Auckland Council says it is seeking advice on how best to get rid of slippery algae on rocks at west coat beaches that led to a drowning and several close calls.
Last week a 19-year old man was preparing to go fishing from the rocks at Muriwai Beach when he fell into the water and drowned.
In the latest incident a young man, also 19, slipped on rocks at the beach on Saturday and fell into the surf, but managed to save himself with the help of a friend.
Muriwai Lifeguard Service says recent growth of algal bloom has made the rocks as slippery as ice, and the problem needs to be fixed before the busy summer.
In statement, the council said it was taking advice on how to disperse the algae and is working with the lifeguard organisation.
It is warning people visiting west coast beaches to take care around rocks and says new alert signs have been erected and life rings put in place.