Markov chains are used to assess how the behaviour of marine mammals changes across a range of variables (depth, group size, presence of calves or vessels…). Results indicate bottlenose dolphins spend less time feeding and resting, but more time milling and socialising in the presence of vessels. This work follows from a Massey unviersity study conducted in 2016 – https://www.doc.govt.nz/globalassets/documents/conservation/marine-and-coastal/bottlenose-responses-dolphin-vessel-activity-northland.pdf