1. Echolocation detections and digital video surveys provide reliable estimates of the relative density of harbour porpoises. Issue 7 (28th February 2016) Authors: Williamson, Laura D.; Brookes, Kate L.; Scott, Beth E.; Graham, Isla M.; Bradbury, Gareth; Hammond, Philip S.; Thompson, Paul M. Editors: McPherson, Jana Journal: Methods in ecology and evolution Issue: Volume 7:Issue 7(2016:Jul.) Page Start: 762 Record Type: Journal Article View Content: Available online (eLD content is only available in our Reading Rooms) ↗