact on Orcas to include ferries. Just my observation as a kid hanging out and fishing off the public access portion of the Edmonds ferry dock back in the 50s (it is now off limits; my antics then crawling around and under the pier would get a kid arrested now) was that the ferries had little impact on fish in the area.

What I have gleaned about the Hood Canal bridge is that it creates a barrier to salmonid and particularly steelhead smolt trying to out-migrate. Another barrier concentrating smolt to the benefit of predators.

So, are you worried about the fish in the Seattle Aquarium?

Those would be the closest fish to the viaduct.

Don't think the fish minded too much when they rebuilt the sea wall down on the waterfront. Can't imagine any work on the viaduct, which is several hundred feet East of the water and on dry land, would have any effect on anything, other than Seattle traffic.

PS. Even if the vidaduct was floating on top and in the middle of the Duwamish River (only river in the area where there are outgoing salmonid smolts in Elliot Bay), any and all construction noise would be a welcome treat compared to the filth and pollution those little fishies have to swim through to make it to Elliot Bay.

Not like Elliot Bay is a whole lot cleaner.

Come to think of it, I'm surprised *any* salmon makes it out of the Duwamish and Elliot Bay...let alone make it back as an adult to that sespool.

I suspect that ship noise (and pollution) was a whole lot higher in (say) the early-mid 40s and again in the early 50s with all the military coming and goings. Don't think they tried to be quiet.

And a whole lot fewer pinnipeds!!

There was that. But probably more SRKWs and more salmon and steelhead, too.