Sonar mapping is believed to have triggered the stranding of about 100 melon-headed whales in Madagascar.

The 2008 stranding was traced back to a "multi-beam echosounder system operated by a survey vessel contracted by ExxonMobil Exploration and Production (Northern Madagascar) Limited," a Wildlife Conservation Society press release reported.

This is the first report that links a mass stranding with this type of sonar. The results are concerning because sonar is widely used, being employed by the hydrocarbon industry, military, and research ships.

 "The potential for behavioral responses and indirect injury or mortality from the use of similar MBES [multi-beam echosounder systems] should be considered in future environmental assessments, operational planning and regulatory decisions," the report stated.

The Wildlife Conservation Society (WCS) and the International Fund for Animal Welfare (IFAW) supported the findings of the study.

"WCS and IFAW support these conclusions that add to a mounting body of evidence of the potential impacts of anthropogenic noise on marine mammals," Dr. Howard Rosenbaum, Director of the Ocean Giants Program for WCS, said. "Implications go well beyond the hydrocarbon industry, as these sonar systems are widely used aboard military and research vessels for generating more precise bathymetry (underwater mapping). We now hope that these results will be used by industry, regulatory authorities, and others to minimize risks and to better protect marine life, especially marine mammal species that are particularly sensitive to increasing ocean noise from human activities. "

Researchers hope to discover what causes the stranding of whales and other marine life in order to prevent similar events from happening in the future.

"Mass stranding response is challenging under the best of circumstances. Together with local individuals and the government of Madagascar, we provided the expertise to rescue as many animals as possible and medical care to those that stranded alive," Katie Moore, Director of Animal Rescue at IFAW, said. "Equally important was to gather as much data as possible from the animals to address the root cause of the stranding. We are pleased to see the ISRP report and its conclusions, which will hopefully be used in shaping future conservation policies."