"The actual weed was on the beach a month before Christmas, 300mm to 400mm deep - just a carpet on the beach," he said.
"Council should have acted sooner - they should have had a tractor clear the area. The weed could have then been used for compost."
But Whangarei District Council waste and drainage manager Andrew Carvell begs to differ.
"The problem was caused when sand washed into the stream with the seaweed and algae and blocked the shallow entrance so the seaweed couldn't wash back out to sea.
"The trapped seaweed and algae then started to rot, turning the water black, which caused it to heat up quickly during the hot days, accelerating the rotting process," Mr Carvell said.
"Removing seaweed from the beach would not have made a difference, and council can't remove seaweed from beaches without resource consents, because of environmental issues."
Mr Hirst said most Cove locals had had no idea where the smell was coming from until they read about it in the Northern Advocate.
"It's a prime tourist attraction - they've got to be more pro-active."
He believes council should dredge it, as well as use portable compressors and aerators which are often used to help clean polluted rivers.
Mr Carvell said opening up the channel "at the peak of the problem would have let the black water run down the beach through swimmers so that option was ruled out".