The mass tuatua die-off at Waihi Beach in mid-March was most likely due to the heavy swells the region experienced in the days leading up to the beaching.

This is the conclusion reached by the Bay of Plenty Regional Council, University of Waikato and the Ministry of Primary Industries which all carried out testing on the tuatua recently.

Thousands of the dead shell fish littered the north end of the beach, Sunlive reported at the time.

Following the mass die-off, a team of Bay of Plenty Regional Council and University of Waikato scientists ran a number of tests on tuatua samples found on Waihi Beach to determine their cause of death.

'Staff analysed samples of the shellfish for the presence of heavy metals, algal biotoxins and other indicators of contamination,” says BOPRC environmental scientist Rebecca Lawton.

'Results indicate that levels found in the samples were comparable to those recorded in live, healthy tuatua, ruling out contaminants as the cause of death.”

The MPI also analysed samples of the shellfish for evidence of disease, with results indicating bacterial or viral disease was not a likely cause of death either.

BOPRC scientists believe that although the images of hundreds of shellfish caused quite a bit of concern, Waihi Beach is still a healthy habitat for shellfish.