As oil billowed out of the floor of the Gulf of Mexico in the summer of 2010, much of the soupy black liquid was immediately treated with soap-like dispersants. This emergency action broke the oil down into tiny microdroplets—preventing millions of gallons from forming blobs that can coat bird feathers and overwhelm larger wildlife.
While these dispersants help ward off certain kinds of damage, they also create questions of the long-term effects to the Gulf's suspension feeders: smaller marine life that eat by filtering water.
“Microdroplets could pose problems for smaller suspension-feeding animals if the oil droplets are consumed and are toxic,” said Chris Langdon, an OSU fisheries professor who is studying the biological effects of oil on the development of Gulf bivalves, like oysters, clams, and mussels.
In bioassay experiments, OSU scientists exposed oyster larvae to water that has been mixed with oil to determine its toxicity. After a few days, they observe how many eggs hatch and if the larvae are normal or deformed. Early tests have shown that weathered and non-weathered Gulf oil is not particularly toxic to oyster larvae, but tests will continue.
Further study is needed to qualify the harmful effects of dispersants on oyster larvae. About 2 million gallons of dispersant were or sprayed on surface waters or inserted into oil gushing near the underwater wellhead of the Gulf oil spill.
OSU’s Hatfield Marine Center is hosting research that's vital to the restoration of the Gulf of Mexico because of its unique and modern facilities. OSU scientists are able to draw on the celebrated Molluscan Broodstock Program for oyster seed, as well as the site's large-scale production of algae that's necessary to raise larvae for research.