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Tuesday, 23 January, 2001, 11:29 GMT
Q&A: Galapagos clean-up
Paul Kingston, an oil spillage expert from the Centre for Marine Diversity and Biotechnology at Heriot-Watt University, answers questions about how to minimise the damage.
Is it true that cleaning up can do more damage to the environment than the oil?
In general, where there is heavy oiling of a shore, there can be no doubt that removal of the oil and cleaning of the shore will speed up recovery.
This applies to rocky shores and most kinds of sandy shores. However, there are some types of shore, for example saltmarshes and mangrove swamps, where cleaning can do more harm than good and in these cases the best policy is to leave the oil to degrade naturally.
What is the most effective way to clean up?
The effectiveness of a particular cleaning method will depend on the size, nature and location of the spill.
There is also some difference of opinion as to which method is the most effective and the least threat to the environment.
Spills of less than 5,000 tonnes that occur offshore and in deep water are probably best dispersed. It is usually impractical to disperse larger spills, although dispersants may be used locally where the oil is heading for an environmentally sensitive area - say a large bird or seal colony.
Whenever dispersants are used, there must be a suitable receiving environment, such as water deeper than 20 metres and reasonable water exchange. Dispersal is the preferred method in the UK.
Containment is the preferred method in some countries (eg Norway) and is usually used in conjunction with some sort of skimmer, suction device or adsorbent system.
The use of floating booms to contain the oil is very dependent on the weather. Most cannot be used in waves of more than one metre in height or in currents greater than one knot.
Booms can often be used very effectively to deflect an approaching slick onto a sacrificial beach (usually a sandy shore) where the oil can be mechanically scooped up.
Are there enough people with the right expertise in the Galapagos?
The Galapagos oil spill is quite small. Most reports put the quantity at about 150,000 gallons - that is less than 90 tonnes. To put things in perspective, the Braer oil spill in the Shetland Islands in 1993 was 85,000 tonnes.
However, the impact of an oil spill cannot be related to its size but is dependent on where and when it takes place. The shores of the Galapagos support a wide range of species that are unique.
For example there are only 400 pairs of breeding lava gull in the world, all living on the Galapagos. We have no idea how the unique marine iguanas will respond to diesel oil which contains particularly high levels of toxic hydrocarbons.
The Ecuadorians have called in expertise from the US to help them to contain and clean up the spill, and the recently appointed head of the Marine Group at the Charles Darwin Research Centre has come from Tasmania where he dealt with the Iron Barron oil spill five years ago.
I and my colleagues, who have many links with the Galapagos, have already offered our services should they be needed.
When you were in the Galapagos did you think they were at all prepared for such an accident?
I gave a lecture on the effect of oil spills on the marine environment at the Charles Darwin Research Station in 1999. Amongst the scientists, there were naval people from the port authority.
The problem there is that although there was some awareness of the possibility of a spill accident there were no resources to set up an effective response capability.
How long do you think it will take for wildlife populations to recover?
Most marine animal populations are remarkably resilient, particularly those that live on exposed rocky shores. This is because the natural conditions for existence are very harsh and major natural 'wipe outs' are not uncommon.
However, recovery of an ecosystem is difficult to estimate. This is because ecosystems are dynamic, and change markedly from year to year.
In general most ecosystems appear to recover after an oil spill within two to five years. This is because in most parts of the world there is a vast repository of individuals to replace those that have been killed.
In the Galapagos, this may not necessarily be true, as some species are unique to the islands and it is quite possible to kill them all at a single stroke.
How much damage is done in the Galapagos islands from minor spillages which go unreported?
It is a sad fact that you can find flotsam and jetsam washed up a many of the shores around the islands. There is no question that there is chronic input of oil into the sea around the centres of population.
Indeed even before the spill, we had been intending to initiate a study to look at the impact of the huge number of boats that are to be found in the bay at Puerto Ayora on the island of Santa Cruz .
How can you supply places like the Galapagos with oil without risk ?
The population of the Galapagos islands is burgeoning. The Ecuadorian Government is struggling to contain it.
The quality of life on the Galapagos is so much better than on the mainland that people have been flocking there for some years. Mercifully, the government has curtailed this immigration, but the problem will not go away.
More than half the people on the islands are under the age of 16, so the future, in terms of its pristine state, is grim. The population will require oil, and there is no other practical way of bringing it to the islands.
There will be a risk of a re-occurrence of an oil spill well into the future.
23 Jan 01 | Americas
Galapagos wildlife emergency
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