Reference

Hagihara R, Jones RE, Grech A, Lanyon JM, Sheppard JK & Marsh H (2014). Improving population estimates by quantifying diving and surfacing patterns: a dugong example. Marine Mammal Science 30(1):348–366.
Hagihara R, Jones RE, Sobtzick S, Cleguer C, Garrigue C & Marsh H (2018). Compensating for geographic variation in detection probability with water depth improves abundance estimates of coastal marine megafauna. PloS One 13(1):e0191476.