14 DAY TRIAL // Experiments carried out by scientists led by Professor Guy Claireaux at the University of Brest in France suggest that the practice of using various chemical dispersants to clean up accidental oil spills at sea can often do more harm than good.
The specialists maintain that, as far as they can tell, the use of chemical dispersants to treat oil spills can only benefit animals at the water's surface.
The ones living underwater are likely to be negatively affected by the cocktail of harmful chemical compounds that works its way into their natural habitats.
In order to investigate the impact that chemical dispersants have on aquatic animals, the researchers have carried out a series of experiments on an oceanic fish species commonly known as the European sea bass. Science Daily explains that, during these experiments, fish belonging to this species were made to spend a total of 48 hours in water contaminated with untreated oil, chemically dispersed oil and dispersant alone.
The fish were then monitored for 6 weeks.
During this second stage of the experiments, the scientists tried to determine how their exposure to the aforementioned environments had affected the fish's behavior and development.
It appears that both the fish exposed to untreated oil and the ones that got to swim around in chemically dispersed oil had trouble coping with slightly elevated temperatures and reduced oxygen availability.
What's more, they found it difficult to swim against a current.
The specialists say that, oddly enough, the fish belonging to the first category were in better health than the others.
This suggests that chemically dispersed oil harms underwater marine wildlife more than untreated oil does.
The fish exposed to chemical dispersants alone performed surprisingly well on the tests they were subjected to. In fact, they did not show any signs of having been affected by the presence of chemical dispersants in their swimming tanks.
“An oil slick reaching the shore is not good for tourism and organisms living on the coast line. Treating the slick at sea will avoid or reduce these problems affecting surface animals (birds and marine mammals).”
“On the other hand, oil dispersion will increase the contamination of the water column and the organisms that occupy it,” Professor Guy Claireaux stressed.