Big seas have washed tonnes of seaweed on to Auckland beaches, triggering an explosion of tiny sandhoppers and raising fears the rotting weed will soon begin to stink.
Auckland councillor George Wood said on Facebook that Takapuna residents would be "aghast" to learn there were no funds available to clean up Takapuna Beach on the North Shore.
A council cleanup of the kelp could cost up to $50,000 and is unlikely, especially in winter.
But keen gardeners have spotted an opportunity to gather the seaweed to use as a mineral-rich fertiliser.
Wood wants periodic detention workers to clean up the seaweed and send it to the Devonport waste recycling centre for gardeners to collect.