Reds on the Redd - Fall Spawning Colours, and the Texture of the Great Bear Rainforest
Dec 05, 2016
By Will Atlas
Walking down the trail to the lake we can hear the distant roar of overflowing gulches, creeks and rivers, barreling down the surrounding hillsides and valleys. With each step our boots sink into the mud and sphagnum. Along the trail the water-soaked limbs of the cedars and salal bow to the weight of the accumulated water and the inevitability of fall becoming winter during the darkness of the coming months. The rain came suddenly overnight, playing on the tin roof like a million tiny tap dancers, until the ground was saturated. By morning more than an inch of rain had fallen, before fading to the light and persistent drizzle.
Just the day before the water was low. In the shallow riffles and glides of the stream we’d counted more than 3,000 sockeye, ornately colored salmon in their spawning garb, carrying out the final act of breeding for the semelparous fish. The fish battled for mates and breeding sites, and a few of the early spawning females guarded their redds – nests of eggs already deposited in the gravel. Preoccupied with reproduction, the salmon make an easy target for predatory bears and eagles, who litter the gravel bars and nearby stream banks with partially eaten carcasses.
The night of rain brought dramatic change to the stream. The river has risen more than a foot overnight, lapping against the bottoms of the overhanging salmonberry and alder bushes. In the tannic brown torrent, a few sockeye are visible briefly as they mill in a placid backwater before disappearing into the gloom of the rushing water and foam. The forecast looms over our field-work plans like a 1000 pound grizzly, with another 100 millimeters of rain predicted to arrive in the next 5 days. I guess we are done counting for the year.
Like the rain that soaks into the forest floor, these places sink deeply into the soul, filling the mind and the imagination to flood stage. This fall was the fifth year of our sockeye monitoring program on BC’s Central Coast, where we work collaboratively with the Heiltsuk First Nation, QQs Projects Society and the Hakai Institute to provide information on the populations of salmon that support Food, Social and Ceremonial fisheries in the region.
Since 2013 we have built a fish weir each summer in the Koeye River. A weir is a fence-like structure traditionally used for selective harvest of salmon – we use it to tag sockeye for a mark-recapture estimate of abundance. Starting this year, we’ve also been implanting sockeye with PIT tags which are detected by antennas at a series of upstream sites, allowing us to track the survival of sockeye during their often stressfully hot summer migrations. We’re also tagging sockeye smolts during their outmigration, and beginning next year these fish will begin to return, bringing with them information on their rate of survival at sea. Together this information will shed powerful light on the effects of climate variability and change across the life cycle of sockeye and other salmon, supporting informed adaptive management and allowing us to draw conclusions that may help mitigate the impacts of climate change on wild salmon throughout the Pacific Northwest.
Sockeye salmon. Photo by Will Atlas
Spawning grounds at low flow. Photo by Will Atlas