Sound is as important to whales as vision is to us. Sound travels farther in the ocean than light does — so whales and dolphins grunt, call, click or sing, or listen intently, and their lives depend on sending and receiving these acoustic cues reliably. They’re quite good at it. Whales and their prey have evolved these acoustic systems over millennia. The problem is that in the last hundred years or so, we have started competing with whales for acoustic space by using ships and conducting other activities that create a lot of underwater noise (mostly unintentionally). So a whale singing in a noisy habitat is like having a great cell phone that relies on a terrible network provider. Unfortunately for whales, fish, squid and other marine life, the consequences of a “dropped call” are more serious than they are for us. If human activities jam whale acoustic signals, the information lost is not trivial. We suspect that the acoustic information being transmitted is of the kind: “There is a predator just around the corner.” Or, “Eat this fish. It may be the last one you see for days.” Or, “Mate with me.” You don’t want to miss these calls.
We recently published a paper reporting ocean noise levels in important whale habitats along the BC coast. At the same time, we released an animation that outlined the key concepts. Our research showed that the most important habitats for killer whales were the noisiest; important habitats for humpback whales were comparatively quiet.
We thought you might like to hear for yourself what those sites sound like. Don’t worry. We won’t make you listen to all 10,000 hours of recordings, but our co-authors (Dimitri Ponirakis and Chris Clark) at Cornell University’s Bioacoustics Research Program distilled some of the results into this nifty PowerPoint slide. It’s a big file (22MB), but it lets you see and hear what Haro Strait and Douglas Channel sound like.
The neatest part of Dimitri’s work is that there was a windstorm partway through this period. You can hear the wind on the recordings made off Kitimat (Douglas Channel), but the same wind noise cannot be heard in Haro Strait over the background noise from ships. We still have a lot of work to do to understand what these noise levels might mean to whales and fish in terms of ecological effects, but we thought you might like to see and hear some of the recordings. Please let us know what you think.
<iframe src=”http://www.slideshare.net/slideshow/embed_code/28172039″ width=”427″ height=”356″ frameborder=”0″ marginwidth=”0″ marginheight=”0″ scrolling=”no” style=”border:1px solid #CCC;border-width:1px 1px 0;margin-bottom:5px” allowfullscreen> </iframe> <div style=”margin-bottom:5px”> <strong> <a href=”https://www.slideshare.net/oceansinitiative/fig-s1-exampleltsasandaudiofilesharostraitandkitimat” title=”Fig s1 example_lts_as_and_audio_files_haro_strait_and_kitimat” target=”_blank”>Fig s1 example_lts_as_and_audio_files_haro_strait_and_kitimat</a> </strong> from <strong><a href=”http://www.slideshare.net/oceansinitiative” target=”_blank”>Oceans Initiative</a></strong> </div>