There isn't much he can do about it apart from ringing the alarm bell, but Houhora Harbourmaster Greg Gemmell is becoming increasingly concerned by great white shark sightings in and outside the harbour.
Sharks, which he described as big and "rather hungry," had been seen more than once by people who know what great whites looked like, he said.
Mr Gemmell told the Northland Age yesterday that he had heard of three separate confirmed reports last week alone. Given the number and geographic spread of sightings he doubted that it was a solitary shark, but more likely a family of them, and quite a big family at that.
"It's a bit of a concern," he said, adding that he had seen video of a great white leaping from the water near the fishing club boat ramp, a popular swimming spot with children.
A local resident had also seen one while swimming in the harbour, north of the commercial wharf.
A local who had been fishing at the harbour entrance, and wondering why he was hooking fish but losing them before he could get them to the surface, used a go pro camera to look into the water, found a great white lurking beneath his boat.
A great white had launched itself out of the water in close proximity to a surfer at Rarawa Beach or Henderson Bay (he wasn't sure which), and they had also been seen off Kowhai Beach.
Those who persisted in dumping fish frames at the heads might have something to do with it, he said. They certainly wouldn't be helping, but all he could do was make people aware of the sharks' presence, and potential threat.
He noted that the great white shark was a protected species.
Mr Gemmell had reported the sightings to the Northland Regional Council, which might erect warning signs at some point, but in the meantime he wanted the local community to be aware of their presence.
"Please be aware and alert if you are near the water, and report any sightings to me," he said.
* Mr Gemmell can be contacted on (027) 651-7048.