This duck was saved by Melbourne Zoo's crack team of rescuers. The Marine Response Unit had its prey. But they weren’t going to hurt it. They were going to save it. Melbourne Zoo’s animal rescue team – known by the callsign MZ MRU – is a crack squad of wildlife experts who save animals in distress. They responded to almost 500 calls this year, up 35 per cent. More and more, they find themselves dealing with cases just like this one: where a person’s careless, unthinking decision to toss a piece of plastic litter puts an animal’s life at risk.

Back at the zoo’s Werribee base, a vet reached one hand inside the cage and pressed down gently on the terrified duck’s back, so it did not hurt itself flapping. Then the vet gently eased off the blue plastic ring caught between the duck’s bill, and around its head. The ring – made for teething babies – had cut deep into the duck’s neck. It was one of a large number of animals trapped by plastic waste the team has rescued this year. Mark Keenan, co-ordinator of the Marine Response Unit Credit:Melbourne Zoo / Supplied Mark Keenan, who co-ordinates the team, says people don’t understand how much damage a piece of plastic can do.

“We see atrocious cases every year. People think it’s fairly innocuous, but when it’s wrapped around an animal that cannot remove it, it’s fairly tragic.” Loading About 3.4 million tonnes of plastic are used in Australia every year. Just 320,000 tonnes are recycled, meaning the rest ends up in landfill, or on streets and beaches and oceans. About 1.4 billion pieces of rubbish flow from the Yarra and Maribyrnong rivers into the sea each year, mostly microplastics. A survey by Keep Australia Beautiful found even the most litter-free areas of Australia averaged 200 pieces of rubbish per hectare. Among the items that cause the most injuries to wildlife are baseball caps.

Discarded at sea – or blown off in a strong wind – the caps’ fabric degrades in the water, but the sharp plastic band is left behind. “We have had several animals, seals in particular, caught up in hatbands. We have had animals nearly die,” Mr Keenan said. The rescues, themselves, are often extremely difficult. These are animals that are often panicked and in pain. “And you’re literally trying to catch an animal that evolved to avoid capture.” That’s partly why not all rescue attempts are so successful.

A darter with gauze wrapped on its beak. In September, Mr Keenan’s team received several urgent calls from people in the city. A young darter – a serpentine bird capable of swimming through the water like an eel and impaling prey on its beak – was flapping around the city, its face tangled in what looked like a strip of gauze, perhaps from a discarded bandage. When the team arrived, the bird had parked itself on a Yarra River rubbish trap near the Arts Centre. The team jumped into kayaks and headed for the bird. That’s where the trouble began.

Darters can fly. They can also dive, swimming at speed underwater for up to 60 metres. The hapless kayakers had no chance. “They are not an animal that will tolerate people,” said Mr Keenan. Eventually, he called his team off. Giving up is hard, but Mr Keenan knew they were just making things worse by stressing the poor bird. “Every time you try and catch an animal and fail, you make it that much harder next time,” he said. But then, a stroke of luck – the bird was somehow able to untangle itself, and was later seen happily fishing in the Yarra. Not every tale has a happy ending.