Migrating north from Antarctic waters where they have spent the summer months feeding on krill, they hug the east coast of Australia on their way to breed in the warmer waters of the Coral Sea.

Thousands of visitors flock to Nelson Bay between May and November each year to get a closer look at the majestic mammals. The whale-watching industry is vital to the region's economy. Destination Port Stephens says whale-related tourism contributed $621 million to the local visitor economy in 2019, which equates to an estimated $70,000 of revenue per hour.

Lisa Skelton, who works for Nelson Bay eco-tourism company Imagine Cruises, says it's shaping up to be a great season. On a 90-minute cruise last week, for example, passengers were treated to the sight of 50 or more whales.

"Right now people are looking for short breaks and self-drive options closer to home that still offer amazing adventure experiences and a sense of escape," she says.

"Also, reduced passenger numbers to allow for social distancing means people can enjoy a more personalised experience on-board vessels."

Skelton, who is also a wildlife photographer and advocate as well as a founding member of the Marine Parks Association, says about 2000 whales passed by Port Stephens about 25 years ago. Today that number is closer to 35,000.

Her interest in photography stemmed from her childhood love of whales and, yes, the movie Free Willy. In 2010 she travelled to the United States to tick the number one item off her "bucket list" - seeing killer whales in their natural habitat.

"It was a life dream to see them but at first glance I knew one encounter was not going to be enough," she says.

Skelton returned to the US the following year, visiting the San Juan Islands in Washington State.

"The southern resident orca which frequent the waters of the Salish Sea are perhaps the most famous and best known among the scientific community, providing a framework for many population studies of cetaceans around the world," she explains.

"The population is also critically endangered. Their numbers were decimated through the 1960s and '70s when many were captured and sent to aquariums, and since then they have contended with health issues thanks to high chemical build-ups of pesticides and fire retardants which found their way into the waterways - and through bioaccumulation - into the animals' systems.

"Today they contend with a dwindling food source as the numbers of chinook salmon - their staple diet -continues to decline."

Today, Skelton says, there are only 73 orca left in the southern resident population.

"Seeing these animals in the wild and understanding the challenges they faced made me appreciate how special each encounter with them was and that it shouldn't be taken for granted," she says.

"I decided I wanted to preserve my experiences as best I could. When I returned home from the US in late 2011, I went straight to the local Camera House and bought my first digital SLR camera."

The following whale season, in 2012, Skelton embarked on a whale-watching cruise at least once a week while studying a degree in music and education in Newcastle.

Plans to pursue a career as a high school music teacher were put on hold - indefinitely - when she secured work as a deckhand with Imagine Cruises and honed her photography skills.

"I haven't had any formal training for photography - I think having loved whales and dolphins from such a young age meant that I already had a good understanding of my subject, so anticipating behaviours was easy for me and I could focus more energy on getting the most out of the camera," Skelton says.

"I've also been lucky to have some great friends and mentors over the years who have helped me improve in leaps and bounds."

Her main focus over the past five years has been underwater photography. By sharing photographs on her website, Lisa Skelton Photography, and by working for Imagine Cruises she hopes to encourage people to develop a deeper connection with, and appreciation for, wildlife.

Skelton has some amazing stories to tell. She says she is drawn to whales and dolphins because of their "unique sense of culture based on their geographic location".

"The only other beings on this planet that I'm aware of that have that quality is us," she says.

"Killer whales have very different diets based on their family's preference for certain food types. Orca in New Zealand have a diet that consists predominantly of stingrays.

"The southern resident killer whales in the Pacific North West feed exclusively on salmon while another ecotype of killer whale exists in the same waters that feeds on marine mammals like seals, sea lions, minke whales and porpoise.

"Each ecotype has its own unique language and populations have been genetically distinct from each other for thousands of years."

While killer whales might look similar all around the world, she says, that's where the similarities end.

"The idea that you could know so much about a certain population and be a complete novice about a different population of the same species is fascinating. It's a testament to the level of intelligence of these animals and their complex social relations."

Humpbacks are also unique, Skelton says, in that the males perform elaborate "songs" specific to their population and geographical location.

"All males in a population sing the same song, which is rewritten each summer - think of it like a one-hit wonder," she says.

"It was thought the songs were used to attract females, although recent studies suggest it may be used by the males as a means of organising their relationships and determining if specific males co-operate or compete for females.

"The songs male humpbacks sing that pass our coast is very different to the tune humpbacks are singing in Hawaii. The song actually somewhat conforms to the western notion of song structure with a verse, hook lines and a bridge.

"It is even rehearsed the same way. When learning a new piece of music, musicians will isolate difficult phrases and practise those before playing them within the context of the piece. Humpbacks learn songs the same way."

Skelton is familiar with the 100 or so Port Stephens bottlenose dolphins because they don't migrate and tend to reside in the sheltered waters of the bay.

"We can differentiate between every dolphin in our population by looking at the dorsal fin. Each fin has different nicks and scarring that is unique to that individual and acts like a fingerprint," she says.

"Macquarie University did an extensive population study in the early 2000s and, since 2014, I have been doing my best to build on their work and maintain a census of the Port Stephens dolphins.

"Every dolphin has a unique number they are assigned as part of the cataloguing process but some of the dolphins that are seen more regularly that have very distinct features, or that are particular favourites of crew working in the industry, have received nicknames as well.

"Personally, I like how giving a dolphin a name allows you to more easily share stories of that particular animal with guests on cruises - it personalises the experience for each guest.

"Perhaps they saw Nicky, the oldest dolphin in the Port, who is estimated to be over 40 years of age and easily recognised by a large triangular notch in her dorsal fin.

"I hope that by sharing the stories of individual dolphins like Nicky people feel more connected to them and that when we then have discussions about things that impact these animals, like marine debris, people will relate more and may feel motivated to make small changes within their own lives to lessen their footprint."

With the exception of Migaloo, the famous all-white humpback whale, individual whales are more difficult to identify than dolphins, but humpbacks do have their own fingerprint of sorts.

"The pattern on the underside of the tail flukes is unique to each individual," Skelton says. "If you can take a clear photo of the underside of the tail fluke, it can be submitted to happywhale.com, a global catalogue of humpback whales which gives you updates every time 'your whale' in re-sighted."

Speaking of Migaloo, he has been sighted already this season.

"My first encounter with him was in 2014, and he actually breached while we were watching him," Skelton says.

"The odds of being on the water at a time when he is passing through are pretty low, and as just one of some 35,000 whales, he's a bit of a needle in a haystack.

"I think Migaloo is special because he really embodies how our perception of these animals has changed. There's the story of Moby Dick, the large white whale that was feared and hunted by whalers, and now we have Migaloo, this white whale whose life we celebrate as one whale in a population that was nearly driven to extinction."

Skelton laughs when recalling a particular dolphin memory. "With our resident bottlenose dolphins, I've had a couple of encounters when they have been playing with pufferfish," she says.

"The toxins of pufferfish are thought to cause a narcotic effect on the dolphin's brain, which could be likened to the effects of drugs like marijuana on our own. The dolphins don't eat or kill the pufferfish, they simply harass it and ingest a small amount of the toxins produced by the fish.

"It's very exciting and funny to watch."