“Shark sightings usually peak over spring and summer as more people head to the beach and several coastal shark species move inshore to pup and feed on abundant inshore fish,” he said.
“During this period, calm conditions and cleaner water also makes sharks easier to spot.”
Mr Duffy said more sharks in the water should not, however, deter people from enjoying the warm water, despite an Oamaru teen who was bitten by a shark this week.
“Sharks are predatory animals but do not normally perceive humans as prey,” Mr Duffy said.
“Most encounters between humans and sharks do not result in bites.”
He said New Zealand had one of the lowest shark attack rates in the world, with only 25 fatal attacks recorded since 1840. The last fatal shark attack occurred at Waihi Beach in 2020.
“The harbour is a part of a shark's natural habitat. It is important for visitors to understand that there are always sharks around our coastline, and at times they may come close to the shore. It is not unusual for them to be there.”
Mr Duffy said 66 shark species were found in New Zealand waters, most of which were rarely-seen deep water species, and many were threatened or endangered internationally.
Great white sharks are protected under the Wildlife Act 1953. This means it is illegal to hunt, kill or otherwise harm them.
“While it's not illegal to accidentally catch a great white shark, it's a legal requirement to report it, and reporting captures of great whites helps us better understand the species and its movements,” he said.
DoC says if people are swimming in the ocean, they always need to be vigilant and swim where there are surf lifesaving patrols, and not to swim or dive alone.
“If you are heading out on the water exercise caution and avoid swimming in the main channels, or belaying from kayaks and jet skis when fishing.”
