Acid Deposition

Impact of acidification on Atlantic salmon

Status of salmon rivers in Nova Scotia, 1996
Map: impact of acidification on Atlantic salmon. Click for graphic description (new window).
Source: adapted from Watt et al., 200028

Despite having the lowest rates of acid deposition in eastern North America, the Atlantic Maritime Ecozone+ has some of the most acidic waters due to the poor buffering ability of the terrain.29, 30 There has been no measurable change in pH despite declines in sulphur dioxide emissions. This has resulted in the most heavily impacted fish habitat in North America.29 Atlantic salmon are highly sensitive to acidity, and by 1996, 14 runs in coastal Nova Scotia were extinct because of water acidity, 20 were severely impacted, and a further 15 were lightly impacted.28 Recovery of water chemistry and ecology is expected to take several more decades in Nova Scotia than in other parts of Canada.28-30

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