The rocky shore at the base of Leisure Island has been swamped by thick sea sludge.
Tonnes of the marine mess washed ashore and covered the rocks at Leisure Island and the rocky inlet facing Shark Alley.
The sludge was so vast it had spread across the lower half of Main Mount Beach.
Bay of Plenty Regional Council Tauranga Harbour programme co-ordinator Bruce Gardner said the sludge was about 95 per cent brown algae with small amounts of red and green algae mixed into it. He said the algae started washing up last week during the storm.
Neither Bay of Plenty Regional Council nor Tauranga City Council are planning to clean up the algae.
"The seaweed isn't causing any significant odour. As has been normal practice for similar deposits in the past, we will let nature take care of it," Mr Gardner said.