“What we’re seeing at the moment is the two large species of baleen whales, these are the humpback and southern right whale,’’ explains wildlife officer Cloe Cummings from the

Department of Primary Industries, Parks, Water and Environment’s Marine Conservation Program.

“We tend to start seeing them around May as they’re travelling north to calving grounds, and then we see them again as they head south to feeding grounds from mid-August to November. So we’re right at the peak of the season now.

“At the moment most of the pictures we are seeing, and a lot of the really spectacular acrobatic behaviour, is from the humpback whales.’’

Passengers on boat cruises, including the Pennicott Wilderness Journeys cruise to Tasman Island, have been delighted by the antics of whales in the past couple of weeks, with the curious creatures putting on a show for onlookers who were armed with cameras and have shared stunning photos and videos widely on social media.

Cummings says recent whale sightings have mostly been humpbacks. They are traditionally more acrobatic than southern right whales, but they also visit Tasmanian waters in far greater numbers.

About 60,000 humpbacks migrate through Australian waters each year, compared to only about 3300 southern right whales.

These whales form part of two different migratory populations – there’s a southeast Australian migratory population (those that migrate through Tasmanian waters as they head along the east coast of Australia towards NSW and Queensland) and the West Australian migratory population (those that migrate along the South Australian and WA coastlines).

There are about 30,000 humpbacks in each of those migratory populations, but when it comes to southern right whales the split isn’t so even.

There are about 3000 southern right whales in the WA migratory population but less than 300 in the southeast Australian migratory population, meaning that Tasmanians who manage to spot a southern right whale are particularly fortunate.

Marine Conservation Program staff such as Cummings keep a close eye on all whale movements in Tasmanian waters but they are especially interested in southern right whale sightings because they are far rarer – the southern right whale is considered to be one of Tasmania’s rarest mammals.

Cummings says it’s important that Tasmanians who spot whales – be it a humpback or a southern right whale – report the sighting to the Whale Hotline so that key information can be used to feed long-term data sets and help monitor trends when it comes to whale numbers and movements.

The whale hotline receives about 850 calls a year, but the number of calls obviously varies widely depending on the time of year, where whales are, how clear the weather is, and how many Tasmanians see them.

If there’s a whale in the River Derwent, for example – putting on a show for residents as one did a couple of weeks ago – calls to the hotline go crazy.

“It really ebbs and flows but we definitely have an increase during the whale migration season,’’ Cummings says.

We tend to get calls from all around the state. But if there’s a whale anywhere in the River Derwent, that tends to really fire up the hotline.’’

Hotline operators typically want to know basic details about the time and location of the sighting, as well as the type of whale, how many whales were travelling together and where they were headed.

“We generally have a bit of a chat to people when they call them in,” Cummings says.

“Some people know exactly what they’re looking at and are quite knowledgeable about whales.

“Otherwise we’ll talk them through and ask them to look for identifiable features, the number of whales, their direction of travel and any interesting behaviours as well.’’

Southern right whales are usually bigger and heavier than humpbacks.

They grow up to 18m and weigh up to 80 tonnes, while humpbacks usually grow up to 16-17m and can weigh up to 40 tonnes.

Humpbacks have a small dorsal fin, while southern right whales have a rounded back and no dorsal fin. Southern right whales also have a distinctive double blow.

Southern right whales have white callosities (white barnacle-like features) on their faces, distinctive markings which act much like a human fingerprint and allow researchers to identify and track individuals.

Studies are often conducted by air, with a catalogue of photographs showcasing the unique appearance of each whale.

And social media sites such as the Whale Spotting Tasmania Facebook page, which has almost 18,000 members, is also monitored for information, although Cummings encourages people who post sightings on the page to also call the hotline.

The Marine Conservation Program also works in partnership with other organisations such as the Institute for Marine and Antarctic Studies which is conducting a Tasmanian Whale Fluke Project, looking at the fluke (underside) of humpback tails to better understand the creatures.

Whale populations of both humpbacks and southern right whales were once decimated by whaling, which was a major maritime industry across Australia in the 1800s, with about 60 shore-based whaling stations once operating in Tasmania.

“The humpbacks have actually bounced back really well, they are a really good conservation success story,’’ Cummings reveals.

“Numbers have been increasing at about 10 per cent a year … and data suggests we’re pretty close to pre-whaling population numbers now.’’

Southern right whale numbers have also continued to climb since whaling days, but not at the same rate.

One of the many reasons for this is the breeding cycle of the whales.

After a summer of feeding on krill in Antarctic waters, humpback whales head north to subtropical waters where they give birth, mate again, and then head south (the direction they’re currently heading) with their calves to feed and repeat the process.

Cummings says southern right whales follow a similar pattern (although they tend to calve off the Victorian coast rather than in NSW or Queensland), however they don’t mate as often.

So while most female humpbacks give birth every year – and are usually pregnant as they swim south nursing their calves – for southern right females this is more like every three years.

The Tasman Peninsula, Binalong Bay, Great Oyster Bay, Adventure Bay, Frederick Henry Bay, Marion Bay and Recherche Bay are among some of the best places to see whales at the moment.

But, as Cummings knows only too well, “with all wildlife sightings, there’s an element of being in the right place at the right time’’.

Originally from Queensland, she remembers watching whales at Hervey Bay as a child.

She studied marine biology at the University of Tasmania and has lived in Tasmania for 10 years.

Cummings says living in a state surrounded by water, in the direct path of whale migration, it is easy to see why so many Tasmanians are fascinated by whales.

“Whales are just so charismatic,’’ she says.

“And I think for many people it’s just amazing to know there are these whole other lives going on under the water.

“You can be sitting (by the water) having your lunch and to see a wild animal going about its daily business is pretty special.

“Tassie is so amazing in that sense; there are a lot of people who can look out their window and see a whale or a dolphin.’’●

Whale sightings should be reported to the Whale Hotline on 0427 942 537 (0427 WHALES).

Tasmanians watching whales should also maintain appropriate distances –

visit dpipwe.tas.gov.au/wd-viewing for guidelines.