Important developments for naval sonar and impacts of pile driving

WDC was pleased to be asked to present at the first public forum (that I know of) on Sea Mammals and Active Sonar Symposium this week. You can see our contribution: sonar_symposium_2015.pdf

. This is the first of two big noise developments that I want to mention.

Patrick Miller, St Andrews Uni opening Sonar Symposium
Patrick Miller, St Andrews Uni opening Sonar Symposium

Whilst we are always impatient for developments to mitigate impacts to move more quickly, and for navies to develop more robust planning strategies, it was a very welcome step that European (Norway, Netherlands, UK, France, Germany, Denmark and Sweden) and US Navies gathered to discuss the management measures that they each undertake to protect marine life during military exercises. Such collaboration and focus on robust ways to mitigate behavioural  impacts, as well as injury, is a solid step forward.

Things are less encouraging on the pile driving front. We now have the first calculated evidence of the potential for harbour porpoise populations to be seriously affected by the accumulation of pile driving undertaken to build wind farms by all nations in the North Sea. The report states that the impacts of seismic surveys for oil and gas deposits are of the same order of magnitude as piling to install wind farms.

Harbour porpoise at surface
Harbour porpoise at surface

Impacts for both avoidance (disturbance) and injury have been presented. The results predicted average reduction in the North Sea porpoise population of 23% from 2016 to 2022 under one scenario provided in the scientific report. This study does not consider the additional impacts that porpoises and seals face other than pile driving or seismic surveys, such as those due to pollution, being caught in fishing nets or because of reductions in prey availability.

The UK and devolved governments need to seriously consider this important scientific report – and revise their current marine mammal mitigation policies accordingly. The existing German mitigation measures to reduce the noise at the source (which are much more advanced and precautionary than those adopted in the UK) lead to a major reduction in porpoises that are disturbed. To be able to meet our legal commitments, and to protect porpoises and seals from disturbance and injury, all countries in Europe need to make much more effort to reduce noise pollution at the source when building offshore wind farms – either by not piling or by using source reduction mitigations.  

WDC have continuously raised concerns about the potential impacts of pile driving to porpoises and other species. 

 

Tags: 
Pollution