The US Bureau of Ocean Energy Management, Regulation, and Enforcement last month asked the National Marine Fisheries Service for yet another study to see if airguns used in underwater seismic surveys could damage the hearing or otherwise harm or harass whales and dolphins in the Gulf of Mexico. One would think seismic surveys have diminished with BOEMRE still sitting like a mother hen on a pile of drilling permits for the gulf.
As a result, in a recent survey by the Fraser Institute, the US portion of the gulf plummeted from 11th place in 2010 to the 60th spot in a list of the best places in the world for oil and gas investment. It marked one of the biggest drops in the rankings this year, since last year's survey was before the Macondo blowout and tighter federal restrictions on drilling in the gulf. Another investigation of "whale harassment" could delay the gulf's recovery even longer.
Back in 2002, BOEMRE's predecessor, the US Minerals Management Service, set an "exclusion zone for whales" at and below the sea surface surrounding the center of a seismic airgun array and within the immediate vicinity of the survey vessel. The same regulation required crews to ramp up initial firing of airguns, starting with a single unit of the lowest power and increasing at a rate of 6 db every 5 min until the entire array is operating at desired intensity. The idea is to "push" out of the area any marine animals sensitive to underwater noise. Seismic crews were willing to do so, since no one wants a whale thrashing around in geophone streamers strung out 8 km behind a seismic vessel.
That same year, MMS started a 3-year study to determine if seismic surveys had any effect on endangered sperm whales in the gulf. That study utilized an industry-provided seismic vessel. The Office of Naval Research, Texas A&M Research Foundation, and the International Association of Geophysical Contractors participated in that research. Such effects also have been studied off California and in other water bodies around the world.
Meanwhile, a research program at Cornell University using 30 years of military data showed noises made by whales travel up to 3,000 km, far further than sounds of seismic airguns. Moreover, humpback whales produce a wide array of sounds, including the highest and lowest frequencies humans can hear. So why has no one ever studied whether the wide range of frequencies and extended carry of sounds by whales and dolphins are endangering the hearing of humans swimming off beaches around the globe? Considering their wide range and additional reach, it would seem some whales would do more to disrupt seismic surveys and sensitive marine animals than the other way around.
One has to wonder, too, why careful development of offshore oil and gas is so often investigated for harming sea life, while no one questions the use of power boats to take tourists and environmentalists among pods of whales or dolphins. Maybe it's because movies and television has everyone wanting to take a swim with Orca or Flipper.
Back about 1960, I spent my high school summer vacation loading shot-holes with fertilizer and dynamite on a seismic crew out in West Texas. Never did hear how loud a pop it made when they set off those explosives, because by then I was busy loading the next pattern of holes. I'm sure there must have been considerable sound when they touched off a few dozen at the same time, since the primary purpose was to bounce sound waves off underground formations and back to geophones near the surface.
Yet I've never heard of a government official calling for a study to determine if those blasts were detrimental to the hearing or mating habits of the jack-rabbits, armadillos, or rattlesnakes in the surrounding desert. Guess a gaunt West Texas jack-rabbit infested with screw worms or a cold-eyed poisonous snake rattling its warning just can't compete with sea mammals for cuteness.