2016-2018, Newcastle University, Blyth Demonstration Site, Acoustic monitoring of Cetaceans series https://portal.medin.org.uk/portal/start.php?tpc=015_c7be7a8a-21d1-4701-b0ba-7a5ae90933bc The occurrence of common bottlenose dolphin (Tursiops truncatus), white-beaked dolphin (Lagenorhynchus albirostris), and harbour porpoises (Phocoena phocoena) was assessed over a three-year period at the Blyth Offshore Demonstrator (BOD) site off Blyth, Northumberland. Occurrence data were collected through the use of passive acoustic monitoring (C-PODs) at nine locations. This final report examines the data collected between March to October for the years 2016, 2017, and 2018, representing the pre-, during- and post-construction phases of the commissioned five turbine array. Across the course of this study, 101,675 complete hours of data were collected. Analyses indicate significant spatial and temporal (across daily and intra-annual cycles) preferences for both porpoises and dolphins. Further significant predictors of occurrence included; vessel sonar occurrence, dolphin occurrence, tidal height, tidal change between hours and year for porpoises; and vessel sonar occurrence, porpoise occurrence, and year for dolphins. Analyses also found month, year, and vocal activity to be significant predictors of the relative foraging occurrence of porpoises in the area. With regard to the potential impacts of construction activity on both porpoise and dolphin occurrence in the BOD site, the present study demonstrated no compelling evidence for any long-term, large-scale negative impacts on either species group. However, there was a lower occurrence of dolphins during the construction year (2017) compared to the pre-construction year (2016) indicating that dolphins may have avoided the area during construction. The post-construction year (2018) had higher dolphin occurrence compared to both 2016 and 2017 indicating that any avoidance was temporary. 20250304T09:32:49