Water pollution has long been a threat to the Great Barrier Reef – plans to fix it aren’t up to the task

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When you think about threats to the Great Barrier Reef, coral bleaching due to climate change would likely be first.

But the world’s largest reef system faces many threats. One surprisingly large threat is poor water quality. When sediment is washed off farms, cities and bushland into rivers, it can be transported kilometres offshore. If there’s too much, it can smother corals and seagrass meadows. Fertiliser and pesticide residue can make things worse.