Increasing evidence of Seismic Survey impacts on marine life

An article was published in the BBC News website referring to a recently published paper by Lucia Di Iorio and Christopher Clark[1] indicating that seismic surveys can interfere with Blue Whale feeding behaviors.

The letter mentions that the blue whales produce their short distance feeding vocalizations 2-1/2 times more frequently during the seismic surveys than during non-survey times, and speculate that they may be repeating themselves to make up for signals degraded or masked by the seismic signals.

The seismic signals in question here were generated by “sparkers” which produce a relatively quiet signal from an electrical discharge across electrodes. Sparkers are used for shallow waters and close-to-shore surveys and produce significantly less acoustical energy than the towed airgun arrays.

Increasingly we are finding that seismic surveys have both short and long range impacts on marine life. While it may not seem surprising that a seismic signal that can be heard over 2000 km away from the survey would have biological impacts, until recently there were very few papers examining these impacts and these mostly referred to fish.

Now through recent passive acoustic studies of marine mammals researchers are finding that their results are being skewed by seismic surveys.

It is also not surprising – although a bit disappointing that the Canadian University team who were performing the seismic surveys were not cooperative with Clark and Iorio.

This new information sheds more light on the potential impacts of the ongoing 40+ seismic survey operations that are occurring in the ocean worldwide at any time. Most of these airgun surveys are associated with fossil fuel exploration and extraction.

Fossil fuel just got much more expensive.

[1] Lucia Di Iorio and Christopher W. Clark “Exposure to seismic survey alters blue whale acoustic communication” Biology Letters, September 23, 2009,