Use observers on board vessels to detect mammals and allow vessel course or speed to be altered
Overall effectiveness category No evidence found (no assessment)
Number of studies: 0
Background information and definitions
Trained, dedicated observers on board vessels may be used to alert crew to the presence of marine or freshwater mammals within shipping lanes so that avoidance measures can be taken, such as slowing the vessel or changing course. Dedicated observers have been found to detect more marine mammals than standard vessel crew and often at larger distances from the vessel (Weinrich et al. 2010). However, the ability of observers to detect mammals will depend on the environmental conditions and speed of the vessel, among other factors, and collisions may still occur if mammals are not seen or seen too late to take avoidance measures (Wiley et al. 2016).
For similar interventions, see Use real-time automated tools on board vessels to detect mammals and allow vessel course or speed to be altered and Use remote tools to detect mammals in an area and allow vessel course or speed to be altered.
Weinrich M., Pekarcik C. & Tackaberry J. (2010) The effectiveness of dedicated observers in reducing risks of marine mammal collisions with ferries: A test of the technique. Marine Mammal Science, 26, 460–470.
Wiley D.N., Mayo C.A., Maloney E.M. & Moore M.J. (2016) Vessel strike mitigation lessons from direct observations involving two collisions between noncommercial vessels and North Atlantic right whales (Eubalaena glacialis). Marine Mammal Science, 32, 1501–1509.