In British Columbia’s Fraser River it has been reported there are an estimated 34 million salmon, up from just 1.5 million last year. Scientists are puzzled by the huge increase, but warn it is most likely not a long-term trend, and that next year’s run is probably not going to be at the same level. Professor Daniel Pauly, a local fisheries professor noted science is good at identifying long-term patterns, but not so good at predicting short-term events in some cases. This current huge influx appears to be one of those rare anomalies. Last year the numbers were abnormally low, so much so the Canadian government formed a panel to launch an inquiry.
One theory for the likely one-time salmon population explosion credits the eruption of a local volcano, which dumped large amounts of ash into the Gulf of Alaska where diatoms fed on its nutrients. A very enlarged diatom population provided copious amounts of food for young salmon, and their population surged in the presence of the food surplus. During the previous year, the 1.5 million salmon consumed their normal diet – plankton in a relatively limited supply.
The panel appointed to investigate last year’s very low numbers, has convened this week to discuss the situation. The Cohen Commission’s meeting has caused anti-fish farming protesters to gather near their building. They believe the long-term decline of wild salmon is due to disease spread by salmon in fish farms. The B.C. Salmon Farmers Association has also been vocal, through newspaper advertisements questioning the process considering the most recent enormous spike in wild salmon.
Professor Paul explained, this one-time blip in the salmon population should not be interpreted as an indication fisheries are on the mend, “The global picture is that we have lost 80-90 percent of the big fish. Biodiversity is being lost on a grand basis in the oceans and it is due mainly, overwhelmingly, to fishing.” (Source: BBC.co.uk)
He said most fisheries once in a while have a very strong surge for a year, but scientists are still not clear why they happen, and that they are not good indicators of the overall health of a fishery.
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