Oil and Gas Surveys Harm Shellfish, Too


Marine mammals, fish, crustaceans, octopus and squid.  The list of marine species threatened by intense noise pollution continues to expand, not surprisingly given the vital importance of sound to the ocean environment.  Now shellfish are the latest taxa to join this unfortunate club.

In a study published today, an international group of researchers found that noise from seismic airguns—a technology widely used by industry to troll for offshore oil and gas—produces disturbing malformations in scallop larvae, with abnormal growth and bulging in the soft body of the animal.  The evidence was clear-cut: none of these defects occurred in larvae kept in quiet tanks, unexposed to the airguns’ booming sound, but exposed larvae suffered in large numbers.  And the implications for both shellfish and shellfish fisheries are concerning, since both the defects and developmental delays that the study documented are likely to reduce survival.

The study tested sound levels that can extend hundreds of meters from large-volume airguns, posing a risk to colonies near lease blocks where survey lines are concentrated.  But, as the researchers note, damage could potentially occur at greater distances given the ways sound concentrates in the ocean and the potential for harm at much lower noise levels than the study examined.  Indeed, we do not know the point at which the widespread developmental disorders seen in the study begin to occur. 

For years fishermen around the world—Australia, Canada, and Norway, for example—have complained about loss of catch during and after airgun surveys.  Today’s research ought to give us yet more pause about opening up most of the eastern seaboard to seismic, as the administration, to palliate the drill-everywhere crowd, has unwisely proposed.  And it only underscores the need to address more generally the mounting, chronic problem of noise in the sea.