Image from: http://www.fish.state.pa.us/pafish/fishhtms/chap15trout.htm
Species: Chinook, Chum, Coho, Pink and Sockeye
Scientific names: Oncorhynchus tshawytscha (Chinook), Oncorhynchus keta (Chum), Oncorhynchus kisutch (Coho), Oncorhynchus gorbuscha (Pink), Oncorhynchus nerka (Sockeye)
Statuses: Mostly: Endangered, Threatened or Special Concern; Some: Not at Risk
The grizzly pounces on the salmon, splashing foam in the water as it does so. It’s a feast for the bear, well caught and well done, but there is something missing. The grizzly casts its mournful gaze at the roaring river, where once, there were thousands, no millions, of sleek bodies swam upriver, jostling each other in their haste. The catches of spring were plentiful and delicious, and the salmon murmured in the flow of the water. Now there is only silence.
Imagine you are that grizzly. Once, long ago, salmon swam abundant in the river, but now there are barely any. You know there is a disturbance in nature. Someone, or maybe many people, has been eating your fish. A pinch of their former number appears, and less return each year. You know that if you also keep eating them, they’ll eventually disappear. But you have cubs to feed, and salmon are easy prey. Why is this happening? What will you do?
What will we do? Salmon, one of Canada’s most prized fish, is dying out. Not just any salmon, either: Pacific Salmon, which includes five well-known species: Chinook, Chum, Coho, Pink and Sockeye. We need these precious fish too, because they are part of our environment, part of our world, and part of our life.
Appearance
CHINOOK: Chinook have blue-green backs and tops lightly speckled with spots and silvery sides. They are spotted from the bellies up to their sides with black dots. They soon become gold in appearance when it is time to spawn.
CHUM: Chum salmon and sockeye salmon are very similar in appearance: both have silvery sides, though they have black specks on their sides, whereas sockeye do not. However, they can be easily distinguished when spawning season arrives; chum salmon turn dark gray while sockeye turn red.
COHO: Coho salmon have bright, shiny silver scales in their saltwater stage. However, when males evolve into their freshwater stage, their mouths become hooked and their bodies flush red and orange.
PINK: Pink salmon are not as “pink” as you think they would be! In fact, they are metallic blue to bluish-green in colour, and have a small hump before their dorsal fins. Their body is also covered with light specks, and during mating season, they turn dark with pink tints, and have green blotches on their sides.
SOCKEYE: Sockeye salmon are bluish silver and are closely alike to chum salmon. During mating season, they undergo a wondrous transformation and become stark red with olive-coloured mouths.
Habitat
Pacific Salmon don’t only live in the Pacific Ocean, as their name suggests! They, like all other species of salmon, are born in rivers and begin their lives there. When they are juvenile fish, they swim out to the ocean – nobody knows why. Mainly, salmon live off the coasts of western Canada, such as Alaska. From there, they fan out over and around the Pacific Ocean; some salmon even swim to the Atlantic Ocean.
Diet
What salmon eat depends on what stage it is in life. For example, alevin and juvenile salmon eat small, microscopic plankton called zooplankton, as well as larval and large invertebrates. Salmon in the ocean eat oceanic animals, such as krill, smaller fish and pelagic amphipods.
Families
Once every year, a spectacular journey takes place in the Pacific Ocean and through the rivers of the Pacific Coast: the Pacific Salmon migration. After several years of living in the ocean, Pacific Salmon enter streams and rivers, instinctively returning to their birth rivers. They come from the Pacific Ocean all along the North American coast, from northern California all the way around the arc of the Gulf of Alaska and into the Bering Sea, just to return to the home to spawn. Nobody knows how they find their way back into their original waters, but somehow, year after year, they have been able to.
The journey is harsh and long. Salmon will travel for miles and miles upstream, around rocks, jumping up falls and swimming, swimming, swimming nonstop. Only when they reach their home streams do they rest. As more and more salmon pour into streams and rivers, the salmon begin to mate and lay eggs in small, cleared nests of rocks called redds. The males incubate the eggs after they are laid, and all salmon, both male and female, die. Their bodies are eaten by bacteria and decompose in the water, to become nutrients for the baby salmon yet to hatch.
Threats
Over-fishing, pollution, climate change… these three threats are a mere few of a ton of threats that Pacific Salmon face – and the more obvious ones. Like many other species, Pacific Salmon suffer from less obvious but far more harmful threats – take salmon farming, for example. More salmon released from salmon farms seems all very well and more environmentally sustainable, doesn’t it? Or does it? In truth, young captive salmon have less immunity to natural diseases and attract parasites before they are released into the wild. When they are let into streams and rivers, the parasites infect wild salmon and eventually kill them. Another threat that kills salmon is habitat change caused by deforestation, mining and dams. The loss of trees in one area causes serious erosion that falls into rivers and ponds, contaminating the fresh water.
In 2009, the Fraser River sockeye salmon population fell 90% below expected numbers – just 1% of what it was one hundred years ago! Only one million of the recent one hundred million survived to return to spawn. However, that one million isn’t even close to enough to supply food for both animals and people. This is where salmon farming comes in. Though salmon farming is producing more salmon in general, their parasites are killing wild salmon. The fight to save salmon is a fight of the lesser evils.
Fun Facts
1. Dams kill over 20% of adult salmon and 50% of young salmon.
2. Salmon normally have growth spurts during the summer and grow more slowly during the wintertime.
3. There are several different life stages in a salmon’s life: first the egg, then the alevin, then the fry, and lastly the spawning adult.
Information from:
http://www.nwr.noaa.gov/ESA-Salmon-Listings/
http://wdfw.wa.gov/fish/chum/chum-9.htm
http://www.goldseal.ca/wildsalmon/species.asp
http://cybersalmon.fws.gov/pink.htm
http://www.bcadventure.com/adventure/angling/game_fish/pink.phtml
http://www.vanaqua.org/education/aquafacts/salmon.html,
http://www.nationalgeographic.com/xpeditions/lessons/09/gk2/migrationsalmon.html
The Wilderness Committee Newsletter (Vol. 28, No. 1: Spring 2009)
The Wilderness Committee Newsletter (Vol. 29 No.1: Winter 2010)
