In the early 70s there was a large number of harbor seals using Gertrude Island in McNeil Island's Still Harbor. I am sure that those animals were the nucleus for rapid growth in South Sound after the MMPA came into law. Maybe not the only factor but certainly a significant one.

Problem with that idea is that the anadromous cutthroat south of the Narrows are doing fine and increasing. Maybe the seals only eat migrants...

A big mistake that people have made with hatchery programs over the years is that they just assume that they will be successful. As Carcassman pointed out, there has been, perhaps still is, a severe decline in survival of yearling releases in S. Puget Sound that started in the late 1980's. At that time, as I said, there were some programs that were releasing over 30,000 pounds of fall Chinook yearlings and only contributing 20 or so fish to catch and escapement. It made no sense to continue these programs as they were basically just flushing fish down the toilet. So I would suggest a more accurate statement would be "Hopefully someone will be able to gather return data to determine IF there is improvement in adult returns by these fish versus those released into the river."

It will be interesting to see if any try to return to the pen location, providing some good king fishing off the dock. I caught one there years ago that was fairly good sized. It was caught off the fuel docks right after dusk on a glow in the dark buzz bomb. I had to gill it and throw it up on the dock. We were having a church picnic and I was able to run back after about 10 minutes with the fish.

As Oncy says, dealings released out of Minter returned fewer fish than fingerlings released at the Muckleshoot hatchery on the White. Same stock, but one went through the Narrows. In 00s and into the teens the acoustically tagged steelhead smolts had really low survival to open ocean when the originated in the southern Sound. Further north they did better.

Again, to my knowledge, all that was done is collect that data and not look into a reason.

At one point, I understand that Squaxin (and perhaps the State) were planning on marking a group of fish, barging them past the Narrows (I can't remember the destination) and releasing them there to see if there would be any difference in survival. I have seen reference to this several times, but don't know if it actually happened and what the results were.

They did it in 2016, though I never heard the results of the study.
If I recall correct, some were released at the Narrows, near Vashon and others at PNP.
SF

https://www.youtube.com/watch?v=qLxY0nONkTw

https://wdfw.wa.gov/sites/default/files/publications/01969/wdfw01969.pdf

I know there was a push to barge steelhead smolts out into the Straits but I don't think anything came of it.

I see from the one page description of the project that they might modify their release locations based on acoustic tag recoveries in 2016, but no indication of when the actual transport may have occurred. The youtube video says the spring of 2016 as a start and it shows fish being transported and released apparently at Vashon. The one pager was not "published" until 2017. The release sites evaluated were going to be Squaxin Is., Vashon, and Pt. No Pt.

Since they started this in 2016, it would have been with brood year 2014 coho that would have returned as adults in 2017, seven years ago. Some results should be available in those 7 years, but I can't find anything about this project other than the one pager whose link is above.

Way back there was an issue about the proper stock to use in the Westport pens. It was thought by the locals that the Satrap stock would put more fish in the sport fishery than the Hump stock. So, the locals paid for CWTs. When it became time to look for returnees WDFW didn't have the money to go looking; so they didn't.

Just possible that there were no funds to monitor for the returning fish. At least a cynic would think that.

What years? I might be able say that on the Satsap way back , had huge returns, and great fishing.

The Westport Net Pen coho stock comparison study used CWT groups from 1988-90 broods. One Humtulips code was matched against 2 Satsap Springs CWT groups. Overall adult survival was best for the Humptulips groups but that was partly due to better escapement accounting. For 1988-89 broods, the Satsop groups contributed slightly more to "Grays Harbor Estuary" sport. For 1990 brood Humptulips had a much higher contribution. IMO there isn't a clear standout.

My recollection is that the hypothesis was that by releasing fish closer to the ocean they would improve returns. There were several release sites north of the Narrows.

The word I heard was that there were no improvements hence no efforts to move into a bigger effort. One has to wonder if the testing should have been over a longer time and/or if the sampling methodolgy and analysis was sound.

Most of the time studies seem to be short, a couple years. Long term studies are what is needed because no one year is "normal" or "average".

I read a summary of the studies that were done on a single island in the Galapagos, looking at evolution among two or three species of Darwin's Finches. Essentially, one conclusion is that of they hadn't studied the island continuously for the 20-30 years they would have come up with incorrect conclusions. It took that length of time to actually see what was going on with all of the environmental changes going on, too. It was the Grant's, a husband and wife team, that did these studies.

I would add that one of the strengths I saw in Fraser sockeye management in the 80s was that every week we not only reviewed the current data but looked at all the historic (this went back to 1890 in some cases) information to see just what the current year best looked like. So, when decisions were made, the decision makers couldn't claim ignorance or "we didn't think of that". Obviously time consuming, but the fish were doing well then.