The "senseless" shooting of a fur seal found dead on Stewart Island last week has angered The Department of Conservation.

A fur seal found shot on Stewart Island.

An adult male seal was found by trampers on Smokey Beach at the northern end of Stewart Island last Thursday.

It had a single hole in its side, suggesting it was shot with a rifle at close range.

"It's deeply disappointing that someone would deliberately and callously shoot a fur seal like this," says Jo Hiscock, DOC's Conservation Services Manager.

The seal is the third to have been shot since May this year. It is against the law to kill or harm fur seals and anyone charged with the offence faces up to two years in prison or a fine of up to $250,000.

Ms Hiscock said the trampers who found the seal couldn't understand why someone would commit such a "senseless killing".

"This incident and recent seal and sea lion shootings in other parts of New Zealand have highlighted that we need the public to help us safeguard vulnerable marine mammal species," she says.