Hells Gate (British Columbia)
In 1914 a large rockslide triggered by CNoR construction fell into the river at Hells Gate, obstructing the passage of Pacific salmon needing to swim upstream to spawn.
Salmon had difficulty passing through the now swifter water, and were appearing in increased numbers downstream below the Hells Gate passage and in tributary rivers and streams that they had not inhabited before.
Not only did the debris clearing operation impede their access to the river, but the government imposed new fishing restrictions, such as a four-day-per-week limit, in an attempt to preserve the salmon population.
The IPSFC carried out extensive research, and as based on their findings they recommended that fishways be constructed to help migrating salmon pass through Hells Gate.
"[1] Long before the arrival of Simon Fraser, and as early as the end of the last ice age, Hells Gate was a First Nations congregation ground for settlement and salmon fishing.
[3] During the last deglaciation 4000–6000 years ago, long tongues of ice formed wedges and dams in the river's basin above the canyon, resulting in the formation of large reservoirs and new lakes—creating optimal spawning grounds for salmon.
[4] During this inter-glacial period, salmon began to populate the Fraser River and used Hells Gate passage as their route to upstream spawning grounds.
[3] Constricted by two steep subvertical granodiorite walls, the incredibly narrow passage and high water velocity made this part of the upstream journey extraordinarily difficult for salmon, and they would hover along the shores of the river or rest in its back-eddies.
As a result, Hells Gate’s geology provided the Indigenous fishers with superb opportunities to readily catch salmon congregated at the river’s edge attempting to elude the strong currents and rough waters.
Standing on adjacent rocks or on specially constructed wooden platforms extending from surrounding cliffs, fishermen would use long dip nets to snatch the salmon.
"[3] After Simon Fraser charted the river in the early nineteenth century, it became (and Hells Gate with it) an established corridor between the Pacific Ocean and the interior of what was to become British Columbia.
[5] This nation-building project saw new railroad tracks constructed on the west riverbank at Hells Gate, connecting the British Columbia coast to the Interior (and the rest of Canada) through the Fraser Canyon.
While carving into canyon walls to create new rail-bed, rock and debris were again dumped into the river in significant volumes at various locations, including Hells Gate.
[6] In an initial attempt to redress the ecological and physical changes at Hells Gate that impeded migrating salmon, tons of rocks and debris were removed from the river during the winter of 1914-1915.
[9] The slide altered the environment of the river by increasing turbulence and density,[10] and salmon's ability to swim upstream was seriously disrupted as many fish, exhausted by the journey through Hells Gate, were carried back downstream.
[12] Unable to swim upriver, salmon relocated into rivers and tributary streams that were not previously used by them,[2] and increased fish concentration spanned up to several kilometers below the Hells Gate passage.
[22] Ultimately salmon "homing tendency is remarkably strong," therefore many sockeye easily fall victim to human triggered changes of the environment.
[23] The altered river environment threatened the salmon population, which in turn created tension between the Canadian government and the aboriginal peoples of the region.
[28] Through regulation and decreased runs, the aboriginal population experienced local famines whilst the commercial fisheries continued to operate downstream.
One of these sites was at Hells Gate, where scientists captured salmon along the banks with fill nets, tagged them, removed some of their scales for racial analysis, and then released them back into the river.
[10] Canadian zoologist William Ricker, who was one of the scientists originally employed by the IPFSC,[37] became an outspoken critic of the decision to build fishways and of Thompson’s research.
[40] Ricker stated that Thompson did not properly address these issues, and that therefore "they may be sufficient to completely invalidate the conclusion that" Hells Gate is a serious obstacle for salmon migration.
[41] Ricker also challenged other aspects of Thompson’s research, including his assumptions about the causal relationship between water levels and successful passage through Hells Gate.
[42] He further argued that there appears to be evidence (based on sex ratios above and below Hells Gate) to suggest that no significant obstruction existed after the initial clean up.
He believed he therefore had a duty to expose these intentions for what they were, so his response shifted the debate away from Hells Gate to the merits of Ricker and his fellow Canadian fisheries researchers.
[46] Thompson argued that the Fisheries Research Board of Canada had intentionally or unintentionally overlooked the fact that something was amiss at Hells Gate after the initial cleanup.
Ricker believed that over-fishing was the primary threat to the Fraser salmon run, and that it would be a "gamble" to rely solely on the fishways as a means of conservation.
[48] After receiving an official proposal from the IPSFC that included both biological and engineering data, both the Canadian and US governments approved a plan to construct a set of fishways at Hells Gate in 1944.
[58] The tourist site now boasts food outlets, observation decks and an educational fisheries exhibit that displays different short films regarding the area’s history as well an ecological documentary on the salmon run.
Hells Gate Airtram starts at the parking lot of the Trans-Canada Highway and descends to its lower terminal on the opposite side of Fraser River next to the pedestrian suspension bridge, where there is an observation deck, a restaurant, a gift shop and other tourist attractions.
