Oysters moonlight as pollution sleuths
French researchers hoping to get an early warning on pollution in the ocean have found an unlikely ally in a mollusc more often eaten.
Their findings reveal that, like canaries in a coal mine, oysters near offshore oil platforms can detect minute amounts of hydrocarbons as each one constantly filters hundreds of litres of water a day.
That could alert scientists to tiny infrastructure cracks before they become catastrophic oil spills that threaten wildlife and coastal communities.
Attached to rocks or other supports, oysters are ideal for nearly real-time analysis because “they have nothing to do except notice the surrounding noises and temperature and light variations”, said Jean-Charles Massabuau, a researcher at France’s scientific institute CNRS.
Working with the University of Bordeaux, he has been developing processes for measuring an oyster’s reactions to exposure to oil and natural gas in the water since 2011, alongside biologists, mathematicians and computer specialists.
The bivalve was perfectly made for sampling the quality of the water it filters all day long as it reacted almost instantly to the slightest amount of oil, Massabuau said.
He and his team have built an electrically isolated Heath Robinson aquarium, at the marine research station on the Arcachon Bay, southwest France.
Electrodes are attached to about a dozen oysters in the tank, allowing researchers to measure how quickly each oyster’s valves open and close.
Spikes in valve cycles are the first alert that the mollusc has become stressed. –