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Salmonidsof the Cariboo-Chilcotin |
About Us
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From the land-locked Kokanee and trout (including Whitefish, Rainbow Trout and blue listed Bull trout) to the anadromous (those that hatch in freshwater, migrate to the sea and when mature return to freshwater to lay their eggs) salmonids they are an important food source for wildlife and humans alike, also distributing valuable nutrients from the ocean to our region. One feature that distinguishes salmonids from other fish is the presence of an adipose fin (located along their back between their dorsal and caudal or tail fin). Their strong caudal fin propels the salmon forward through rough water, strong currents and waterfalls, in order to travel from the ocean to their hatching grounds where they release eggs and sperm. Female salmonids use their tails to dig the redd (hollow) where they lay their eggs. She may build several redds and once her eggs are fertilized, she covers the nest with gravel. Shortly after spawning the adult salmon will die and fill the water with nutrients used by other fish, birds, and numerous other wildlife species. Over the winter the young salmon begin to grow inside the eggs in their den of gravel. Only one in ten will survive. If the water gets too hot or cold, stops running (providing the egg with air absorbed through the egg wall) or dirt smothers the egg, it dies. In spring the fry (young fish) emerge, feed and grow in the stream, river or lake of their birth for up to two years. They are preyed on by ducks, herons and other fish predators. Those that survive will find their way back to the ocean where they will feed on abundant plankton, shrimp, crab, and small fish. Depending on their species, the salmonids spend from one to seven years at sea, feeding and growing. Once they return to freshwater, journeying back to their native spawning grounds, they do not eat. Living off stored body fat, these salmon battle their way home, arriving torn and scarred, most of their energy spent.
Pink salmon, the smallest of the salmon species ranging in size from 1.5-3 kg, have a short, two-year life span. Soon after they emerge from the gravel spawning beds, the young pinks migrate to the sea. Some 18 months later, they return to spawn and die. Due to this short life cycle, there is no overlap between pink "stocks" from one year to the next. Two very unique stocks of pink salmon may use the same stream for breeding. Spawning habitat ranges from small tributaries of the Fraser Mainstem, such as Churn and Williams Lake Creeks, to larger rivers such as the Quesnel and Chilcotin and the mainstem Fraser. In the Fraser River, there is a predominately larger run of pinks in odd-years. The mature males are known as "humpies" due to the large hump they develop on their backs during spawning.
Telemetry studies, radio transmitters attached to the fish, have allowed the movement of summer run sockeye to be tracked along the migratory route from the lower Fraser River to their spawning grounds in the Chilcotin and Quesnel systems. The information gathered from these studies provides invaluable insight into migratory behaviour of salmon. Persons finding a spawned salmon with one of these transmitters attached is asked to return it to the nearest DFO office.
To further improve our knowledge on the various biological and stock assessment issues, a small, portable sonar system that produces video-like images using sound has recently been used by DFO. The Dual Frequency Identification Sonar (DIDSON) has the ability to confirm deep water lake spawning areas and observe associated habitat requirements and spawning distribution and densities. Steelhead trout are the anadromous form of rainbow trout. They are born in freshwater streams where they spend their first 1 - 3 years of life, then migrate to the ocean where most of their growth occurs. After spending 1 - 4 growing years in the ocean, steelhead return to their native fresh water stream to spawn. Unlike Pacific salmon, steelhead do not necessarily die after spawning and are able to spawn more than once. Most steelhead spawn from December through April in small streams and tributaries where cool, well oxygenated water is available year round. Anadromous steelhead and resident rainbow trout did not arrive from two distinct evolutionary lines. Anadromous forms of trout can convert to resident populations when drought events or damming of rivers blocks their access to the ocean. Conversely, resident trout populations can become anadromous if ocean access becomes available. It is typical to have both life history patterns occurring in the same stream. In fact, resident and anadromous parents can produce offspring of both varieties. It has been speculated that there is a food availability trigger which determines whether a particular fish emigrates to the ocean or remains in the stream. It may be that if there is abundant food in the stream and a fish is growing at a rapid rate, it will remain in the stream. If food is limited and growth is slow, the fish will have a tendency to emigrate. Steelhead habitat requirements change as they go through different life phases. Adult steelhead need to have access to their natal stream. This means that streams must be free of barriers to migration, as the majority of spawning occurs in the upper reaches of tributaries. Adults also need access to spawning gravel in areas free of heavy sedimentation with adequate flow of cool, clear water. Escape cover such as logs, undercut banks and deep pools for spawning adults is also important. For steelhead eggs and pre-emergent fry the most important consideration in terms of habitat is cool water with adequate dissolved oxygen. Fine sediment will smother developing eggs, so the area must not have excessive fine silt or mud. Elevated water temperatures >18°C. can greatly impair growth rates of juvenile steelhead. Warmer water also holds less dissolved oxygen and increases a fish's susceptibility to disease. The rainbow trout, most widely distributed member of the trout family, is one of the top five sport fishes in North America. The rainbow has an elongated body, with an iridescent reddish band running along each side from head to tail. In the sea-run type, the back is dark blue, with sides and under parts silvery. In the non-migratory type, the back is bluish to olive green shading to silvery green on the sides and white over the belly.
"Kokanee" is a native word meaning "red fish". Kokanee are the land-locked form of sockeye salmon. Because they never migrate out to the ocean to feed, Kokanee are much smaller than sockeye, but other than their size have very similar identifying characteristics as sockeye. Most Kokanee live in a lake for most of their lives and can usually be seen spawning near the edge of a lake or in a small tributary that feeds into the lake. Spawning time is generally during the month of September in the Cariboo-Chilcotin region. Average length for a Kokanee is 10-18 inches. Kokanee are food for numerous fish and waterfowl species such as rainbow trout, lake trout, burbot, mergansers, and common loon. The blue-listed Bull trout is a predator, and as an adult eats almost exclusively other fish. Threats to the bull trout include loss of habitat and habitat damage, competition with introduced species and illegal poaching either intentionally or unintentionally through misidentification. A late-maturing species, the bull trout doesn't spawn until after it's sixth year. Bull trout require clean stream gravel and cold water temperature to survive. They are like "canaries in a coal mine", serving as an early warning system for habitat changes such as stream siltation. Studies have shown that when the amount of fine sediment (particles less than a quarter of an inch) amount to more than 40% of the stream bottom, less than ¼ of the bull trout eggs will hatch and survive to viable fry. Many anglers have a difficult time distinguishing bull trout from other species - particularly the lake trout. Both the bull trout and lake trout are chars: members of the trout family which generally have light spots on a dark background. The most reliable way of telling a lake trout from a bull trout is the tail. The lake's tail is deeply forked; the bull trout's tail fin is only slightly forked. The bull trout has a body that is snake-like and the head does not dominate the body. The names, bull trout and dolly varden, were used interchangeably until 1980 when the bull trout was genetically proved to be a separate species. There is no definitive way to identify bull trout from dolly varden in the field. Whether you are watching grizzly, bald eagles, or black bear fishing spawning salmonids along the Atnarko River (Tweedsmuir Provincial Park), Quesnel Lake (Cariboo Mountains Provincial Park), the Bowron chain (Bowron Lake Provincial Park), or Horsefly River or Lake (Horsefly Provincial Park), the enjoyment of seeing the life cycle of a salmonid in completion cannot help but bring awe.
Original material in this website may be reproduced in any form without permission on condition that it is accredited to the Cariboo Chilcotin Conservation Society, with a link back to this site or, in the case of printed material, a clear indication of the site URL. We would appreciate being notified of such use. Although care has been taken in preparing the information contained in this web site, the CCCS does not and cannot guarantee the accuracy thereof. Anyone using the information does so at their own risk and shall be deemed to indemnify CCCS from any and all injury or damage arising from such use.
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