Amazing Pink Salmon Returns and Salmon Farm Closures

This year saw phenomenal returns of wild pink salmon to the Fraser River, together with stronger-than-expected sockeye returns.  This has Living Oceans’ staff cautiously optimistic that removing salmon farms works to improve early marine survival and thus, adult returns of fish.  Is it proof? No, all the scientists say they’d need to see a sustained trend in favour of increased returns and rule out other factors.  But it is evidence that tends to support the proposition that young wild salmon were dying from exposure to salmon farm lice and pathogens. When this year’s adult pink salmon went to sea as smolts, the Discovery Islands and the Broughton salmon farms were almost all closed. 

This year’s evidence doesn’t stand alone. We have three examples of situations where increased returns of spawning salmon followed the removal or fallowing of farms during the outmigration:  

• In 2003, farms in the Broughton area were free of adult salmon during the outmigration period under the terms of the Broughton Archipelago Action Plan.  In 2004, returns to the Wakeman River, Kingcome River, Ahta River, Kakweiken River, Ahnuhati River and Glendale Creek showed dramatic increases. A subsequent paper authored by, inter alia, Richard Beamish and Simon Jones, confirmed that early marine survival of pink salmon had increased from 1-2% to 34% and attributed the increase to a combination of reduced lice pressure and increased nutrients, saying, “The processes responsible for the high marine survival cannot be identified with certainty, but they could include increased freshwater discharge in 2003, which may have resulted in lower salinity less favourable to sea louse production, increased inflow of nutrient-rich water to the study area, and the introduction of a Provincial Action Plan that required mandatory louse monitoring and established a fallowed migration corridor for pink salmon.”1 

• In 2022, following the closure of farms identified as being on the migration route of the Ahta River pink salmon pursuant to the terms of the Broughton Agreement, returns to the Ahta River increased by a factor of 10. 

• In 2023, Fraser River salmon are returning in higher numbers than the most generous pre-season estimates following the closure of Discovery Islands salmon farms and most of those in the Broughton.  The pink salmon run size was upgraded from a pre-season estimate of 6 million fish to 15 million.  Pink salmon abundance appears to be higher than usual globally this year; however, it remains to be seen whether such abundance occurs in areas with active salmon farms such as Klemtu and the West Coast of Vancouver Island. 

In addition to the evidence of increased returns following reduced exposure to active salmon farms, there is evidence of improved outcomes for juvenile salmon following farm removal. In a paper in press (Routledge and Morton, 2023), authors report a 96% decline in average sea lice per juvenile wild pink and chum salmon sampled in the Discovery Islands over the period 2020 to 2022. The decline in lice infestation could not be explained by variations in temperature or salinity and was co-incident with the closure of salmon farms in the Discovery Islands. 

Industry has been quick to jump on these findings to discredit them, saying that their ‘independent’ biologist (the one who does all the sampling for all the farms every year) didn’t find any difference in lice levels after farm closure. Could be because he invented the concept and location of some “pre-exposure” sampling sites, with no scientific merit; and is comparing lice levels on smolts exposed to salmon farm effluent with lice levels on smolts exposed to salmon farm effluent. Little wonder he found no difference!