Data is presented as detection-positive days (DPD) and detection-positive hours (DPH) for both species. DPD = The detection of echolocation clicks per day (1 = Detection-positive, 0 = Detection-negative) DPH = The number of hours echolocation clicks are detected per day Nall = Total number of clicks detected per day Ndays = Total number of days recorded PorpDPH_median = Median porpoise detection-positive hours for each site DolDPH_median = Median dolphin detection-positive hours for each site Proportion_PorpDPD = Proportion of porpoise detection-positive days (out of total days recorded, Ndays) Proportion_DolDPD = Proportion of dolphin detection-positive days (out of total days recorded, Ndays) Data has been prepared as ArcGIS maps showing median DPH and proportion of DPD for both species across all 30 sites. It has also been converted to be viewed on Marine Scotland Maps , and for direct download as a spread sheet (.csv)