Hundreds of seabirds have washed up along the west coast of the North Island in the last month

The Department of Conservation says they died from starvation due to climate-change impacts.

It's thought to be due to unusually warm seas off the coast of Japan, affecting the birds' food stocks.

These include Sooty shearwaters, Buller's shearwaters and fairy prions, all dependent on conservation management to prevent further declines.