Washington, August 22 : A five-year study has shown that noise pollution - especially noise generated by seismic air guns during geophysical exploration for oil and gas - seems to have minimal effect on endangered sperm whales in the Gulf of Mexico.
The multi-year 9 million dollars study was conducted by the Minerals Management Service and featured cooperation with the Office of Naval Research, the National Science Foundation and the National Fish and Wildlife Foundation, with researchers from Texas A and M University leading the way.
Though not often seen, sperm whales are regular visitors to and residents in the Gulf of Mexico.
They are the largest of all toothed whales and can reach lengths of 60 feet or more and live 60 years or longer. Their primary diet is squid and fish and they have been known to dive as deep as 7,000 feet.
Sperm whales are not often seen because they prefer to stay in the deep waters of the Gulf, usually in depths of 3,000 feet or more and at least 150 miles offshore, according to professor Doug Biggs from Texas A and M University.
"Sperm whales go to where their food source is, and that means very deep water. So folks that do see them are marine mammal observers who ride the seismic survey vessels and the workers on the big oil and gas rigs, and even that does not happen often," said Biggs.
According to Biggs, over the course of five summers, 98 sperm whales were tagged with devices that relayed back critical data such as measurements about sound levels and behavioral aspects of whales, including tracking their movements.
Of particular concern was the effect that loud low-frequency noises, such as those created by seismic activity, might have on sperm whales in the area.
Oil and gas companies prospect for subsea reservoirs by firing air guns during their seismic work, which government regulators thought might negatively affect sperm whale behavior.
But, the study found no unusual effects of controlled exposure to seismic exploration on the swimming and diving behavior by sperm whales in the Gulf, and also revealed a wealth of data about sperm whale biology and habitat.
"The bottom line is that air gun noise from seismic surveys that are thousands of yards distant does not drive away sperm whales living in the Gulf," said Biggs.