An international group of scientists and animal experts have published a set of guidelines to minimize the effects of underwater seismic impacts on whales and other vulnerable marine species made by the oil and gas industries.
Researchers from the International Union for the Conservation of Nature's Western Gray Whale Advisory Panel (WGWAP) and Sakhalin Energy Investment Company Ltd., collaborated on the project, calling the step-by-step set of guidelines the "most thorough, robust and practical approach to minimizing and monitoring the risk of harm to vulnerable marine species" made by underwater seismic activity, which is primarily made on the seafloor during oil and natural gas exploitation attempts.
Their study is published in the journal Aquatic Mammals.
"This is a valuable tool for oil and gas companies, regulators and others on all aspects of developing and implementing successful environmental monitoring and mitigation programs that are precautionary, responsible and effective," said lead author Doug Nowacek, a WGWAP member from Duke University.
"We hope our guidelines on how to reduce the environmental impacts of seismic work in the oceans will find their way into the manuals of energy companies and environmental agencies around the world," he said.
At the heart of the issue is the system of seismic surveys used by the oil and gas industries, which use powerful airguns to blast sound waves to the ocean floor. The echo data created by these airgun blasts allows detailed maps of the seabed to be rendered, providing oil and natural gas companies with information on the best places to drill for resources.
But because whales and other marine creatures rely on sound for navigation and communication, the airgun blasts can be disruptive and harmful to their way of life, causing behavioral changes than can affect foraging and nursing, or result in direct physical damage, the researchers said.
For their research, the team focused on whales around Sakhalin - a region on the Russian coast, just north of Japan with huge offshore oil and gas deposits. The area is also a vital feeding ground for gray whales.
"Key to minimizing impacts during seismic surveys is advance knowledge of marine life distribution and migrations and timing a survey accordingly," said study co-author Greg Donovan, chairman of the WGWAP Seismic Survey and Noise Task Forces and Head of Science at the International Whaling Commission. "In the Sakhalin case that means conducting the survey as early as possible in spring when the ice has melted but most of the whales have not yet arrived."
While the researchers stress that a unique plan of action must be taken to minimize harm to marine life in each area of resource exploration, they say this can be done under a set of unified guidelines.
These guidelines include obtaining baseline ecological data, conducting detailed advance planning and critical review of survey design and mitigation approaches, restricting the survey area and limiting estimated noise levels to minimize the "acoustic footprint" left by the survey.
Other recommended guidelines include employing real-time visual and acoustic monitoring of noise levels, whale locations and behavior before, during and after the survey, and halting the survey if whales get too close or show strong reactions to seismic activity.
"Our paper draws upon the experience and practical knowledge of the industry as well as rigorous applied science from acousticians and marine mammal scientists to develop a broadly applicable framework for minimizing the potential impacts of seismic surveys and quantitatively assessing the efficacy of mitigation measures used," Donovan said. "Our goal was to synthesize Sakhalin lessons learnt and develop an approach to enable seismic surveys to be conducted in an environmentally responsible manner, regardless of purpose or species within the region."
Dr. Randall Reeves, chairman of WGWAP and Cetacean Specialist Group of IUCN Species Survival Commission, added:
"If we are serious about conservation, we cannot afford to remain aloof and stand apart from discussions with industry. In the case of offshore oil and gas, the risks to nature are huge, and credible science must be brought to bear for both measuring and minimizing these risks."