SIMON O'CONNOR/Stuff New Plymouth's Back Beach is one of four beaches in the region off limits to swimmers and shellfish gatherers this anniversary weekend due to high levels of bacteria. Health warnings have been put in place at four Taranaki beaches by the Taranaki District Health Board Public Health Unit at the start of the regions anniversary weekend holiday. The four beaches are Ohawe, Back Beach, Ngāmotu Beach and Waitara West. The warnings follow sampling of seawater from the beaches March 1 which returned high levels of the risk indicator bacteria enterococcus, Taranaki DHB chief medical advisor Dr Greg Simmons said.