A family who took their dog into the Abel Tasman National Park, where dogs are prohibited, was fined $1200 by the Department of Conservation (DOC) after it killed a little penguin at Observation Bay.
They had taken their dog to the beach and it had gone into bush and returned with a penguin in its mouth.
Another person was fined $200 by the Tasman District Council for failing to control their dog after it pulled a penguin from its burrow at Tapu Bay, near Kaiteriteri. The owner sought vet treatment, but the penguin died 12 hours later.
DOC Motueka biodiversity ranger Leon Everett said owners were responsible for knowing where they could take their dogs, and for keeping them under control.
"It's a legal requirement for dog owners to carry a lead in public, even in an off-lead area. Dog owners should also be able to call their dog back straight away, not only to protect wildlife but also to keep their dog safe."
Everett said when on the beach, dogs should be walked on the wet sand to avoid little blue penguin burrows in cliff faces and rocky banks and to prevent disturbing shorebird nesting areas in sand dunes or around driftwood.
People should stay clear of groups of resting shorebirds to avoid stressing them.
"Little blue penguins are not only vulnerable when moving between the sea and their nests at dawn and dusk, but also while in their burrows.
"Penguins and other ground dwelling native birds can't escape dogs easily. It takes just a second for a dog to cause a fatal injury to a penguin so owners need to be attentive to their dog's behaviour and be able to recall them immediately if they're showing interest in wildlife."