Another lake in the Far North has succumbed to algal bloom, with health warning signs going up at Lake Waiparera, north of Kaitaia.
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Northland Environmental Protection Society president Fiona Furrell said the bloom was entirely preventable.
"Cattle graze both the DoC reserve and the council strip margin surrounding the lake, and cattle sunbathe themselves and cool off in the lake regularly. So if cattle defecate in a perched lake, that's exactly where it stays, because there is no river to flush that lake."
Ms Furrell said the Department of Conservation and the Far North District Council never bothered to fence the land around the lake.
I think the answer here is obvious: keep the cows out. But its a little late for Lake Waiparera.