Fact Box: Whales, Dolphins and Seismic
  • Concerns are often raised by environmentalists about the impact of offshore seismic surveys on whales and dolphins.
  • However, according to John Hughes, an expert in this area, there is no evidence from over four decades of seismic surveys that whales and dolphins are adversely affected by seismic sounds.
  • This is not surprising given that the sounds they emit themselves, such as their vocalisations and activities like breaching, are very similar to the seismic sounds they would experience quite close to the acoustic array.
  • Of course, they generally do not get close enough to the vessel or the seismic array to experience something similar to their own sounds, because of the risk of collision.
  • In that context, it is interesting to note that significant numbers of whales and dolphins perish annually as a result of vessel collisions. (These are generally as a result of fast moving ships that have no warning signals, unlike seismic vessels which move very slowly, 4-5knots and actually have a warning signal, the seismic source itself.)
  • Worse still, it is estimated that between 300,000 and 600,000 marine mammals die annually around the world as a result of entanglements in fishing gear, shark nets, etc. This is called by-catch – a euphemism for slaughter.
  • It is astonishing that there is such concern voiced about seismic surveys and marine life, contrary to the evidence, when there seems to be almost total silence regarding the estimated 1000+ deaths/day occurring as a result of other causes and none from seismic.