What’s it like to be a cockle or a pipi when the sea turns to chocolate milk? Juveniles suffocate in even a thin layer of sediment, says Simon Thrush, head of the University of Auckland’s Institute of Marine Science. Adults “hold their breath” for a couple of days, then have to resume feeding—in water so full of sediment and pollutants it often kills them.
In thicker layers of mud, like here at Sandspit after January’s floods, even worms “just get stuck and die. It’s gruesome.”
New regulations introduced by Auckland Council in 2019 aimed to limit sediment from land development over the 12,000 building sites active each year. Last year, officers cited more than 82 per cent compliance—yet this summer of extreme rain events has defied all attempts to mitigate the runoff.