CBC News Indepth: Salmon

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FARMED SALMON

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CBC STORIES: B.C. salmon numbers cause for concern (Sept. 20, 2004) Flame retardant levels higher in farmed salmon (Aug. 10, 2004) B.C. fish farmers cry foul over U.S. labelling rule (July 12, 2004) Warm Springs tribal member Elmer Scott Jr. dips a fish net into the base of thundering Sherars Falls from a platform on the Deschutes River near Maupin, Ore., July 21, 2003. Net fishing goes back centuries in this Columbia River tribe, where fish such as salmon, sturgeon and lamprey eels make up a critical part of the tribe's diet and cultural heritage. (AP Photo/Don Ryan)

I ND E P TH : SA L M O N

Atlantic wild salmon stocks at historic low (June 3, 2004) Conservationists nurse young wild salmon (May 17, 2004)

Salmon

Scientists defend farmed salmon (Jan. 9, 2004)

The salmon family

Study raises questions about safety of farmed salmon (Jan. 8, 2004)

CBC News Online | September 03, 2004

Salmon are part of a family of fish called Salmonidae which includes salmon, trout, char, whitefish and grayling. Salmonidae live in cold-water ecosystems around the world. Many are threatened because they have a low tolerance for degradation of their habitat. The family evolved about 50 million years ago, five million years after the great extinction caused by the impact of an asteroid. Fish were the first to recover and became very abundant; the dinosaurs had been extinct for about five million years and large mammals were only beginning to evolve. Most modern salmonidae species evolved during the geologically recent ice ages, the main reason they prefer cold, clear water. Some scientists are concerned that climate change that is probably raising the water temperature could be a threat not only to salmon but to trout and other members of salmonidae. What is the difference between a trout and a salmon? That depends who's asking the question. Anglers have called fish either trout or salmon, based on appearance and habitat in each local area. For example, anglers will find rainbow trout (a true trout) and brook trout (a char) in the same stream habitat. Scientists and conservationists prefer to speak about "salmonids." Generally – although it's not true for all – salmon spawn once and die while trout go through a number of spawning cycles.

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Study confirms farmed salmon more toxic than wild fish (Jan. 8, 2004)

RELATED: CBC Radio's Quirks and Quarks : Fish Farm Fears (Jan. 10, 2004) C B C T V ' s Marketplace: Farm-raised salmon

EXTERNAL LINKS: CBC does not endorse and is not responsible for the content of external sites. Links will open in new window. PCBs in fish: Health Canada fact sheet

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22/03/2005 11:28 PM

CBC News Indepth: Salmon

http://www.cbc.ca/news/background/salmon/

Many – not all – salmon are anadromous, a term from Greek which mean "running up," and refers to fish that are born in fresh water, migrate to live in salt water, then return to fresh water to spawn.

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The steelhead, which is sometimes mistaken for a salmon, is actually a rainbow trout that has a similar lifecycle to the Pacific salmon. The steelhead migrates to the sea, but unlike the salmon, continues to live after spawning and returns to the ocean.

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Atlantic salmon (Salmo salar) The Atlantic salmon is found on the East Coast of North America, in northern Europe including the British Isles, Ireland and Scandinavia, and as far south as Portugal. The Atlantic salmon is also an introduced species that is thriving in some rivers in southern Australia. It is also used for fish farming on both coasts of North America. The Atlantic salmon is a member of the genus salmo, and the species solar, which means "the leaper." It is silver with small black spots. There is just one species of Atlantic salmon but genetic studies have shown that the salmon are what scientists are calling "river specific," adapted to the specific river system where they were born. Atlantic salmon are born in riverbeds in early spring and, depending on food supply, temperature and other local conditions, remain in the birth river for two to six years. Then, again in the spring, the young salmon, called smolt, leave for the ocean. Almost all Atlantic salmon, whether from North America or Europe, spend their lives in the ocean off southwestern Greenland. When they return to their birth rivers to spawn, it can happen anytime between April and November. Some Atlantic salmon never reach the sea. Their lifecycles takes them into deep, fresh-water lakes instead of the ocean. The ocean-dwelling salmon can weigh between four and nine kilograms. The ones that live in lakes seldom grow larger than four kilograms. The Atlantic salmon is the most popular species for fish farming or aquaculture and it is estimated that 98 per cent of the 300 million Atlantic salmon in the world are farmed fish. Pacific The Pacific salmon is most famous for its lifecycle; born in tiny streams far from the sea, the Pacific salmon spends the first part of its life in fresh water, then migrates down streams to rivers and spends most of its adult life in the open ocean. Then it returns to its birthplace to spawn and die. Most Pacific salmon are part of the genus Oncorhynchus from the Greek, meaning "hooked snout" – referring to the salmon's mouth. Recent research has shown that the cycle is key to much of the West Coast environment. The salmon's flesh is rich in oils that are picked up during its life in the ocean. That oil helps give the salmon the energy for the return journey upriver. It also feeds other animals like eagles and bears. The salmon remains and animal droppings provide nitrogen and other nutrients to the West Coast rainforest. There are five species of North American Pacific salmon:

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22/03/2005 11:28 PM

CBC News Indepth: Salmon

http://www.cbc.ca/news/background/salmon/

Chinook (Oncorhynchus tshawytscha) The Chinook is the largest of the West Coast salmon (they can weigh up to 55 kg) and is also called "spring salmon" or "king salmon." It has a bluish-green back with light spots and is a favourite catch for anglers. In Australia, where the Chinook is an introduced species, it is called the Quinnat salmon. Its found in southern rivers, but is dependent on stocking programs for survival. Chum (Oncorhynchus keta) Chum salmon, also called keta salmon, have silver sides, black spots and, often, faint stripes. One of the smaller salmon species, chum weigh up to 4.5 kg. Coho (Oncorhynchus kisutch) Coho are a bright silver, slightly larger than Chum salmon and weigh up to 6.8 kg, They are a popular game fish.

Pink (Oncorhynchus gorbuscha) Pinks are the smallest of the Pacific salmon, weighing up to 2.3 kg. They are silver with large, black spots. Pink are the most plentiful of the West Coast salmon and have a lower commercial value than other species. Sockeye (Oncorhynchus nerka) The sockeye is the most popular among the West Coast salmon with both anglers and commercial fishers and is reputed to be the best-tasting salmon. It is bluish-silver, and the most streamlined of the salmon. It weighs up to 3.2 kg. The kokanee, or sliver trout, is a land-locked subspecies of sockeye that never leaves fresh water. The Australian salmon (Arripis truttaceus) The Australian salmon are an ocean-dwelling species found along the south coast of Australia. Its silver with black spots and weigh up to 10 kg. The decline of the salmon population Salmon populations are declining on both the west and east coasts of North America. Scientists say the decline of Atlantic salmon began with the Industrial Revolution, as pollution contaminated the clear streams that salmon need. In the 1960s, the discovery of the Atlantic salmon feeding grounds off Greenland led to the commercial fishery concentrating on that area, devastating stocks. The North Atlantic Salmon Conservation Organization agreed to drastic cutbacks in the Greenland catch but the wild Atlantic salmon population has not rebounded and remains at about 3.5 million worldwide. Current estimates say that the number of Atlantic salmon in North American rivers is down to 80,000 and some scientists fear the wild species could become extinct. Some environmental activists and scientists also blame the decline of the wild Atlantic salmon stocks on rise of aquaculture on, saying that the farmed stock can spread disease to the wild salmon, especially infection by sea lice, which eat the fish alive. Some studies suggest that farm stock can escape from their pens and interbreed with the wild salmon and that offspring are less likely to survive in the wild.

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22/03/2005 11:28 PM

CBC News Indepth: Salmon

http://www.cbc.ca/news/background/salmon/

Stocks on the West Coast of North America are also in sharp decline. Some rivers in British Columbia that once saw salmon returning in their thousands now see a few hundred each season. Habitat degradation through both logging and farming is one factor. Scientists suspect climate change is warming both the ocean and river water and making it difficult for Pacific salmon to thrive or even survive. All the farmed fish on the West Coast are Atlantic salmon and environmentalists fear the spread of sea lice and other diseases from pens to wild stocks. In British Columbia and Washington state, there have been reports that escaped Atlantic salmon are establishing themselves in rivers where the Pacific species have declined. Generally both Atlantic and Pacific salmon stocks are stronger in areas far away from civilization, with higher numbers reported, for example, for Atlantic salmon in Labrador and for Pacific salmon in more isolated rivers in Alaska and British Columbia. A recent problem is the discovery of contaminants in salmon, including PCBs. The Canadian Food Inspection Agency says levels of PCBs in wild salmon are 1/80th of the acceptable levels established by Health Canada. PBDEs are a similar chemical to PCB, that's used in flame retardants. Health Canada says it's monitoring the situation but current evidence suggests that PBDEs in salmon do not pose a threat to human health.

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22/03/2005 11:28 PM