Department of Conservation officials are warning locals to steer clear, after recent sightings of a humpback whale and calf off the Tauranga coastline.

Tauranga biodiversity ranger, John Heaphy says as a protected species, locals need to keep their distance.

'All whales are protected so you must stay a minimum of 50m away and if they appear to have a calf, you must stay even further away so that you are not distressing or harassing that mother and calf bond.

'An absolute minimum is the 50m but we would encourage much more.”

Humpback whales, which are one of the larger baleen whales, are known to sift tonnes of water at a time through baleen platers in their upper jaw, which work as sieves that pick out and allow the species to feed on small crustaceans such as krill, says John.

'Humpbacks are migratory, they migrate north and south twice a year so they can come past the Bay of Plenty occasionally.

'In winter they give birth up in the Pacific Islands around Tonga and Samoa,” he says. 'After breeding they migrate down to the really rich waters in Antarctica in summer and then they migrate back up to the islands again in winter.”

He says the recent sightings are not too uncommon based on their migratory nature.

'They're becoming more common than they used to be, they nearly became extinct during the whaling era which stopped in 1964 but now, they are very commonly seen through their migration in the Cook Strait.

'That tends to their path of passing through rather than through the Bay of Plenty.

'During this time there are specific people who measure the amount of whales that pass through and they have seen numbers are slowly building back up.

'The Bay of Plenty however is not named like that for nothing, it is a very productive water – so we get a lot of whale species through here that may not be resident but tend to just be coming past.

'The whales that are going south at this time of year to feed, potentially if it's an adult female they could well have a calf, in that respect that is very special.

'This particular pair will be migrating down south – they might stay here for a while or they might shoot straight through.

'People should avoid that group completely.”

Other species of whales have also been spotted in the Bay of

Bay Explorer skipper, Brandon Stone says a rare moment was also witnessed on his charter recently when a minke whale was filmed swimming near their charter.

'We had just anchored and the whale swam around our boat for about ten minutes,” he says. 'They went right under the boat and all around and wouldn't go away, we were just having a BBQ.

'Minkes are not often seen but they love shallow water and they are quite inquisitive.

'We see quite a lot of whale species, bryde's whales, sei whales, killer whales which are actually dolphin species, pilot whales and false killer whales.

'Last season we've seen a lot of whales, but this is a first we've had one come to us while we've been anchored.

He says the whale was around 6m and quite small for a whale.

'They are incredibly fast and great hunters,” he says. 'When people see them we tell them to really enjoy what is such special moment and not just through a camera lens.

'We try to keep people calm, we try not to let them yell and tell them to be quiet, but the excitement usually just comes out.

'The law is to stay away from them, you're not allowed to swim with them and if they are feeding or calving you take greater care.

'There should never be more than three boats near them at one time so that they can continue doing what they need to, it's just common sense really.

'At this time of year they are usually nursing their young, resting and feeding, so it's really important to give them some space but don't be surprised to see them.”