Most of the time, Libby Hall can patch them up and send them on their way. But the manager of Taronga Wildlife Hospital says the injuries can be prevented.

''We see everything from tiny frogs right through to large leopard seals and everything in between,'' Ms Hall says. Many of the animals treated at the hospital are injured by cars or cats and dogs. Others, such as owls and microbats, are affected by land clearing. But she attributes most of the recent ''dramatic increases'' in animal deaths and injuries, such as turtles and penguins, to marine debris.

''Marine turtles are endangered worldwide and one of the biggest threats is ingestion of plastic,'' Ms Hall says. ''I call it death by plastic.''

While plastic bags were a major problem, Ms Hall says ''there are pieces of plastic right through the animal's intestine''.

Other debris is also a problem.

''We see bottle tops, balloons are also common, as well as bait bags, rope, fishing line and fish hooks,'' she says. ''We are having great success treating marine turtles when we can remove the debris but small pieces of plastic are now everywhere in the marine environment.''

Taronga has been following the marine turtles with satellite trackers with some interesting results - it released a 110-kilogram green male turtle a couple of months ago and was surprised to see how far he moved up and down the coast.

''We have put trackers on juvenile loggerheads released from Lord Howe Island,'' Ms Hall says. ''No one knows where these animals go when they leave Australian shores until they return after what we call 'the lost years'. We are tracking them right across the Pacific and to the North Island of New Zealand. If we can work out where the hatchlings are going, we can perhaps influence fishing in the Pacific and reduce the number of juveniles that are dying due to bycatch.''

The community enjoys seeing turtles and penguins in the harbour. But for them to remain part of the marine world, the message from Taronga is a simple one: their environment needs to be preserved.

''Don't leave rubbish anywhere - it will be washed down in stormwater gutters and ultimately into the sea,'' Ms Hall says.

Regular patients at the Taronga hospital include juveniles orphaned when their mothers are killed on Sydney's roads. Wakehurst Parkway is one of the worst spots for road deaths, especially for swamp wallabies. Because their habitat is segregated, they are forced to cross busy roads, also a risk for bandicoots, wombats and echidnas.

''We also receive tawny frogmouths, powerful owls and peregrine falcons that have chased down prey - they get very intent on their prey and get hit by cars,'' Ms Hall says.

An important part of the hospital's role is community engagement.

''One of the great things about the wildlife hospital is that we involve the community - there is an educational component to the release of the animals,'' Ms Hall says.

''People who find the animal come in; they ring us almost every day to find out how the animal is going and then we involve them in the release of the animal so they become aware of its habitat.''

The rehabilitation process differs for every animal and could involve anything from a wing that may need to be pinned to a patient requiring a course of antibiotics or a round of physiotherapy.

Taronga Wildlife Hospital is well equipped to deal with a range of injuries, with its treatment room, operating theatre, laboratory and radiology. There are also intensive care, quarantine and rehabilitation areas for treating animals.

Ms Hall has tips for drivers who want to do their bit for animal conservation, beyond observing the speed limit. ''Native wildlife is very active at dawn and dusk. If an animal is feeding near the road it may stray onto the road so if a motorist slows down it reduces the risk.

''People throw food out of their cars which attracts animals to the roadside. We might think an apple core is OK because it is biodegradable but it attracts wildlife to the roadside where they will be hit.

''We can treat these animals [but] it would be better if they did not need to come to the hospital in the first place.''