Suffocating dead zones spread

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Critically low oxygen levels now pose as great a threat to life in the world’s oceans as overfishing and habitat loss, say experts.

Man-made pollution is spreading a growing number of suffocating dead zones across the world’s seas with disastrous consequences for marine life, scientists have warned.

The experts say the hundreds of regions of critically low oxygen now affect a combined area the size of New Zealand, and that they pose as great a threat to life in the world’s oceans as overfishing and habitat loss.

The number of such seabed zones