Vessel speed increases collision risk for the green turtle Chelonia mydas

Hazel, Julia, Lawler, Ivan R ., Marsh, Helene, and Robson, Simon (2007) Vessel speed increases collision risk for the green turtle Chelonia mydas. Endangered Species Research, 3 (2). pp. 105-113.

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Vessel collisions contribute to the anthropogenic mortality of several threatened marine species including turtles, manatees, dugongs and whales, but scant data exist to inform the design of optimal mitigation measures. We conducted a field experiment to evaluate behavioural responses of green turtles Chelonia mydas to a research vessel approaching at slow, moderate or fast speed (4, 11 and 19 km h–1, respectively). Data were recorded for 1890 encounters with turtles sighted within 10 m of the research vessel's track. The proportion of turtles that fled to avoid the vessel decreased significantly as vessel speed increased, and turtles that fled from moderate and fast approaches did so at significantly shorter distances from the vessel than turtles that fled from slow approaches. Our results imply that vessel operators cannot rely on turtles to actively avoid being struck by the vessel if it exceeds 4 km h–1. As most vessels travel much faster than 4 km h–1 in open waters, we infer that mandatory speed restrictions will be necessary to reduce the cumulative risk of vessel strike to green turtles in key habitats subject to frequent vessel traffic.

Item ID: 8059
Item Type: Article (Research - C1)
ISSN: 1613-4796
Keywords: green turtles; Chelonia mydas; behaviour; collision risk; collision avoidance; vessel speed; Go Slow zones
Date Deposited: 01 Feb 2010 22:28
FoR Codes: 05 ENVIRONMENTAL SCIENCES > 0502 Environmental Science and Management > 050211 Wildlife and Habitat Management @ 33%
06 BIOLOGICAL SCIENCES > 0602 Ecology > 060201 Behavioural Ecology @ 33%
06 BIOLOGICAL SCIENCES > 0608 Zoology > 060801 Animal Behaviour @ 34%
SEO Codes: 96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960802 Coastal and Estuarine Flora, Fauna and Biodiversity @ 70%
96 ENVIRONMENT > 9605 Ecosystem Assessment and Management > 960502 Ecosystem Assessment and Management of Antarctic and Sub-Antarctic Environments @ 30%
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