The earliest record of salmon in North America is of the ‘Saber-Tooth Salmon’ in fossils dating up to 7 million years ago … at up to three meters long these weren’t your typical ‘salmon’!
There are seven species of Pacific salmon. Five of them occur in North American waters: Chinook, coho, chum, sockeye, and pink. Masu and amago salmon occur only in Asia. Note: Steelhead trout are often listed as an eighth Pacific salmon, but unlike other Pacific salmon, they are capable of repeat spawning and do not die after spawning.
Pacific salmon are named Oncorhynchus. The name is derived from the Greek onkos (“hook”) and rynchos (“nose”), in reference to the “kype” – the hooked jaw that forms in males during competition for females during mating season.
There are more than 9,000 salmon populations (species and stream combinations) in B.C., organized into about 450 conservation units applied in resource management.
Pacific salmon are distantly related to Atlantic salmon but they can not inter-breed as these species have different numbers of chromosomes.
Pink salmon are the smallest and most abundant species and Chinook salmon are the largest (exceeding 50 kilos) but least abundant species. Interestingly, they have exactly the same number of scales.
Pacific salmon undertake anadromous migrations meaning they reproduce in clean, cool, freshwater streams, but rear for a portion of their life in oceans, where they accumulate more than 99 per cent of their adult weight.
Pacific salmon are also semelparous, meaning that the most adults die after reproduction and become nutrients and food in the freshwater systems. They are the nutrient backbone to B.C.’s coastal ecosystems.
Pacific salmon return ‘home’ to their natal streams to reproduce! Adults return to the same streams that their parents used. This behaviour has allowed the development of extensive genetic diversity within each species, allowing salmon to be highly adaptable.
Scientists believe that homing is accomplished by tracing ‘pheromones’ or chemical signatures of the home stream! Salmon have an extremely keen sense of smell – they can smell chemicals down to one part per million.
Once adult salmon return to freshwater, they do not eat. This means that adults can go six months without food while transferring body fats into their gametes for reproduction.
Salmon hear using low frequency sound waves which vibrate through the water to a row of sensory pores called lateral lines on the sides of the salmon.
Salmon in their saltwater phase travel an estimated 18 miles a day, but they are capable of maintaining an average of 34 miles per day over long distances.
Salmon can migrate more than 3,000 kilometres upstream through freshwater to spawn (Yukon River). That is comparable to driving halfway across Canada.
Salmon often travel 50 kilometres per day on their spawning journeys. This is equivalent to running more than a marathon every day!
Salmon can jump up to two metres to cross obstacles in rivers – the same height some Olympic athlete can jump.
A typical orca eats 25 kilograms of salmon a day. For the 300 resident orcas in B.C., that translates to an approximate net consumption of 1,000 tonnes of salmon per year, which is the same weight of 100 large trucks.
The city of Vancouver has lost most of its salmon streams due to urban sprawl. Out of about 50 streams, only two remain.
Females lay thousands of eggs (usually between 2,000 and 10,000), unfortunately, at present less than one percent of these eggs survive to the next generation.
Approximately 80 per cent of ‘farmed’ salmon in B.C. are Atlantic salmon, not the local Pacific salmon variety. Salmon farming usually refers to the rearing of salmon in net-pens in coastal waters until they are harvested for market. But 2014 saw the first land-based commercial Atlantic farmed salmon brought to market by Kuterra Farms, owned by the Namgis First Nations. The Foundation was proud to partner as an independent biological monitor for the project.