Search

Underwater noise pollution from impulsive sources (e.g. explosions, seismic airguns, percussive pile driving) can affect marine fauna through mortality, physical injury, auditory damage, physiological stress, acoustic masking, and behavioural responses. Given the potential for large-scale impact on marine ecosystems, some countries are now monitoring impulsive noise activity, coordinated internationally through Regional Seas Conventions. Here, we assess impulsive noise activity in the Northeast Atlantic reported during 2015–2017 to the first international impulsive noise register (INR), established in 2016 under the OSPAR Convention. Seismic airgun surveys were the dominant noise source (38%–56% of annual activity) and declined by 23% during 2015–2017. Reported pile driving activity increased 72%. Explosions and sonar/acoustic deterrent devices both had year-on-year increases in reported activity. Some increases were attributable to more comprehensive reporting in later years. We discuss utilising the INR for risk assessment, target setting, and forward planning, and the implementation of similar systems in other regions.

The Joint Monitoring Programme for Ambient Noise North Sea (JOMOPANS) aimed to develop a framework for managers, planners and other stakeholders to incorporate the effects of ambient noise in their Good Environmental Status (GES) assessment of the North Sea. This was accomplished by generating spatial maps of the anthropogenic and natural soundscapes, modelled from ambient noise measurements collected around the North Sea by the different member states in 2018 and 2019. We focused on the depth-averaged sound pressure level (SPL) of the one-third octave (base-10) bands between 10 Hz to 20 kHz in one second snapshots, viewed in monthly percentiles. From these data, we can better understand the criteria and noise thresholds necessary to achieve GES in the North Sea. Part of this effort was to develop a GES Tool, which would allow users to view the modelled noise maps by noise type (ship type, weather, etc.), protected areas designated by various EU agencies, and habitats used by soniferous or sound sensitive species. The tool computes and displays areas where there is a large overlap between anthropogenic noise and key marine species. This tool aims to help policy makers evaluate measures and thresholds put forward to achieve GES.

Monitoring of the environmental effects of a harbour extension and the compensation measures is a very complex task. The Voordelta area has high natural values, but is also of high economic importance. To implement a monitoring strategy for this area a multidisciplinary consortium has been formed, consisting of a number of institutes and companies. A central data management facility was set up for data storage and management. This chapter illustrates the data management approach using the Voordelta monitoring programme for the years 2004 to 2013. A central data management facility was set up for data storage and management. A repository gives access to raw data files to all team members. From the analysis of the raw data a number of information products have been developed and disseminated to the authorities and the public through Google Earth. It will be shown, that the presence of a strong multidisciplinary team and good collaboration is the key to success in this complex programme. The way the data have been managed supports this process enormously.

Spatial cross-correlation beamsteering with a T-shaped sparse array can provide an efficient procedure to identify the directions and to obtain the emission levels of multiple uncorrelated noise sources. The procedure can be applied to stationary or moving sources. It provides two-dimensional image resolution equivalent to that of a full array, but requires significantly fewer microphones. This results in substantially reduced requirements for data acquisition and signal processing, with a material cost reduction. Simulation, laboratory measurement, and field measurement of a train moving at high speed illustrate application of the procedure.