ExxonMobil can expect a really angry email from PETA real soon. Findings from a scientific review panel have linked the deaths of over 100 melon-headed whales found stranded on the shores of a lagoon in northwest Madagascar in 2008 to a form of sonar being deployed by one of the company's survey vessels.

The International Whaling Commission and Independent Scientific Review Panel (ISRP) had initially concluded that air gun blasts from seismic survey vessels in the area were not to blame, as they in fact took place several days after the incident.
However, a vessel using a different type of surveying technique — a high-power 12 kHz, multi-beam echosounder system (MBES) — was, says the report, “moving in a directed manner down the shelf-break the day before the event, to an area approx. 65 km offshore from the first known stranding location. The ISRP deemed this MBES use to be the most plausible and likely behavioral trigger for the animals initially entering the lagoon system.”
High-frequency sounds like the MBES could have caused the whales to swim into an inhospitable area from which there was no escape. Here's hoping that something gets done about it before more whales meet their demise.