Thanks for this littlechucky. On one of the other threads
http://www.sportfishingbc.com/forum...on-can-adapt-to-warmer-environment-study-says a few months ago - we had quite a long conversation/debate on the challenges and successes of hatcheries.
To add to that debate both from the past thread and this one: hatcheries face many challenges with success in repopulating depressed populations of fish - the least of which is that many - if not most - hatcheries do not spend enough time/effort in checking on their success and altering production protocols, as the article you posted pointed-out. The reason for this is quite simple: marking fry is a considerable time/personnel issue, and most hatcheries already suffer from underfunding and understaffing and really can't take on more work in addition to pumping-out smolts.
So there is an assumption that every fish/smolt going out the door is a success - and everyone prays and hopes and waits to see what will happen in about 4 years time.
In order to assess the ocean survival rate - hatchery fish must be marked somehow in order to differentiate them from their wild cousins. Typically, the adipose fin is removed from hatchery smolts when they are small fry - and sometimes a chip (PIT tag) is placed under their skin on the nose. It is very time consuming to do this to say 300,000 Chinook smolts. Then, enough hatchery fish have to return with the wild fish - and be found - in order to generate an estimate of ocean survival rates. That is another commitment in people/time/money - but can often be accomplished on smaller watersheds when carrying-out a broodstock take.
If the ocean survival rates mirror and nearly match that of their wild cousins (so, this process must also be accomplished on the wild stocks - a smolt fence and/or tagging) - then you are doing well. If not - you are doing something not so well. So - there should be 2+ production protocols for each hatchery - so you can fine-tune what works. The article you posted spoke about these changes in production protocol.
Most hatcheries hobble along with funding, personnel and infrastructure - and just doing it one way is all they can manage. Finding money to differentiate the water system and tanks and trying something new - is very difficult for most hatcheries.
Changing gears a little - I like what the Alaskans do wrt their hatcheries. They get around common-property issues there by having terminal fisheries pay for their hatcheries, and they use an efficient way of marking their smolts. They use thermal marking to produce a morse-code imprint on the very early growth of the otoliths of the smolts - and use that imprint to differentiate wild/hatchery stock and figure-out things like ocean survival rates.
Thermal marking is a process where (usually) fertilized and growing eggs are subjected to rapid increases and subsequent decreases in ambient water temperatures in either Heath trays or an upwelling box - which shows up later on the otoliths. You can do hundreds of thousands of eggs in one go - verses the work in manual handling of live smolts when the adipose is being clipped. Unfortunately, it is also "terminal" for the fish to dig-out the otolith - so that method has some limitations in that you can't easily ID returned hatchery fish w/o killing them.
I appreciate the article and the thread, littlechucky. Good discussion.
