Only 1.4 million of the highly prized salmon returned to spawn that year.
Justice Bruce Cohen, of B.C.'s Supreme Court, has held months of hearings, collected more than three million pages of documents and heard from 179 witnesses in leading the $25-million inquiry.
Observers are hoping the inquiry report can live up to the anticipation.
"We have to all hope, and we have to hope like hell that it's quite good and it will direct the Harper government to question where they're going," said Otto Langer, a former Department of Fisheries and Oceans biologist.
Langer, who was an intervener in the inquiry, told CBC News he believes Cohen didn't dig deep enough into alleged dysfunction at DFO, made worse, he said, by funding cuts and legislation that gutted habitat protection.
"If we don't make a stand in British Columbia ... 100 years from now, we might have very few salmon runs.”
Fish farm question
Cohen is also expected to weigh in on whether B.C.'s controversial fish farms have anything to do with the sockeye’s unpredictability and decline since the 1990s.
Industry spokesman Stewart Hawthorn, of the B.C. Salmon Farmers Association, thinks the report will find farming is not the issue.
"Just going back to what the evidence said, it was quite clear that wild salmon and farmed salmon can co-exist," Hawthorn said.
Wild salmon advocate Alexandra Morton, an intervener as well as an inquiry witness, said that view is "outrageous."
“The collapse of the Fraser sockeye began exactly when those farms went on their migration route,” Morton said.
Although only a fraction of the fish that were forecast showed up in 2009, the 2010 run saw 35 million sockeye, the biggest run since 1913. About 4.5 million returned in 2011 and just 2.3 million in 2012.
The offspring of those few sockeye that made it back in 2009 are now out in the ocean and are due to comprise the run for the summer of 2013.