Wednesday, October 07, 2009
Salmon: global resource that is important to Canadians
Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce.
Freshwater streams and estuaries provide important habitat for many salmon species. They feed on terrestrial and aquatic insects, amphipods, and other crustaceans while young, and primarily on other fish when older, says Wikipedia.
Salmon is a popular food. Classified as an "oily fish", salmon is considered to be healthy due to the fish's high protein, high Omega-3 fatty acids, and high vitamin D content. According to reports in the journal Science, however, farmed salmon may contain high levels of dioxins. PCB (polychlorinated biphenyl) levels may be up to eight times higher in farmed salmon than in wild salmon. Nonetheless, according to a 2006 study published in the Journal of the American Medical Association, the benefits of eating even farmed salmon still outweigh any risks imposed by contaminants.
The population of wild salmon declined markedly in recent decades, especially north Atlantic populations which spawn in the waters of western Europe and eastern Canada, and wild salmon in the Snake and Columbia River system in northwestern United States.
- Overfishing in general.
- Ocean and river warming.
Salmon aquaculture represents over $1 billion US annually. Other commonly cultured fish species include: tilapia, catfish, sea bass, carp, bream, and trout.
Salmon farming is very big in Chile, Norway, Scotland and Canada and is the source for most salmon consumed in America and Europe.