The Department of Conservation is trying to track down the owner of a dog that attacked a seal at a Canterbury beach.

The small, white dog with ginger markings was filmed by a member of the public attacking a fur seal on the Pines/Kairaki beach.

Biodiversity ranger Anita Spencer says they want to speak to anyone who saw the attack or the dog and its owner in the area on Tuesday morning.

New Zealand fur seals or "keneo" are fully protected.

Last year three seals were killed by dogs on Christchurch beaches.