Dead Zones
Spread of the Dead Zones:
A world crisis
Dead zones have dotted the world's oceans since the 1950s, and have doubled every decade since the 1960s. Today, the world has 406 identified dead zones and counting. The outlook isn't pretty, as climate change is altering ocean circulation patterns in a way that will increase the number, size, and frequency of dead zones.
| Strait of Georgia |
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B.C. poised for more dead zones
In the Strait of Georgia, science models shows that oxygen levels will decline in the intermediate and deep ocean, and that we'll see an expansion of "oxygen minimum zones" – areas of severe low-oxygen that may lead to dead zones. But where and when remains a mystery.
Breathing life into dead zones: can the damage be reversed?
Once altered by a dead zone, an ocean ecosystem may never recover. But if we reduce the flow of nutrients like agricultural run-off, it's possible that some pollution-caused dead zones around the world can be improved.
For instance, the dead zone in the Black Sea expanded to 400 hectares (more than twice the size of Washington State) between 1973 and 1990. Fertilizer became more expensive to use after the Soviet Union collapsed, and by 1995, the dead zone disappeared because of a drastic reduction in fertilizer use. But as agricultural activity intensifies, the dead zone could creep back in.
Stop the dead zones! You can help!
If we want to prevent dead zones from blotting out marine environments in British Columbia and along the Pacific Coast, we need to address both pollution and climate change.
Healthy oceans need healthy waste management practices. This means preventing fertilizers and animal wastes from entering our oceans, and carefully monitoring septic and sewage systems.
As individuals, we can also help by reducing our carbon footprint – this means cutting back on our output of the greenhouse gases responsible for climate change. While our individual actions don't seem to amount to much, collectively they make a big difference. Find out how you can Take Action Every Day.