Divert shipping routes
Overall effectiveness category No evidence found (no assessment)
Number of studies: 0
Background information and definitions
Diverting shipping routes away from important areas for marine and freshwater mammals may reduce the risk of lethal collisions (Vanderlaan et al. 2009, van der Hoop et al. 2012, Chion et al. 2018). Diversions may be permanent or temporary (e.g. seasonal or in response to mammal sightings), mandatory or voluntary, and may apply to all vessels or to certain vessel types or sizes. Careful planning may be required as diverting shipping routes to avoid one species could increase the collision risk for other species in new areas (Redfern et al. 2013). Enforcement may also be required if compliance is low.
This intervention is often combined with vessel speed restrictions, see Set and enforce vessel speed limits.
Chion C., Turgeon S., Cantin G., Michaud R., Ménard N., Lesage V., Parrott L., Beaufils P., Clermont Y. & Gravel C. (2018) A voluntary conservation agreement reduces the risks of lethal collisions between ships and whales in the St. Lawrence Estuary (Québec, Canada): From co-construction to monitoring compliance and assessing effectiveness. PLOS ONE, 13, e0202560.
Redfern J.V., Mckenna M.F., Moore T.J., Calambokidis J., Deangelis M.L., Becker E.A., Barlow J., Forney K.A., Fiedler P.C. & Chivers S.J. (2013) Assessing the risk of ships striking large whales in marine spatial planning. Conservation Biology, 27, 292–302.
van der Hoop J.M., Vanderlaan A.S.M. & Taggart C.T. (2012) Absolute probability estimates of lethal vessel strikes to North Atlantic right whales in Roseway Basin, Scotian Shelf. Ecological Applications, 22, 2021–2033.
Vanderlaan A.S.M. & Taggart C.T. (2009) Efficacy of a voluntary area to be avoided to reduce risk of lethal vessel strikes to endangered whales. Conservation Biology, 23, 1467–1474.