Written on December 18, 2012 at 11:18 am, by cstephens
NOAA has turned ocean noise into something you can see. In a revolutionary new project, the agency documents both noise pollution in the world’s ocean, and the location of whales that suffer the most from human-caused noise pollution in the sea.
The new maps will constitute the world’s largest sound map. NOAA used bright colors to show the distribution of noise pollution, with some ocean noises so loud the sound waves are shown on the map as traveling for hundreds of miles through the ocean.
The project doesn’t just seek to map ocean noise, it also aims to draw attention to the growing problem of underwater noise pollution and its deleterious effects on whales. Human-caused ocean noise—from seismic air gun blasts as oil companies explore for oil and gas to the constant moan of ship propellers to construction equipment drilling in the seafloor— can cause permanent damage to whales’ hearing. They depend on their sensitive hearing to navigate, find food, and locate other whales, including mates and their young.
The project began in 2010 at NOAA Administrator Jane Lubchenco’s request.
Learn more by reading the New York Times article here.
Written on November 6, 2012 at 2:59 pm, by cstephens
A major victory was recently won for both humans and animals living in the far north of Canada, near Greenland. For the indigenous humans living in five Inuit villages, a court order blocked a German icebreaker from conducting seismic tests in the area, reaffirming the Inuits’ autonomy over their environment. The court order might have been an even bigger victory for the marine mammals living nearby, now that they will no longer be subjected to deafening auditory blasts. These marine mammals, such as bowhead whales, beluga whales, and narwhals, use sound, or echolocation, to navigate, find food, locate mates, and simply live, and underwater noise pollution can cause confusion and even death.
Although the Canadian government said that the seismic testing was simply for the purpose of “mapping undersea geology,” it was clear to the villagers, and others, that the seismic testing was about discovering oil and gas. Seismic exploration goes hand-in-hand with oil and gas development. And both can cause irreparable harm to the humans and animals that live nearby. As the Arctic sea ice melts, more and more of the Arctic is opening up to this kind of exploration, and both humans and animals may suffer from it.
A recent paper was published by marine research firm JASCO on localizing walruses using a single hydrophone. The technique they have refined is detailed in the article and involves assessing “multipath signals” – echoes from the sea surface and seafloor – along with the direct signal to track the movements of walruses in the Arctic. This is remarkable because locating a sound source usually involves two or more receivers.
For example, all terrestrial vertebrates have two ears which allow us to locate sound sources. We do this using a number of different cues. One of the obvious cues is amplitude: if the sound is louder in one ear over the other we assume that the sound source is closer to the louder ear. Another more subtle cue is ‘time of arrival’ which allows us to locate a sound source by the difference between the times it takes for the sound to arrive at one ear and the other.
These two cues serve to give us a general bead on the horizontal source of a sound – whether it is to the left or right, in front of us or somewhere in between. This method is adequate for birds, frogs, and lizards in the context of their survival needs.
But we mammals have more complex localizing needs from sound so we have developed outer ears that provide us with more subtle cues – allowing us to determine things such as how close or far, and the height or azimuth of a sound.
Mammals with movable ears such as cats and horses can use their outer ears like periscopes to hone in on a source of sound. Primates such as us humans have fixed ears, so we derive location cues from secondary reflections off the pinnae of our ear.
It happens that all the whorls on our outer ears collect and reflect sound into our ear canal with a tiny time delay after the primary sound hits our ear drums. This is a bit like the “multipath” cues that JASCO teased out in their work (but with much less math).
These three cues – amplitude, time of arrival, and delay of the secondary reflection allows us to pinpoint the source of a sound with uncanny accuracy.
Of course marine mammals (with the exception of sea lions, polar bears, and otters) do not have outer ears. We know that they have equal, or even more complex localizing needs from sound, especially the Arctic animals that spend a good amount of time in the deep and dark waters of the Arctic winter.
It has been less than 100 years that humans have started to use sonar in marine environments. The folks at JASCO are rolling back sonar frontiers, showing us that complex data can be derived from single receivers.
Marine mammals such as whales and seals have been adapting to their acoustic environment for 20-30 million years. It stands to reason that these animals have evolved some pretty complex adaptations to sound perception.
Hopefully we can come to understand and learn from some of these adaptations before we cloud out their arctic environment with sounds to which they have not adapted.
Written on February 1, 2012 at 10:50 am, by mstocker
573 scientists signed a letter calling on the Obama Administration not authorize drilling in the Arctic until we have a better understanding of the habitat and biota that oil and gas operations will be disrupting, and to “respect the national significance of the environment and cultures of U.S. Arctic waters and demonstrate the value that [the] Administration places on having a sound scientific basis for managing industrial development of the Outer Continental Shelf.”
This is consistent with calls from Alaska Natives, fishermen, hunters, citizens, conservation groups, and just about everyone except the Oil Industry to NOT drill in the Arctic.
Two of the world’s most authoritative voices on ocean acoustics are sounding off about the impacts of human-generated noise on marine creatures. A recent opinion piece posted on CNN.com by Chris Clark and Brandon Southall make a compelling case that the U.S. should:
Fully assess and comprehend the acoustic footprint of our offshore and coastal activities;
Encourage and accelerate the development of noise-reduction technologies; and
Change federal regulation on ocean noise toward a more holistic and biologically relevant risk assessment system
These recommendations are right on target, especially as the National Marine Fisheries Service works to establish new regulations for offshore oil and gas development in the Arctic [link to act page] and the Federal Government rushes to lease and develop millions of acres of America’s outer continental shelf for energy development. Check out the entire CNN.com piece at http://www.cnn.com/2012/01/19/opinion/clark-southall-marine/index.html?hpt=hp_c2
It is encouraging that ocean bioacoustics is increasingly becoming “main-stream,” particularly in light of the fact that the reach of human noise is ever saturating into further reaches of the sea – requiring all of us to be better informed about how marine animals use their acoustic habitat, and how human noise is transforming it.
Written on November 23, 2011 at 2:44 pm, by mstocker
In an article in Marine Technology Review Shell Offshore is celebrating their first million barrels of oil drawn from wells off Brazil at a depth of nearly 2km. (6500 feet).
This depth translates into 185 atmospheres, or about 2600 lbs./in.2 so the feat represents a number of significant technological breakthroughs.
The article details some of these breakthroughs, including tying together wells scattered across a 20km field and separation of gas and oil with equipment mounted on the seafloor.
Of course this comes at some expense – some merely financial. But given the hostile environment, the extreme pressures, and the pumping of fluids and gasses at tremendous pressure differentials, we suspect that this seafloor mounted equipment is extremely noisy.
While we haven’t had a chance to measure the noise, one industry insider let me know that the separators “can be real screamers.”
We have no idea what the impacts of this noise will be on the marine habitat, but we would like to get an idea before all of this expensive equipment becomes a fixture in all future offshore oil fields.
Toward this end we are seeking funding to measure the noise in our Seafloor Processing Equipment Evaluation project. This will also be expensive, but worthwhile. Given our global thirst for oil, offshore oilfields will likely be expanding into ever deeper waters with unknown impacts on the ocean bio-acoustic environment.
Written on November 14, 2011 at 2:25 pm, by mstocker
Last week we attended an Acoustic Society conference in San Diego. This time I didn’t deliver a paper so it was mostly a reconnaissance trip – both to catch up with colleagues and to introduce Gwynn, our Digital Assets Manager to the field.
It is not a surprise that many of the bioacoustic papers that were presented involved the Arctic – both in terms of the acoustic ecology and habitat assessment, and in learning more about the animals in the area.
As the “ground zero” for global warming, the Arctic is changing extremely fast. Due to accelerated melt-back of the ice-cap entire expanses of the sea are being exposed to daylight which may not have seen the sun since the late Miocene period (over five million years ago). We all know that this is distressing the Polar Bears, but it is also threatening the Ribbon, Ringed, and Bearded seals, which live exclusively on sea ice.
Sound recordings are being made documenting animal vocalizations, baseline ambient noise, and the rise in human-generated noise. New sounds are being discovered, and new impacts are being noticed.
And this is none too soon.
This last summer Shell Oil was cleared to drill three exploratory wells in the Beaufort Sea, and just last Thursday the Department of Interior released a five year offshore drilling plan that includes opening up more leases in the Arctic.
Additionally, the National Marine Fisheries Service (NMFS) will soon be releasing the Draft Environmental Impact Statement for their five year Arctic plan for public comments. Given that the petroleum industry has been pushing to get their pipes in the Arctic waters we expect that there will be much to comment on.
We have been anticipating this and spent a good amount of time this last year with Dave Aplin of WWF, Michael Jasny of NRDC, and the good folks at Bean Creative developing a highly featured and interactive website focused on the impacts of offshore oil industry noise on Arctic habitats.
We’ll be launching this in the next few weeks to get everyone up to speed on the issues so that we can all provide focused and informed critiques of the NMFS plan.
Stay tuned; given the voracious appetite of the Oil Men we’ll need “all hands on deck” to protect the Arctic from their oily (and noisy) assaults.
Written on October 23, 2011 at 2:48 pm, by mstocker
Norwegian shipyard Ulstein recently delivered the first of two super seismic vessels to the geophysical company CGGVeritas. These vessels are designed to tow seismic survey airgun and streamer arrays for deepwater offshore fossil fuel exploration and are outfitted for arctic capability.
While it should not be a surprise, this is yet another reminder that as long as we run our civilization on oil, it will be found and extracted.
Seismic airgun surveys are among the loudest noises inflicted on marine environments, increasingly shown to compromise fisheries, spook whales away from important feeding and migratory behavior, and damage marine invertebrates.
Unfortunately these environmental costs are still considered ‘reasonable sacrifices’ in the balance of our energy needs. And while there are efforts being made to decrease the impacts of seismic exploration, it remains abundantly clear that our thirst for oil is the leading cause of planetary-scale environmental destruction; from the polluting byproducts of such as ocean noise, CO2, and other environmental toxins, to the robust military required to secure petroleum resources (and the raft of environmental assaults that militarism brings into play).
There are many strategies being advanced to decrease the impacts of fossil fuel on the planet, but the one thing we can all do is curb our consumption. This strategy can be supplemented by highlighting the collateral costs of a fossil fuel based economy.
As we look long and hard at these costs, the perceived costs of changing our energy habits (from transportation and consumption patterns, to sustainable power generation), the sacrifices made in the name of fossil fuel will no longer be considered reasonable.
Written on September 23, 2011 at 2:51 pm, by mstocker
One of the more vexing challenges in understanding the effects of noise on marine animals has to do with assessing the “sub-lethal” impacts that compromise biological functions. These include the impacts from noises that mask or hide biologically significant signals, noises that confuse or startle animals, and noises that just erode the acoustical qualities of a habitat (your humming refrigerator for example).
These noises don’t cause mass strandings, inflict tissue damage, or induce panic responses; rather they just increase stress levels. The synergistic impacts can include compromised immune response, changes in cardiovascular function, disturbed sleep cycles, changes in reproduction success and fetal development, and alter an array of adaptive behaviors.
These impacts are hard to correlate with sound exposure in natural environments because noise is just one of many stressors that animals suffer. And given that marine animals are mostly underwater and thus out of sight, it is hard to determine which stressor pushes the threshold most egregiously.
It has been only recently that instrument tags have been deployed on large animals that can help determine behavioral responses to specific noises, but the “synergistic” models remain for too complex in the marine environment to provide much evidence or clear data to help us sort out how chronic noises impact marine life.
That is perhaps until now.
On my return from a recent conference I was fortunate enough to be seated next to Joanne Blum, Dr. Veterinary Medicine, who is a consultant on many issues pertaining to lab environments for animal research.
In lab studies animals need to have a comfortable environment so that the preventable stresses of captivity do not skew the research results. Individual enclosures with clean air, dry bedding, and appropriate lighting are all worked into the design standards.
Increasingly “noise criteria” is also playing into the standards of enclosure design. And herein lays a rich legacy of studies on the impacts of chronic noise on biological functions – immune response, cardiovascular function, reproductive success, growth, and social behaviors.
Dr. Blum sent me an article link to ALN Magazine (a trade magazine for the “Animal Lab Industry”) and has mailed me a few other articles on the impacts of noise on lab animals. The wealth of useful information here is stunning, but not surprising. Off in our trajectory of marine bio-acoustics we don’t often consider where our work intersects a world where thousands of cages house rabbits, mice, and rats – which by the way all have excellent, broad-band hearing.
Regardless of your position on animal labs, the studies on noise impacts in controlled “vivarium” settings inadvertently provide a rich vein of data on non-lethal impacts of noise that is not found in the fields of marine mammology or fisheries health.
We will be excavating this new seam of data to inform our work, and allow us to gather a deeper understanding on how non-lethal levels of human generated noise can impact marine life.