The announcement, after years of planning and consultation, will expand the protection of creatures such as the blue whale, green turtle, critically endangered populations of grey nurse sharks, and dugongs, pictured.

Sydney - He's three metres long, weighs as much as a small fishing boat and can eat the combined weight of two small children every day.

But “Dhyum the Dugong,” the main character in a new children's book, has pressing issues on his mind. He wants to teach people how to save dugongs, endangered sea mammals, like him.

Dhyum is the creation of Australian scientist Mariana Fuentes, who decided to use a children's picture book to teach children and their parents about protecting dugongs, which some experts say are the source of mermaid tales.

“I think that through reading the book, kids can educate their parents about what they learned. Parents can often listen to their kids more than any researcher or government industry,” Fuentes said.

Dugongs are massive sea creatures which are related to manatees and can weigh as much as 500 kilos. They are found from Madagascar to Vanuatu, and in the wild can live up to 70 years.

Fuentes, a marine biologist at the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Queensland, spent three years researching dugongs for the book, which explains what they are and the dangers they face.

“Even though we follow cultural protocols, sometimes the whole community doesn't get the message, so I thought it would be a good way through the book,” she said.

Dhyum's home is the Torres Strait, a 35,000 square kilometre stretch of water between Australia and Papua New Guinea which is the home of the world's largest population of dugongs.

The book is aimed at seven and eight-year-olds and uses colourful pictures and a simple narrative to tell the story of Dhyum and his fellow dugongs as they eat, frolic in the ocean and deal with dangers such as pollution, being tangled in fishing nets, and overfishing by some indigenous cultures.

“Dugongs have important roles in the ecological system. The main role is through grazing sea grass beds in shallow waters, which reduces the risk of algae dominating the marine environment. One dugong can eat 30 kilos of sea grass a day,” Fuentes said.

Tracking a Torres Strait dugong involves three people jumping on the creature, placing a lasso around its tail and bringing it closer to the boat to insert the tag.

Dugongs play an important role in maritime culture for the Aboriginal and Torres Straits Islanders who live along the Great Barrier Reef. In respect of their beliefs Fuentes is not permitted to tag the creatures.

“In Torres Strait there are a lot of cultural protocols we have to follow, and one of them is that women are not allowed to catch dugongs,” she said. “It's always funny to see people trying to jump on the dugong and try and grab it. It's like a rodeo technique.” - Reuters