We now know what we don’t know – Report from AN2013

When ocean noise pollution first came up on the public sonar there were only a few handfuls of people engaged in the issue – all acrimoniously divided between the (mostly) industry/Navy noise-makers and the environmental/conservation biology interests who just wanted the noisemakers to shut-up.

The noise-makers argued that the enviro/conservationists didn’t know what they were talking about, and the enviro/conservationists knowing that little was known by anybody about the subject invoked the “precautionary principle,” which holds that if an action is suspected of causing harm and lacks scientific consensus that it doesn’t, the burden of proof that the action is harmless falls upon those proposing the action.

That was over a decade (and three Aquatic Noise conferences) ago. Many tragic marine mammal strandings have occurred since then, and many predicted disasters did not. It turns out that sound, like the ocean, is infinitely complex. And as more folks have joined in to fill in our gaps in knowledge we are finding more gaps and ‘expanding questions’ about how acoustical energy propagates in the complex thermal, multi-density, turbulent physio-chemistry of the ocean, and how the propagation is complicated by the diverse frequency and time domain characteristics of the energy source, and how the biological receivers – from jellyfish to lobsters, flounders to sharks, and crabs to great whales pull what they need out of this acoustical soup.

The conveners of the event again went to great lengths to assure that a healthy range of stakeholder’s views were represented and that a robust number of the most qualified voices were attending. It became quite clear that despite the regulator’s hopes to the contrary, there will never be a concise set of numbers expressing mitigation thresholds. It even became clear that some of the mitigation values currently in use are of questionable utility.

Hungarian Parliament

Hungarian Parliament building in Budapest *

But far from being hopeless; when so many experts across the field can convene and converse it can only deepen the inquiry. So while we are still far from solving the problems of noise impacts on marine life we are getting a clear – and perhaps more importantly a common idea about how far away we are.

If we won’t have a concise set of regulatory guidelines anytime soon, ocean practices are nonetheless being informed and modified by our deeper understanding of the impacts and the influences of medium in which they occur. While not exactly the precautionary principal in action, the elements of the philosophy are finding a place at the table.

*With 20 km of staircases, 691 rooms, and over 700 spires this near-incomprehensible building nonetheless holds together, mostly – as there is rarely a time when scaffolding is not shoring up some side or other due to subsidence and other geological dynamics.