Thank you. I wasn't given any terms of reference for what you wanted me to talk about, so I'll talk fairly generally about what has happened with Pacific salmon.
I've been doing research on Pacific salmon populations for over 50 years, and my research has focused in particular on trying to understand why there have been severe declines in many salmon and herring populations. The Department of Fisheries and Oceans has responded to these declines by closing various fisheries, but those closures have not reversed the declines. Many DFO scientists blame the declines on environmental factors that we can't control, such as climate change, but in recent years I've come to believe that the declines have substantially been due to massive increases in marine mammal, seal and sea lion populations and their predation impacts. The number of seals and sea lions on the Pacific coast today is probably double what it was for the last several thousand years, when first nations peoples harvested them intensively. We're in an unprecedented situation in terms of predation risk for salmon.
As an avid sport fisherman since 1969, I've been particularly dismayed over the years at the collapse of the Georgia Strait sport fishery, one of the most valuable fisheries on the Pacific coast. When I first started fishing in the Georgia Strait, there were close to a million angling days of fishing every year, with a net economic benefit from non-resident tourism of over $60 million a year for the local B.C. economy. That's more valuable than the commercial sockeye fisheries of B.C. That fishery has declined now by over 80%, mostly between 1980 and 1995, and there's been no retention of coho salmon at all for over 20 years.
When those declines first started in the 1980s, scientists like me blamed the problem on overfishing. We advised former fisheries minister John Fraser to introduce more restrictive regulations, which happened, and the commercial troll fishery closed completely. However, the stocks just kept declining. Then we started blaming hatchery production and other factors, such as warming water, but the stocks continued to decline anyway.
None of us suspected that marine mammals might be a cause of these declines until a major paper came out from DFO scientists in 2010 showing that the seal populations in the Georgia Strait had increased by about tenfold between 1972 and 2000 in a pattern that was pretty much a mirror image of the decline in the Georgia Strait sport fishery.
Today there's a big controversy. We see two major explanations for why those declines occurred and why the stocks continue to be low. One of them is climate change, and increasing water temperatures in particular. The other one is the increase in seal predation. Our data show that the amount of juvenile salmon eaten by seals each year in the Georgia Strait is enough to directly account for the decline. There are almost as many juvenile chinook and coho going into the Georgia Strait every year as juveniles as there were back in the 1970s, but they're not surviving their first year in the ocean.
We can't prove that the consumption that we calculate of those juveniles by marine mammals is what we call additive. We can't prove that if you took away the predation, the fish would survive. It could be that other mortality agents would kill just as many of them, because there's still something wrong with the ocean. It would be a large-scale management experiment to reduce seal populations through commercial first nations harvesting in order to see if we can restore at least some of the economic value of that sport fishery and perhaps benefit other really endangered stocks, such as the interior Fraser coho salmon.
More broadly, we've been doing research recently suggesting that the big increases in Steller sea lion populations in our waters outside the Georgia Strait have likely been at least partially responsible for the Fraser sockeye declines that triggered the Cohen commission and are very likely responsible for collapses of two of our major herring stocks on the west coast of Vancouver Island and in the Haida Gwaii area.
I've recently helped the Pacific Balance Pinniped Society develop proposals for commercial and first nations' harvesting of seals and sea lions, aimed at reducing these pinniped populations to about 50% of their current levels and keeping them nearer the levels we think were present when first nations people were harvesting them on a sustainable basis. Those proposals went into DFO two years ago, and the department has been sitting on them for over two years with one excuse after another for not taking any action. This is understandable, considering how controversial any proposal involving marine mammal harvesting is on the Pacific coast.