Virtual marine biology camp

by oceansadminEducation, Exploration, WhalesPosted on 38 Comments

During the school shutdowns, we’ve decided to launch a (very) informal, impromptu, virtual marine biology camp. Follow us on Facebook or Instagram, and you should see us in your news feed when we go live, Mondays and Thursdays at 11 am Pacific time. For Paddington Bear fans, you’ll note that this is conveniently timed to coincide with elevenses. We’ve been using this as an excuse to bake yummy treats, for educational purposes of course. The recipes help us practice our reading and math skills. What are you making for Monday’s elevenses?

Thanks, GeekWire, for the great profile of this event. We did this primarily as parents of an almost six-year-old kid who is really missing her friends. Please like, comment, share, and tell us in the comments below what you’d like to see us cover in future episodes. We’ll keep this up as a free community service as long as schools are closed, kids are interested, and our nonprofit team has the capacity to keep up with demand.

Underwater noise from airplanes: An overlooked source of ocean noise

by oceansadminAcoustics, Exploration, Ocean Noise, Women in SciencePosted on No Comments

We tend to think of the air-water interface as a barrier to noise. Planes fly over the ocean all the time, but conventional wisdom tells us that most of the sound bounces off the surface of the ocean, and has little impact on the whales and dolphins that swim beneath the surface. A classic paper from 1972 tells us we only need to worry about airplane noise in a narrow cone under the flight path.

We recently worked with colleagues from Curtin University, Udayana University, and Conservation International Indonesia to measure noise levels from commercial jets taking off from coastal runways in Bali and Australia. We found that under certain conditions, those jets introduce up to 130 dB of noise into shallow waters. Those noise levels are high enough to cause disturbance to killer whales.

Planes fly pretty quickly of course, so any noise exposure is fleeting. But during the busiest periods, we recorded planes taking off every 3 minutes! Below is a map of runways, with coastal runways (<10 m above sea level) in red.

We conducted this study during Nyepi, the Balinese Day of Silence. We did not expect to be able to hear airplane noise over background conditions, but we got lucky. Did you know that fish have a chorus of song, just like the dawn chorus of songbirds? Check out the sounds of fish singing below:

And this is the sound of a small boat passing by our hydrophone. In the last few seconds, you can hear the roar of a jet aircraft taking off from the nearby runway of Denpasar airport, Bali, Indonesia.

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Runways of the world, with coastal (<10m above sea level) marked in red

 

Our Vision for Recovering Killer Whales: A Clean, Quiet Ocean Full of Salmon

by oceansadminAcoustics, Conservation, Exploration, Habitat, Human Impacts, Killer Whale Conservation, Ocean Noise, Protecting Species, Sustainable Fisheries, Wildlife Health, Women in SciencePosted on No Comments
Southern resident killer whales in Haro Strait. Photo by Toby Hall
Southern resident killer whales in Haro Strait. Photo by Toby Hall

Southern resident killer whales are in decline.  Our recent population viability analysis on southern resident killer whales predicted that, if threats remained constant, it should take several decades for the population to decline from 80 to 75 whales. In fact, that decline took only three years. We fear that the decline is accelerating, and we may be reaching a tipping point.

By studying killer whales from land, we can measure their responses to noise without adding the noise of a research boat to the equation. We use noninvasive techniques to measure swimming speeds, breathing rates, and other behavior. Our work on both northern and southern resident orca has shown us that the whales spend 18-25% less time feeding in the presence of boats than in their absence.

We recently joined an international, interdisciplinary study to understand the relative importance of the three main threats to recovery in the endangered killer whale population. The whales are facing a perfect storm of threats–not enough salmon, too much noise, and too many toxic chemicals in their bodies–but lack of prey is at the eye of the storm. This research shows it will take 30% more big, fatty, Chinook salmon than we’ve seen on average over the last 40 years for the population to reach our recovery goals. That will take time, but we have to start now. Meanwhile, reducing noise and disturbance can help make it a little bit easier for whales to find the salmon we have now. In the coming months, we will be revisiting our study on identifying critical foraging areas in the Salish Sea and strengthening their protection.