Wow Fishhunter! First thing you need to do to help this situation is to educate yourself on the facts surrounding the Fraser River sturgeon fishery, instead of making outlandish comments like you have.
As mentioned, this sturgeon could have died from a variety of scenarios. Thankfully, through scientific evidence, supported by the over 45,000 sturgeon tagged and released we know that the mortality rate of catch and release sturgeon fishing is virtually nil. Thus why we still have a fishery for them. There is so much data indicating the multiple recapture of fish over many years. These fish are strong, and very hearty, it takes ALOT to affect them in such a way to kill them.
As for the fish floating down the Harrison, most of the bright sockeye seen dead are affected by a parasite that affects their kidneys. They die prior to spawning and they generally appear in good health otherwise. This is seen on most years in the Harrison. As also said, the FN "release" the males as they are of no commercial value to them. There tends to be a high mortality rate with these "released" males.