Scottish scientists are this week preparing proposals for a massive
programme of research to monitor the scale of the environmental disaster
on Shetland, caused by the wrecking of the Braer, carrying 84 000 tonnes
of crude oil, during storms last week. Proposals from Scottish Natural Heritage
will include projects on everything from birds, marine invertebrates and
sea mammals to fallout of droplets of oil on heathlands, sheep and even
But, as debate continues about the true scale of the disaster, some
scientists are warning that efforts to save birds, otters and seals may
be increasing the potential damage to fish, invertebrates and plants.
The fallout onto the land of oil, sometimes mixed with chemical dispersants
sprayed onto the slick, has found scientists critically short of data on
the importance of this new phenomenon. After searching computer databases,
Victor Breeze of the government’s Long Ashton agricultural research station
near Bristol said: ‘There is no research done anywhere into the impact of
hydrocarbons on plant growth and processes. There is a lot that people have
just been too lax to research in the past.’ And Geoff Maxwell, director
of the government’s Macaulay Land Use Research Institute, Aberdeen, was
this week plan-ning the first laboratory tests of the likely effect of the
oil on sheep who eat contaminated grass.
By the end of this week, he hopes to have data on how oiled grass and
turnip tops, shipped from Shetland over the weekend, will affect the fermentation
process in the rumen of sheep. Vets are already predicting that flocks will
develop stomach ulcers and die.
‘We also need to know what the long-term effects on soils, vegetation
and sheep will be,’ Maxwell said. ‘Will the hydrocarbons be held in the
soil, for instance? Will the pollution pass into the carcase of the sheep?’
The only practical model, he said, is from the fallout of radionuclides
on hillsides after the Chernobyl accident, ‘where the effects have lasted
much longer than anticipated’.
Ornithologists say that the bird populations most immediately at risk
so far are the long-tailed ducks and a large local colony of shag. But they
warn that the greatest death toll among birds will occur out at sea, far
away from TV cameras, should any of the oil slicks leave Shetland’s shoreline.
Among mammals, the most threatened animals are the otters, because they
rely on their coats to keep them warm. An oil-soaked coat loses its insulating
capacity and the animal will quickly die from hypothermia in the cold waters.
Shetland has the most concentrated and least disturbed otter population
in Europe, says Hans Kruuk of the Institute of Terrestrial Ecology in Banchory.
There are between 700 and 900 animals in all.
‘Luckily, the spill took place where there is the lowest concentration
of the animals anywhere in Shetland,’ he said. ‘The area has only around
1 animal per 10 kilometres of coastline.’ The biggest concentrations are
on the east coast, north of Lerwick. ‘If the slick comes north, it could
do a tremendous amount of damage,’ said Kruuk, after a trip to Shetland.
The Joint Nature Conservation Committee, the government’s main conservation
adviser, this week backed the decision to spray chemical dispersants onto
the oil slick. ‘The priority for nature conservation was to protect the
most long-lived species-and that meant breaking up the slick that was killing
sea birds and mammals,’ said Andy Webb of the JNCC. Bird and mammal populations
could take 20 to 30 years to recover, whereas fish and invertebrates will
recover within five years, he said.
But other marine scientists were less happy. They point out that in
the Netherlands and Norway, which has a similar coastal environment to Shetland,
dispersants are banned because they are too toxic. Webb argues that banning
dispersants suggests a bias towards commercial fishing interests, because
fish can be poisoned by the chemicals, and against nature conservation.
The JNCC advised against spraying near sandy beaches or bird breeding
areas, such as Mousa Sound on the east coast, where sand eels, on which
birds feed, are common. Also, there will be no spraying near fish farms.
Webb conceded: ‘We lack information on the toxicity of the dispersants,
but we have been assured that their toxicity is low.’ Companies have refused
to give conservationists detailed information on the content or toxicity
of the sprays because they insist on maintaining ‘commercial confidentiality’.
Joe Small, deputy director of the Marine Pollution Control Unit, said
that the unit had used three proprietary dispersants: BP’s Enerspersal 1037,
Dasic LTSW and Dispolene 34S, manufactured by the French firm SPPC. ‘We
buy the cheapest available,’ he said. ‘They are all basically the same.
Each manufacturer claims its brand has a secret ingredient and they guard
All dispersants, he said, contain a surfactant which binds the oil to
water and a solvent which spreads it through the water. The UN’s International
Maritime Organization, in its Manual on Oil Pollution, warned in 1988 that
‘some components of dispersants are harmful to humans’ and advises spray
operators to wear protective clothing and for other people in the area,
such as ship crews, to ‘take shelter while spraying is in progress’.
The IMO dismissed reports in the press that it had recommended there
should be no spraying near rocky coastlines. The manual advises only against
washing rocks above the tideline.
‘You have to make a value judgment,’ said Tony Stebbing of the Plymouth
Marine Laboratory. ‘By spraying dispersants, you make the oil miscible throughout
the water column. However toxic or nontoxic the dispersant may be, the effect
of using it is to expose creatures below the sea surface to oil that might
otherwise stay on the surface.’ He said that in this case, where much of
the oil will evaporate quite quickly, dispersants might mix it in the water
column and prevent evaporation. Also, once dispersants are sprayed, protective
booms-placed around fish farms, for instance-are no longer effective at
keeping pollution out. Even so, he backs the spraying because it helps birds
and sea mammals.
For the first time during a major oil spill, defenders of plant communities
have made their voices heard. The charity Plantlife called on the authorities
not to forget Shetland’s plant communities in their clean-up. ‘Plants will
have a vital role to play in the recovery of the environment,’ said its
director, Jane Smart.
She warned that the long-term effects of dispersants on seaweeds, which
took two decades to recover from the Torrey Canyon oil spill off the coast
of Cornwall, are unproven. ‘We say dispersants should not be used, especially
as we have not been told what is in them.’ The fallout of oil onto inland
lochs in Shetland could damage their unusual light- and nutrient-sensitive
Smart joined Scottish Natural Heritage’s earth scientist Alan McKirby
in pleading for the protection of vulnerable sand dunes and beaches. If
heavy mechanical equipment were brought onto valuable dunes in Quendale
Bay, for instance, to remove or treat oil, ‘it could do far more harm to
the delicate vegetation than the oil itself’, said Smart.
McKirby wants a unique neck of sand joining the main island to an islet,
known as St Ninian’s Tombolo, protected from the diggers. The geomorphological
feature is a listed site of special scientific interest. ‘If you remove
half a metre of sand you would breach the tombolo,’ he said.