Porirua eagle ray deaths most likely caused by stormy weather, not exotic disease, MPI says

Exotic pests and diseases have been ruled out as the cause of a mass death of eagle rays found washed up on the shores of Porirua Harbour.

About 20 dead eagle rays and two rig sharks were discovered by volunteers from the Wellington Coast Clean-Up Crew during a beach clean-up late last month.

At the time, the Ministry for Primary Industries (MPI) said recent stormy weather was the most likely explanation for the deaths, but testing was needed to rule out disease.

On Thursday, MPI confirmed laboratory testing found no evidence of exotic pests or diseases in samples collected from the animals.

Specialist staff visited the site to collect samples, which were analysed at an animal health laboratory.

MPI said the animals showed no signs of disease. Their stomachs were empty, but they were otherwise in good body condition.

The ministry said stormy weather remained the most likely cause of the deaths.

The dead rays and sharks were discovered by volunteers from the Wellington Coast Clean-Up Crew during a clean-up of the Porirua Harbour shoreline.

The discovery prompted an investigation by Biosecurity New Zealand's aquatic health team, while the Department of Conservation said it would not be involved because the affected animals were not protected species.