He has been out surfing off Shipwreck Bay for a while and said he had never seen a seal being attacked.
Department of Conservation spokeswoman Abigail Monteith could not confirm whether an investigation was under way but reminded the public to call 0800 DOC HOT so the mammals' injuries could be attended to and for DoC to also have a better chance of following up with owners of dogs responsible for the attacks.
It is an offence under the Marine Mammals Protection Act 1978 to disturb, harass, harm, injure or kill a seal and Monteith said a dog owner whose dog attacked a seal could face prosecution.
The offence attracts a fine up to $10,000.
"Overall, we have had great public behaviour in Northland around seals who are often close to shore or on beaches or inland this time of year. There aren't specific seal signs on beaches."
The Shipwreck Bay attack comes just over a month after DoC advised the public to admire fur seals/kekeno from a safe distance, as the mammals come ashore for the winter.
Between May and September, young seals and male seals of any age can be spotted as they leave their breeding colonies, explore and rest.
This includes newly weaned pups finding their way in the world. Kekeno are most often found on rocky shores but are curious and exploratory by nature and can be seen all around the coast in unusual places. They occasionally travel up rivers or as far as 15km inland.
Although very charismatic, kekeno were wild animals, DoC said, and should be treated with respect.
DoC has a hands-off approach with seals and will only intervene if the animal is in obvious danger such as getting too close to a road, tangled in debris, being harassed at a public beach or is seriously injured.
Sneezing, coughing and crying are all normal seal behaviours. Pups may be left alone for days at a time while their mother forages at sea.
DoC's advice is to never touch or handle a seal as they can be very aggressive if threatened.
If you encounter a seal on or near a beach:
• Always keep dogs on a leash, under control and away from seals
• Ensure you keep small children at a safe distance and under your control when watching seals
• Do not get closer than 20 metres
• Do not get between the seal and the sea
• Do not touch or feed the seal