2016 Environmental Conditions for Salmon
In 2016, BC salmon, which thrive in cool water, are again likely to face less than ideal environmental conditions. Three key factors have influenced the ocean environment that BC salmon encountered during their migration. These include exceptionally warm ocean conditions due to “the Blob” and El Nino, reduced nutrient food sources such as warmer water planktons, and the presence of warmer water predators.
The warmest winter water temperatures ever observed (1948-2014) in the eastern subarctic Pacific occurred in 2014 and 2015 including record warm temperatures along the outer BC coast from October 2014 and continued through 2015. Warm conditions caused a change in species of plankton, from highly nutritious northern types to poorly nutritious southern types, and an increase in gelatinous plankton.
Salmon that went to sea in 2014 or earlier may not be significantly affected by the warm ocean conditions, until they arrive at river mouths. tThe extremely low snow pack levels in southern BC increase the probability of low river levels and high river temperatures this summer. Salmon generally hold at the river mouth while waiting for cooler conditions before they migrate upstream to spawn. But sometimes salmon do not wait long enough and swim upstream into lethal water temperatures. The adverse river conditions can reduce the number of salmon successfully reaching the spawning grounds.
The Department monitors and forecasts in-river conditions for salmon and takes this information into account when making fishery management decisions.
Outmigrating young salmon in 2015 and 2016 encountered warmer river temperatures and warmer-than-usual ocean conditions. Warm ocean conditions may be associated with poor quality prey species which can impact the growth and survival of these young salmon in the coming years.
Fisheries and Oceans Canada will continue to monitor salmon and ocean conditions in 2016 and 2017 to determine the impacts of these very unusual conditions on returning salmon.
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