Vessel noise prior to pile driving at offshore windfarm sites deters harbour porpoises from potential injury zones

Efforts to meet climate change targets are resulting in rapid and global expansion of offshore windfarms. In many regions, development areas are also used by protected marine mammals, requiring the assessment and mitigation of any risk of injury during construction and operation. For small cetaceans such as the harbour porpoise, there is particular concern over the risk of injury from impulsive noise should individuals remain within near-field injury zones during the installation of pile driven turbine foundations. Currently, this risk is assessed by comparing predicted noise levels at the start of piling with baseline estimates of animal density, which are, in turn, based on data collected at least one year earlier. However, vessel-based preparation work immediately prior to piling may displace animals, thus reducing any risk of injury when pile-driving begins. We investigated the effects of pre-piling activities on local soundscapes and harbour porpoise occurrence during the construct..., Passive Acoustic Monitoring (PAM) data were collected using echolocation click detectors (CPODs) and underwater noise recorders (SoundTrap). These data were processed and the presence/absence of harbour porpoise clicks and mean Sound Pressure Levels were summarised by hour relative to piling (HRP), per deployment, site and in relation to piling events. 
Automated Identification System vessel-trcking data were purchased, processed and the vessel intensity, mean and minimum distance from vessels to PAM devices were summarised per HRP. 
Daily engineering records were provided by the windfarm developpers and used to calculate the proportions of activities conducted by the piling vessel per HRP and windfarm and estimate the time of arrival of the piling vessel at construction sites. , R can be used to open and run the R scripts and the R project. The .txt files can be opened with Notepad but can also be called directly in R using the R scripts. , \# Title of Dataset:\"Variation in soundscapes and harbour porpoise occurrence prior to pile\-driving at two offshore windfarms\"
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Passive Acoustic Monitoring data collection was funded by the Marine Mammal Monitoring Programmes
for the construction of the Beatrice and Moray East offshore windfarms.
Contact for queries is Aude Benhemma-Le Gall, [e-mail]
Automated Identification System vessel-tracking raw data are not shared in this repository, as the University of Aberdeen has signed a Data Licence Agreement.
However, summaries of these vessel data are provided as txt file.

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\#\# R scripts
Name - Description
\#\#\# 1\_Benhemma\-Le\_Gall\_Allocate\_HRP\_to\_piling\_timeline\.R
Based on the piling timeline of both the Beatrice and Moray East offshore windfarms, we identifed piling bouts of at least 12 hours,
filtered the subset of turbine locations where piling bouts had at least a three-day gap between the end of piling at the previous turbine location
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