By Alison Ballance
Four hundred litres of freshwater, lots of Dawn detergent, and much time and effort. That is what it takes to clean up a single bird that has come into contact with oil from an oil spill. Multiply that four hundred litres by hundreds of birds and you’re talking a lot of water.
Members of the National Oiled Wildlife Response Team at Wildbase, at Massey University, are front-line responders when it comes to looking after wildlife following an oil spill. They have their equipment and trained staff ready to mobilise anywhere around New Zealand if they’re needed. Almost four years ago, when the container ship Rena ran aground on Astrolabe Reef near Tauranga, the Oiled Wildlife Response team led efforts to clean and rehabilitate more than 500 oiled little blue penguins and other birds. Hayley Pearson says that they were lucky’ when it came to the penguins “as they’re a hardy little bird”, and 95% of them were successfully rehabilitated.
But not all birds are so hardy, and when it comes to wildlife, oil is often deadly. More than 2000 birds died as a result of the Rena spill.
“Oil is quite debilitating for animals,” says Louise Chilvers. “It smothers them, it can cause them to drown, it can cause them to freeze to death. It affects their ability to thermoregulate [and maintain their temperature], and obviously it can get in to the food chain and they can eat it as well.
While big events such as the Rena disaster are a rare occurrence, Louise says that small fuel spills, such as a diesel spill at a marina, are almost a weekly occurrence.
The rehabilitation process for an oiled bird begins on the beach with people looking for affected animals. The birds are taken to wherever the rehabilitation centre has been set up and goes through a triage process to determine if it is likely to survive. Birds that are too bad are euthanized, while the others are taken to a vet to be stabilised and given food and fluids as necessary.
Then the wash-rinse-dry process begins. This takes warm water and lots of Dawn detergent, which many studies have shown is the best option; unfortunately it is not available in New Zealand, and the unit has to go to great lengths to import stocks of it.
“The bird is moved through lots of buckets,” says Hayley, “and it is washed with 200 litres of warm water that has been softened to remove any particles that might affect the bird’s feathers. It takes between 20-40 minutes to wash one bird.”
“Then we have to do a very thorough rinse process, as the detergent can be just as harmful to the feathers as the oil, by disrupting its structure.”
Next the bird is taken to warm, quiet environment, where it is allowed to preen naturally, and can recover its composure after what has been a stressful few hours. Over the following few days the birds are allowed out into a swimming pool to exercise for a few hours at a time, and this is an opportunity for the team to observe the birds and check that their feathers have become waterproof again. When the birds are judged to be fully waterproof they are released back into the wild.
During the Rena disaster the National Oiled Wildlife Response Unit had the use of a large area next to a waste water treatment plant in Tauranga, and there was a plentiful supply of freshwater on hand. But the Unit was concerned about how they’d cope in a more remote area with no ready supply of freshwater. So they embarked on an experiment, so see how well saltwater would work instead. Their ethics approval allowed them to use a domestic flock of ducks, and the ducks were dipped in oil, and then put through the usual wash-rinse-dry cycle, but using saltwater rather than fresh. They were pleased to discover that it worked as well, although it took more water to achieve the same result, and the salt crystals in the water caused the birds to look a bit scruffier for a few days until their preening got their feathers to right once more. Louise and Hayley report that all the ducks recovered well and were returned to their rural lifestyle block.
‘Best practise’ for treating oiled wildlife will continue to be freshwater, but Louise and Hayley say it is great to know that they could clean oiled animals using saltwater if they needed to - but, as always, they are hoping their skills and equipment won’t be called on any time soon.