Readers may recall it was barely two months ago when I was bemoaning the lack of rain for coastal streams and the fish that live in them – my oh my, how things have changed! After possibly the wettest October in years a succession of heavy precipitation events at months end and into November have rivers large and small up in the trees in many cases and now it’s a case of too much rain, a sign of a climate environment badly out of balance.
And the timing couldn’t be worse for area salmon stocks, with fish either at peak spawning activity (chinook and chums) or with un-eyed eggs already in the gravel (pinks). Until salmon and trout eggs reach the eyed stage they are particularly vulnerable to shock from movement and given the water roaring down most river systems I have to think there’s been some shock-induced egg loss, to say nothing of gravel being shifted with the complete loss of any eggs within. Perhaps only coho are somewhat buffered against present circumstances, both because of their usually later spawning time and the fact that in many instances they like to move right up into the headwater creeks where the flows are much smaller.
One river in particular that has been hit hard by extreme flows is the Campbell River which, because of the chain of impounded lakes above the river itself to allow for hydroelectric power generation, is usually protected from the wild swings of river flow. But not this time. With torrential rain on the high ground developing in-flows to the lake system that at times in recent days have exceeded 1,000 cubic meters per second (m3/s) BC Hydro has had no option but to discharge water down the old water course below John Hart dam and over Elk Falls, which flows through the canyon and into the main Campbell River. To give some sense to these volumes one cubic meter contains 1,000 liters or 222 imperial/263 US gallons of water – you can do the rest of the math and imagine it all.
The spill, as these events are termed, initially increased to 120 m3/s but was quickly further increased to 330 m3/s, about three times the river flow itself. Once almost an afterthought as a place for salmon to spawn and rear as juveniles, over the past decade considerable work has gone into understanding and then enhancing the stream habitat of the canyon below Elk Falls, most particularly by adding gravel. The gravel beds and the eggs within are thought to be stable with flows up to 45 m3/s but with water now being discharged at 7 times that volume through the canyon it’s hard to be optimistic about the consequences.
This turn of events is particularly troubling because there’s every indication that the Campbell and Quinsam watershed has had the largest return of both chinook and chum salmon in some years. This river system is a chinook indicator stream in the management regime overseen by the Pacific Salmon Commission (Canada/US treaty) and as such considerable effort is made to enumerate all the chinook salmon spawning in it. The assessment has been already complicated by the persistent high flows which have caused the main counting fence panels at the Quinsam hatchery to be lifted, meaning that an untold number of salmon of all species were free to migrate upstream uncounted, adding a large area to the territory the deadpitch crews must now try and cover.
Despite the uncertainty there’s been a building sense by hatchery staff that the Campbell/Quinsam chinook return is a good news story, the only – big – unknown is to what degree. Even though the usual chinook broodstock capture program was unable to operate because the seining site was underwater the hatchery easily achieved the 4.25 million egg-take target from swim-in fish and has now been sending chinook, 400 females and four or more times as many males, upstream. These fish get double hole-punched in the right gill plate to indicate that they have already been accounted for. The deadpitch crews, the 2 and 3 person teams that hike the rivers each day in a predetermined sequence, were reporting lots of chinook in the Quinsam river downstream of the hatchery and a good showing in the Campbell itself, at least before the current extreme high water flow.
The high flows will flush salmon carcasses out of the system before they can be counted; in addition the deadpitch crews are reporting considerable bear activity, with numerous partially eaten carcasses being discovered some distance back in the trees. All these factors will make determining a final chinook count a considerable challenge, with completed assessment several months away.
And chums – what a fall for these salmon around the inner south coast, with large to very large returns being reported from most river systems. The five weeks of commercial fishing in Johnstone Strait by the seine, gillnet and troll sectors resulted in a combined harvest of 1.34 million fish, almost certainly a record. Weather permitting commercial fisheries are now underway in various terminal areas along the east coast of Vancouver Island as all the principle chum-producing river systems have exceeded their escapement targets, in some cases by a considerable margin.
In the Fraser River the chum return has been assessed at 2 million fish or better but commercial opportunities for harvest there have been constrained once again by the need to minimize impact on co-migrating coho and steelhead, with the Area E gillnet boats having only two 10 hour long openings in the lower river. For interior Fraser steelhead the assessed return this year has been very poor, comparable to the sockeye return. Why chums as fellow open ocean migrants have done so well while other salmon species with roughly the same marine distribution have fared so badly will be a challenge to researchers in coming up with a probable explanation.
And for those of you who celebrate the grisly execution of an early 17th century religious terrorist in England, happy Guy Fawkes Day!