SOON after the Russian tanker Nakhodka sank in the Sea of Japan on 2 January,
oil-soaked seabirds began to struggle ashore. Ancient murrelets, rhinoceros
auklets, red-breasted mergansers, Japanese cormorants, black scoters, red-necked
grebes and black-tailed gulls had all become victims of oil leaking from the
hulk. Two weeks and more than 5 million litres of oil later, Scott Newman
arrived in Japan to offer help in rehabilitating 200 oiled birds that had been
brought in to two makeshift treatment centres. The birds were not receiving the
best care, says Newman, a veterinarian from the Wildlife Health Center at the
University of California in Davis.
In California, treatment centres follow a strict protocol designed to give
oiled animals a fighting chance of survival. The first step is to remove the oil
by washing the birds with washing-up liquid and then rinsing them with a
high-pressure nozzle. The cleaned birds are then given fluids to rehydrate them,
and fed activated charcoal to absorb any toxic chemicals they might have
swallowed. Each bird is tested for anaemia and other physiological abnormalities
that show up in the blood, checked to see if their feathers are waterproof, and
ringed so that they can be identified after their release. In Japan, few of
these things were being done, and the seabirds were housed on hard floors,
causing pressure sores to develop on their feet. The first few 鈥渞ehabilitated鈥�
birds that the Japanese released were not ready to return to the wild, says
Newman.
But the relatively inexperienced Japanese learnt quickly. They translated the
Californian protocol and posted it on the Web, and now the country is better
prepared to set up a system for saving wildlife from future spills, says Newman.
鈥淭he Japanese were very receptive to new techniques and showed a lot of
enthusiasm,鈥� he says.
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Indeed, techniques for rehabilitating oiled wildlife have greatly improved
over the past 25 years and more people around the world are being trained in the
latest high-tech methods for saving oiled wildlife. But is it all worth it? Does
the rehabilitation of oiled birds and mammals contribute to the recovery of the
populations hit by a spill? Unfortunately, the answer is generally no. The
efforts in Japan to save 200 oiled seabirds will neither boost the number of
seabirds in the region nor help populations to recover from the disaster, which
in the immediate aftermath killed an estimated 20 000 seabirds. In fact, many
people who work with oiled animals admit that their work has little, if any,
direct conservation value.
Every bird counts
But they also believe that one day it will, as their methods continue to
improve. At the very least, they say, they could contribute to the conservation
of endangered species because if rare animals are caught by a spill then every
individual rescued will count. 鈥淲e鈥檙e still new at this,鈥� says Newman. 鈥淏ut I
think in the future we have the potential to make rehabilitation work well for
many species and it will be important to prevent extinction.鈥�
Preparing for disasters sounds prudent, but a growing number of conservation
biologists argue that although attempts at rehabilitation are well meaning, in
general they are a case of too little, too late. Rehabilitation makes people
feel good, but the cost far outstrips the benefits. There is still little
evidence that the small number of birds and marine mammals released back into
the wild survive for long or ever breed again.
Critics say it is time to tell the public the truth: rehabilitation of oiled
wildlife is not based on sound conservation science and may be giving people a
false sense of security. 鈥淲ashing birds gives people the impression that we can
mitigate oil spills, that we can fix the damage to the environment,鈥� says Dee
Boersma, a biologist at the University of Washington in Seattle. 鈥淭hat鈥檚 a very
insidious view because people think if we just wash more birds or do it better,
we could solve this problem. It鈥檚 a ridiculous attempt. If anything, it allows
the problem of oil pollution to persist and it drains away money that could be
used to improve wildlife conservation.鈥�
Nevertheless, techniques for caring for oiled birds and marine mammals have
come a long way. 鈥淚n 1971 little was known about the toxic effects of oil or
about bird rehabilitation,鈥� says Florina Tseng, a vet at the International Bird
Rescue Research Center (IBRRC) in Berkeley, California. 鈥淰ery few birds survived
then.鈥� At that time, biologists knew that oil disrupted the microscopic
alignment of feathers that provides seabirds with a kind of wet suit around the
body鈥攚ithout which the birds die from hypothermia鈥攕o the volunteers
who came to help focused on washing off the oil. But they were rarely successful
because they used cleaning solvents that were themselves irritating and toxic to
the birds. After the Standard Oil spill, when two tankers collided in San
Francisco Bay in 1971, the IBRRC washed 7000 seabirds. Only 300, or 4.3 per
cent, survived to be released.
Care has improved since then. Birds are now cleaned with gentle detergents,
and immediately given fluids. They are fed special nutritional slurries, and put
into net-bottomed cages that are springy enough to stop them developing pressure
sores on their feet. Staff at the IBRRC have also learnt the importance of good
ventilation. In 1991, after the Tenyo Maru tanker sank in Neah Bay near the
border of Washington State and Canada, almost 80 per cent of 700 seabirds
treated died in captivity from a lung infection caused by the fungus
Aspergillus. Tseng blames the deaths primarily on poor air exchange.
Equally important, wildlife vets now understand much more about the toxic
effects of oil. The volatile components burn the eyes and skin and can trigger
pneumonia if they get into the lungs. When birds preen, they swallow oil from
their plumage. Once the hydrocarbons get into the bloodstream, they damage red
blood cells, which become misshapen and lose their ability to carry oxygen. This
not only limits a bird鈥檚 ability to dive for food, leading to starvation in the
wild, but it also puts a strain on the liver, spleen and kidneys as they
struggle to remove the damaged red blood cells from the circulation, says
Michael Fry, director of the Center for Avian Biology at the University of
California at Davis. In addition, exposure to polyaromatic hydrocarbons in oil,
combined with the stress of the disaster, causes immune suppression and
interferes with the reproductive system.
Suffering sea otters
Less is known about the toxic effects of oil on marine mammals, but sea
otters, which must constantly groom their fur to prevent hypothermia, suffer
from many of the same health problems as seabirds, with the extra problems of
emphysema and gastrointestinal damage. Seals are less at risk, because they do
not need to groom themselves constantly to stay warm and so are less likely to
swallow oil. Suckling pups may take in some oil if their mothers are
contaminated, and there is some anecdotal evidence that when seals breathe oil
fumes they become sluggish, possibly as a result of damage to the nervous
system.
With an improved understanding of the toxicity of oil, wildlife vets have
developed a set of medical tests that provide snapshots of the health of their
animal patients, from admission to release. Analysis of blood chemistry allows
vets to build up a picture of whether an oiled bird or sea otter is suffering
from anaemia, liver and kidney problems, stress or immune suppression. The tests
help them to decide at the start whether an animal is likely to be saved. Later,
after treatment, they indicate whether an animal is fit for freedom.
These improvements in wildlife medicine have generally increased the survival
of oiled wildlife in captivity, although the numbers that have made it back into
the wild still vary tremendously. Release rates reported by IBRRC for spills in
the 1990s that hit large numbers of birds range from 21 per cent at the Tenyo
Maru spill to 95 per cent after the spill from the Iron Baron off the coast of
Tasmania in July 1995. Success rates do not depend entirely on medical
technology, but are also heavily influenced by the species hit by a spill, the
number of individuals brought in at any one time, the kind of oil and the
weather conditions. In good weather, birds and other oiled animals can be picked
up quickly, while they are still relatively strong. Bad weather can delay rescue
operations until they are too weak to stand much chance of recovery.
Despite these uncontrollable factors, more seabirds do seem to be surviving
the rehabilitation process. Release rates are more likely to average 50 or 60
per cent these days, says Tseng. In future, as new care techniques become
standard and better facilities are built, even higher percentages of oiled birds
should live to see freedom, says Jonna Mazet, director of the Oiled Wildlife
Care Network, a programme run jointly by the California Department of Fish and
Game and the University of California at Davis to prepare for future oil spills.
鈥淲e鈥檙e doing things differently now,鈥� she says. As part of a law passed in 1990,
California established an oil spill response fund with fees collected from the
oil industry. Interest from the fund is paying for a network of treatment
centres for oiled animals.
Longest survivors
Treating wildlife with high-tech medical care may increase the number of
animals that survive the rehabilitation process. But do those released survive
in the wild? For the most part, no one knows, but biologists point to South
Africa鈥檚 penguins as examples of long-term survival. South Africa鈥檚 Cape region
is a hot spot for oil spills, with three major spills in the past three years.
The colonies of African penguins living around the Cape are regularly drenched
with oil. Since 1968, oiled penguins and other birds have been taken to a rescue
station in Cape Town run by the South African National Foundation for the
Conservation of Coastal Birds. The South Africans have documented sightings of
penguins that were cleaned and ringed 22 years ago. Tony Williams, of Cape
Nature Conservation, the provincial state authority, says: 鈥淣ot only are we
rehabilitating the birds, but we have evidence that a substantial number are
entering the breeding population. From a conservation point of view, that鈥檚 the
most important thing for this vulnerable species.鈥�
However, many conservation biologists point out that these birds are a
special case. Unlike most seabirds, penguins have a thicker layer of fat to
protect them from hypothermia, and they tend to haul themselves out of the water
when oil strikes, reducing their exposure and making them relatively easy to
capture. Other species are neither as robust nor as easy to deal with. For
instance, great northern divers and their relatives鈥攐r loons, as they are
called in North America鈥攁re extremely vulnerable to cold and rarely come
ashore. And because they cannot stand on dry land, they do very poorly in
captivity, says Tseng.
Clean but not cured
Such delicate species are likely to have high mortality rates when returned
to the wild. In a study that must have caused many a volunteer to lose heart,
Brian Sharp, an ornithologist based in Oregon, found that rehabilitated
guillemots, grebes and scoters had dismally low life expectancies in the wild.
Released guillemots lasted an average of just 9.6 days (This Week, 9 March 1996,
p 5).
A more recent study, published last autumn, found that brown pelicans
released in 1990 and 1991 failed to thrive. Daniel Anderson, a biologist at the
University of California at Davis, tracked 112 rehabilitated pelicans with the
help of radio transmitters, and found that between 12 and 15 per cent survived
for two years, in contrast to 80 to 90 per cent of non-oiled pelicans. The
stress of captivity may have had some effect on their survival, but pelicans are
鈥渕ellow birds鈥�, says Anderson, so it is more likely that they were suffering
some lingering toxic effects of the oil鈥攑erhaps suppression of the immune
system. Just as worrying, Anderson found that the pelicans steered clear of
breeding sites.
Investigating survival in the wild is difficult because researchers must
determine whether 鈥渕issing鈥� animals have died or just gone somewhere else, but
most say that more studies like Anderson鈥檚 are needed to see if rehabilitation
is really worth the high price tag. The biggest bills piled up during the Exxon
Valdez oil spill in 1989, when 357 sea otters were brought in for treatment.
Nearly a third of the otters died in captivity, 25 were given to aquariums
because they were not healthy enough to be released, and 197 were returned to
Alaskan waters. Each survivor cost Exxon more than $82 000. But even
those otters probably did not live long. Radiotracking studies of 45 of the
released sea otters found high rates of mortality. Eight months later, 12 otters
were dead and nine were missing.
鈥淓xxon decided to throw a bunch of money out there and trust the agencies and
professionals to tell them what to do,鈥� says James Estes, a marine ecologist
with the Biological Resources Division of the US Geological Survey in Santa
Cruz. 鈥淔rom a conservation and population perspective, there鈥檚 not much evidence
that any of the rehabilitation efforts were useful.鈥� Around 1600 seabirds were
also captured and treated. Half were returned to the sea at a cost of nearly
$32 000 per bird. After assessing the efforts in Alaska, the Pacific
Seabird Group concluded that rehabilitation is generally labour-intensive,
costly, has a low probability of success and could give the public false
perceptions about the real impacts of spills.
Penguins come cheaper
But those who try to save oiled animals say it is unfair to write off their
efforts because of the high costs in Alaska. Because Valdez was so remote,
everything had to be built from scratch, boats bought or hired and experts flown
in. According to Williams in South Africa, it cost just $600 for every
penguin rehabilitated after the spill from the Apollo Sea in 1994, although that
may be primarily because wages are much lower in South Africa. Wildlife
specialists also say that costs will fall as states and countries prepare
contingency plans for rescuing wildlife, including rapid-response teams and
permanent high-quality treatment centres.
But in many cases, rehabilitation may never be a feasible option. For
example, Magellanic penguins in Argentina are commonly oiled and would respond
relatively well to rehabilitation, but they migrate over 1600 kilometres. 鈥淵ou
could have a rehab centre in Argentina and the birds get oiled in Uruguay,鈥� says
Boersma, who studies the penguins. 鈥淲e simply don鈥檛 know where the next oil
spill will be.鈥� Added to this, many parts of Argentina鈥檚 coastline have no roads
or any supplies of freshwater for washing the birds.
Nor can rehabilitation help those animals suffering from the subtle effects
of chronic low-level oil pollution, which some researchers believe is a bigger
threat to wildlife than the headline-grabbing spills. Studies of mink, which
are related to sea otters, show that they breed less successfully after exposure
to low doses of oil. 鈥淭he most dramatic effect was a significant decrease in
reproductive capabilities鈥攁nd that lasted at least two generations,鈥� says
Mazet, who carried out the study.
Nevertheless, Mazet is a firm believer in rehabilitation. With new blood
tests and new treatment centres in California, she believes there will be a
noticeable improvement in survival in the next five or ten years. Yet
conservation biologists remain sceptical. Sharp says the people who encourage
and fund wildlife rehabilitation are participating in a large-scale deception,
which allows oil companies, government bureaucrats, salaried researchers and the
public to feel they are fixing the problem when in reality the birds and sea
otters are dying.
鈥淩ehabilitators keep saying wait a little longer, we鈥檙e getting better. But
they鈥檝e been saying this for thirty years, so how long should we wait?鈥�
Even if rehabilitation proves ineffective as a conservation tool, some argue
it is still important. Once animals are oiled, humans have a moral obligation to
provide the creatures with top medical care. 鈥淚鈥檓 philosophically opposed to the
idea that we only deal with wildlife on a population level,鈥� says Fry. Moreover,
he says, the responsible parties must be made to pay, and 鈥淚 don鈥檛 care what it
肠辞蝉迟蝉鈥�.
The philosophical gap between those who think wild animals should be treated
as individuals and those who think we should focus on the health of populations
may never be bridged. But public sentiment may be on the side of the
individuals. As the experience in Japan recently showed, people will pick up
oiled seabirds and try to save them whether they know how to help them or not.
鈥淚 don鈥檛 think there鈥檚 any way to make people turn their backs on animals that
are suffering,鈥� says Terrie Williams, a wildlife physiologist at the University
of California at Santa Cruz. 鈥淭he rehabilitation response is largely fuelled by
public empathy.鈥�
Critics argue that it would be far better to invest more in basic
conservation projects. The Pacific Seabird Group recommends more support for
controlling introduced predators such as foxes, banning gill nets that trap
diving birds, restricting public access to breeding islands and restoring
habitat.
The one thing both camps agree on is that the top priority should be to
prevent oil spills from happening in the first place. But that is probably even
more difficult. 鈥淚t鈥檚 a very idealistic thing to say that we should only put
money where it matters,鈥� says Estes. Tighter regulations on the shipping
industry, stiffer enforcement of laws to prohibit dumping, and campaigns to
reduce the public鈥檚 appetite for petroleum products would probably never be as
popular as caring for oiled wildlife.