Ocean noise cited in '08 whale mass stranding off the coast of Madagascar

The author examins a dead melon-headed whale in Madagascar.Four years ago I rushed to Madagascar to help stop over 100 melon-headed whales from stranding and dying along the islands’ shores. Like most cetacean species, melon-headed whales are very social animals. They rely on sound for communication and echolocation that are essential to reproduction, feeding and navigation. This is a difficult prospect in an ocean environment that is getting louder and louder due to human produced sounds.  

This week, an Independent Stranding Review Panel (ISRP) released their scientific findings regarding that mass stranding that took place in 2008. After reviewing the stranding data and information about activities taking place in the vicinity, the panel concluded that the use of multi-beam echosounder systems (MBES) was “the most plausible and likely behavioral trigger for the animals initially entering the lagoon system”, leading to an inability to return to the open ocean and subsequent stranding.

This finding is incredibly significant, as this is the first known stranding event closely associated with relatively high-frequency mapping sonar systems.

I responded to that stranding event with CT Harry, another member of the International Fund for Animal Welfare’s (IFAW) Marine Mammal Rescue and Research (MMRR) team, and colleagues from the Wildlife Conservation Society (WCS). IFAW MMRR was asked to participate because of our vast experience with mass stranding response and particularly our innovative mass stranding prevention program.

So back in June of ’08, and within 24 hours of notification, we were in the air with loads of gear headed for Antsohihy in Northwest Madagascar. Many of the animals had already died before the event had made global news, but we hoped we could make a difference for those that remained out of their normal habitat, seemingly trapped in the lagoon system. 

Our efforts met with mixed success. 

We used boats to try to herd the animals from the Port of Antsohihy, to the open water of the ocean - a distance of over 69km. We had never attempted to herd animals such a long distance, over such a wide area (almost 7.4 km at its widest). Although we moved many of the animals closer to the entrance of the lagoon each day, only a few animals made it out of the lagoon during our efforts.

We left much of our equipment behind so local responders could continue their efforts to save the animals.

The impact of sonar, seismic and other noisy industrial activities on marine mammals extends well beyond Madagascar. Ocean noise pollution is a growing problem, and a global one, filling the underwater world with a cacophony of sounds from explosives, pile-driving, drilling, dredging, seismic blasts and ship noise.

IFAW is working around the world to address these threats and improve approaches to offshore oil, gas and industrial development and shipping. From the feeding grounds of endangered Western Gray Whales near Sakhalin Island in the Russian Far East, to critical whale habitat areas around Australia, to the Atlantic coasts of the United States and Europe, IFAW is working to promote practical solutions that reduce the deadly threat of ocean noise pollution  and protect our planet’s whale populations. 

This short video narrated by IFAW global whale spokesperson Pierce Brosnan highlights the urgency of the problem and this important work.

Every stranding event is different and must be investigated thoroughly and objectively to help us understand the possible causes.  What we do know is that ocean noise is a real and growing threat to dolphins and whales worldwide…one that we cannot afford to ignore.

--KM

For more information on the work of our Marine Mammal Rescue and Research team, visit our team page.

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