Industry noise probe into whales

The Northern Gulf of Mexico has an increased oil exploration activity that is progressing into the deeper water inhabited by a population of sperm whales

Fife scientists are investigating if noise generated by the oil and gas industry might affect the day-to-day behaviour of sperm whales.

Dr Patrick Miller, of St Andrews University, has been finding out how increasing sound affects sperm whales.

He has looked at how the loud noise of airguns used to search for oil and gas reserves might affect their behaviour.

He focused on foraging behaviour, which occupies 75% of the time of sperm whales in the Gulf of Mexico.

Dr Miller, lecturer at St Andrews University's School of Biology and a senior researcher in the School of Biology's Sea Mammal Research Unit, was the lead author on the study.

The study was not entirely conclusive because behaviour is naturally highly variable, but it helps to begin to predict how animal welfare may be affected Dr Patrick Miller St Andrews University

He said: "It is important to investigate the extent to which sperm whales might be disturbed by underwater noise so that appropriate precautionary measures can be put in place if needed."

The Northern Gulf of Mexico has become a location with increased oil exploration activity that is progressing into the deeper water inhabited by a population of sperm whales.

Dr Miller said: "The study was not entirely conclusive because behaviour is naturally highly variable, but it helps to begin to predict how animal welfare may be affected.

"We were able to develop an experimental method that allows us to test specific hypotheses of how sperm whales might react to airguns and found some interesting results."

Gradual noise

Sound and movement recording tags were attached to eight sperm whales using suction cups, and their behaviour was recorded before, during, and after the whales were exposed to the underwater noise.

The study tested the hypotheses that sperm whales would respond to the noise by moving away from it, altering their behaviour patterns, swimming harder to move away from the sound or to catch prey, and perhapsr catching fewer prey per dive.

Dr Miller said: "Interestingly, the sperm whales observed did not avoid the airguns, continuing on their previous course of travel.

"Most animals continued with deep-dive foraging throughout the exposure, though one resting sperm whale seemed to delay deep diving while it was near the airguns, possibly to avoid the high levels focused directly underneath an airgun array."

A gradual increase in the sound level gives animals a chance to move away before they are exposed to the full level of the array.

The research was part of the Sperm Whale Seismic Study (SWSS), a five-year co-operative study on the lives of Gulf of Mexico sperm whales and how seismic vessels might affect them.