December, 2009

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Communication signals threaten marine habitat

Sunday, December 13th, 2009

Commnuication and navigation beacons.

Back in the mid 1970’s Physical Oceanographer Walter Munk was evaluating the acoustical transmission characteristics of the ocean “sound channel” – an isothermal layer in the deep ocean that baleen whales use for long distance communication.

His visionary work in this field developed into a 1991 experiment called the “Heard Island Feasibility Test” which produced the first sound that was literally heard around the world – under water.

The utility of this ocean feature for long distance communication was something Dr. Munk had been advancing ever since 1978 when he proposed a “Sea Net” – an acoustic based ocean internet system that could be used – and heard around the world.

It was along this trajectory that the “Acoustic Thermography of Ocean Climates” (ATOC) was proposed, and then deployed in 1992 despite the misgivings many of us had about projecting very loud sounds throughout the entire Pacific Basin.

ATOC turned out to be relatively benign, but for me it was the harbinger of things to come; where all manner of acoustic signals would be used for research, military, and industrial communication –crowding out the important bio-acoustic signals of marine animals.

The signals and technologies continued to develop, and it was in 2000 with a US Navy proposal of a long distance sonar system called “SURTASS” (which would ensonify the entire ocean with military noise) that the public became aware of the problem.

Public hearings were conducted, lawsuits filed, and demonstrations ensued. It was in the midst of this gambit that the Bahamas Stranding occurred – alerting us all that despite the assurances of our Navy that there was indeed a problem.

It is the continuous association between military operations and marine mammal strandings that has kept the Ocean Noise Pollution issue in the public conversation. While most of this conversation orbits around military sonar and seismic surveys, the exponential advance of other acoustical communication and navigation signals threatens to seriously compromise the marine bio-acoustic habitat.

This link describes one such signal, but there are many others being developed and deployed for research, industrial, and military applications.

While some of these signals may not be pernicious – even while overlapping some odontocete communication and bio-sonar bands, it would be good to know this prior to saturating biologically significant habitat with sounds generated by expensive equipment.

Tools to make this determination is one of OCR’s banner projects which we hope to complete this year pending support from funding agencies.

When we do complete these tools it will be none too soon, as underwater communication systems are springing up like mushrooms all over the sea.

Stay tuned!

Posted in Fossil Fuel Industry, Noise Pollution, Ocean Life | No Responses »

The economies of gratitude….

Saturday, December 12th, 2009
Photo: Paul Nicklen, National Geographic

Photo: Paul Nicklen, National Geographic

An November 2009 article in Nature looks at non-kin cooperation models in animal societies. It examines reciprocity, mutualism, and manipulation in economic terms – with future expectations, biological expense, and cheating included in some of the trade values.

The overarching perspective is “why would an animal incur costs to their survival fitness unless there was some clear selection benefit to their behavior?”

Couching animal and human behavior strictly in economic terms has been an increasing trend over the last few decades. And while it does reveal expected value-exchange patterns and allows for repeatable assessments of behavioral incentives, it is a fairly narrow framework that comes at a pretty high “cost” – to extend the metaphor.

For example; it is this reductionist framing that justifies destruction of habitat because the economic value of the “extracted resources” outweighs the “environmental services” provided by the habitat.

Looking at biological systems as “economies” can suck the air out of environmental preservation discussions. I believe it also misses a fundamental reason for being alive.

Two compelling stories came up this month that illustrate this point; stories that would not fit well into the bio-economic models.

In one story a National Geographic photographer jumps into the water to film a leopard seal – a large deadly predator that is known to attack and eat humans. It turned out that the leopard seal “took pity” on this skin-and-bones visitor and spent the next few days capturing penguins and trying to feed him. In the second story a Humpback whale saves a Weddell seal from hungry Orcas with no clear biological incentives or expectations of reward.

Both of these examples of inter-species cooperation could be explained as “misdirected mothering instincts” – an explanation that is sort of a “work-around” when the economic model doesn’t fit very well.

Or it could be looked at as acts of gratitude: If you have something good going for you, it just feels nice to share it.

I hope that this finds you with lots to be thankful for, and abundant opportunities to share it with others.

Happy Thanksgiving!

Posted in Ocean Life, Uncategorized | No Responses »

The Neutrino and the Whale

Saturday, December 12th, 2009
photo: Brain Skerry

photo: Brain Skerry

A nicely written article in the Dec. 3 2009 issue  Nature reveals how a how a neutrino detection experiment conducted in the Mediterranean Sea by nuclear physicists actually uncovered an abundance of sperm whales.

The experiment involved placing hydrophones down 2000 meters below the surface; the idea being that these hydrophones could detect little pops from neutrinos – sub-atomic particles zipping in from deep space.

Marine Biologists Giovanni Pavan was brought in to help filter out the background noise. What they found though was a proliferation of biological sounds, and a surprising high density of Sperm Whale vocalizations – which ended up shifting the focus of the study to monitoring populations of sperm whales.

The article mentions that the Nuclear Physicists somehow thought that the deep ocean would be a “quiet test chamber” for their studies. I find it telling that some of the smartest guys in the room (nuclear physicists) would be so siloed in their field that they would lose track of the fact that the ocean is teaming with ‘biologicals.’

This speaks volumes about our education model that focuses on specialization. It makes me worry about what I am missing when I scan the field I inhabit. But this tale also helps me cultivate more patience for those folks who “can not seem to grasp” the importance of our mission of preserving the ocean’s bio-acoustic sanctity.

This little sound sample is of the “carpenter fish” – an old mariner’s name for sperm whales, representative of what the scientists heard.

Posted in Noise Pollution, Ocean Life | 1 Response »