Thousands of dead fish around Kawau Island in Hauraki Gulf off Auckland coast

Thousands of dead fish have been seen washing up on a Hauraki Gulf island.

Photos and video of what appear to be dead mackerel floating in the water and lining the shores of Kawau Island have been sent in to the Herald.

Dead mackerel lining the shores of Kawau Island. Photo / File

A reader told the Herald locals were cleaning up trailer loads of fish from the beaches.

A Department of Conservation spokesperson said he had spoken to two rangers about the dead fish.

"The word is it was a variety of fish and MPI are aware of it and investigating," he said.

Dead mackerel in the water surrounding Kawau Island in the Hauraki Gulf. Photo / Supplied

The Herald has contacted the Ministry for Primary Industries for comment.