Seismic noise altering whale and dolphin activity, oil industry official says

by The Associated Press

Whales and other marine creatures who rely on the silence of their watery world for communication may have more to fear from the offshore oil industry than chemical pollution.

Delegates to an industry conference were told April 30 that noise of air guns used in the seismic search for oil and gas in offshore waters is loud enough to alter whales’ behavior.

Seismic blasts, with an output of from 230 to 238 decibels, are louder than a rock band at 170 decibels and a container ship at 200, said Jack Caldwell of Houston, a vice president at oilfield services firm Core Laboratories.

By contrast, the fin whale’s call is 140 decibels, while pounding surf comes in at 90 decibels.

Caldwell said that, while noise is also known to change behavior of dolphins and other marine mammals, debate remains over whether it is significant or harmful.

At the Offshore Technology Conference, Caldwell issued a call for the industry to contribute about $2 million a year in research funds to augment the approximately $3 million per year the U.S. Navy is spending.

A Gulf of Mexico environmental assessment, delivered to the federal Minerals Management Service office in New Orleans last summer, concluded that the oil and gas industry’s activities offshore were OK with the exception of seismic work. That, Caldwell said, was deemed adverse — but not significantly so.

Caldwell said a dozen types of whales and eight types of dolphins can be found in the Gulf of Mexico. A group of sperm whales has been spotted numerous times in the vicinity of oil platforms off the Mississippi delta, he told the Houston Chronicle for May 1 editions.

Whales have limited security, including some provisions in the Marine Mammals Protection Act that require a permit for harassment. Also, voluntary and mandatory mitigation to protect whales includes staying out of migration paths and breeding areas when the creatures are present.

The offshore industry could also monitor for whales’ presence, either from ships or from aircraft, and establish safety zones to shut down operations if they get too close.

Additionally, a “soft start” to the seismic noise could make whales leave the vicinity before the loud noises start.