Making a noise about noise!
WDC delivered a keynote presentation – – on progress that has been made in the last 20 years (since we have been working on the issue) to reduce marine noise pollution at the Oceanoise conference this week.
The conference included sessions on efforts to reduce noise pollution, particularly international shipping and seismic surveys. WDC’s talk focused on European waters, and highlighted that we need to set noise limits under the EU Marine Strategy Framework Directive in order to achieve Good Environmental Status by 2020. We identified the ways in which some shipping, oil and gas companies, militaries and marine renewable energy developers in German waters have made efforts to reduce their impacts to whales and dolphins and other marine life.
We presented analysis showing that German mitigation measures during pile driving construction may reduce harbour porpoise population declines from a 12.6% to 0.2% (work presented by Ursula Verfuss to a WDC Noise Workshop at the International Marine Conservation Congress in 2014). Impacts of all pile driving across the North Sea on harbour porpoises were also presented (de Jong), where applying noise limits dramatically reduced impacts. The backdrop to this is that post mortem of stranded and bycatch data show that harbour porpoises in European waters are not healthy (Siebert).
A number of studies demonstrated the behavioural impacts of various noise sources on different marine species. Focusing on cetaceans, these included changing call rates of bowhead whales in response to seismic airguns in the Arctic Beaufort Sea (Nations), large vessel impacts on baleen whales (Risch) and the disappearance of Northern Bottlenose Whales from areas where military sonar were played to them (Miller) – it seems that bottlenose whales, like other beaked whales, are particularly sensitive to noise pollution. We also heard how the US military is improving its monitoring of dolphin distribution following the deaths of 3 common dolphins during explosions (Lammers). Different types of disturbance affect pilot whales in different ways (Visser) and evidence of noise-induced hearing loss in stranded pilot whales (Morrell) were presented. However we need to take care that cetaceans which don’t respond (non-displacement) may be ‘tolerating’ noise because they do not have a choice (Nowacek).
An Aberdeen University and Natural Power study included expert input to calculate that construction of wind farms in east coast Scottish waters will not have a long term impact on the Moray Firth bottlenose dolphins (Grellier). Whilst CEFAS (Merchant) told us that noise levels were underestimated close to the source during the expansion of Nigg port, in the inner Moray Firth Special Area of Conservation, where the risk of injury and disturbance for bottlenose dolphins is highest.
There were also talks on testing the effectiveness of ramp up for sonar (Wensveen; von Benda Beckmann) and seismic (Noad) although how the energy is ‘ramped up’ is important to consider (Cato).
Other highlights included an update on the US Ocean Noise Strategy, and polar and riverine sessions. Resulting discussions and recommendations will be written up and returned to so we can assess progress at a future conference. All in all a very useful and productive noise conference, thanks to Laboratory of Applied Bioacoustics, Technical University of Catalonia, BarcelonaTech (UPC).