Current address: Biology and Marine Biology, UNCW, 601 S. College Rd., Wilmington, North Carolina 28403, U.S.A.
FORENSIC METHODS FOR CHARACTERIZING WATERCRAFT FROM WATERCRAFT-INDUCED WOUNDS ON THE FLORIDA MANATEE (TRICHECHUS MANATUS LATIROSTRIS)
Article first published online: 21 DEC 2006
Marine Mammal Science
Volume 23, Issue 1, pages 110–132, January 2007
How to Cite
Rommel, S. A., Costidis, A. M., Pitchford, T. D., Lightsey, J. D., Snyder, R. H. and Haubold, E. M. (2007), FORENSIC METHODS FOR CHARACTERIZING WATERCRAFT FROM WATERCRAFT-INDUCED WOUNDS ON THE FLORIDA MANATEE (TRICHECHUS MANATUS LATIROSTRIS). Marine Mammal Science, 23: 110–132. doi: 10.1111/j.1748-7692.2006.00095.x
- Issue published online: 21 DEC 2006
- Article first published online: 21 DEC 2006
- Received: 17 February 2006Accepted: 20 August 2006
- forensic methods;
- watercraft-induced wounds;
- Florida manatee;
- Trichechus manatus latirostris;
- propeller wounds;
Watercraft-related mortality represents 1,253 (24.9%) of 5,033 Florida manatee (Trichechus manatus latirostris) deaths recorded between 1 January 1979 and 31 December 2004. Wound patterns generated by collisions with watercraft are diagnostic. Sets of cuts and scrapes that are roughly equidistant and perpendicular to the direction of vessel travel are consistent with lacerations made by propeller blades. From these lesions, estimates of propeller diameter, pitch, rotation, and direction of travel may be obtained. Considerable overlap of propeller sizes and pitches on different size vessels, common use of counter rotation propellers, and numerous other complicating factors may confound efforts to accurately predict vessel size and type from propeller wounds. Of the more than one million watercraft registered in Florida, 98% are ≤12.2 m (40 ft), yet watercraft 5.3–36.6 m (17.5–120 ft) are known to have killed manatees. Analysis of a 5-yr subset of mortality data suggests that a disproportionate number of propeller-caused watercraft-related mortalities could be attributed to propeller diameters ≥43.2 cm (17 in.), inferring that these were caused by watercraft ≥12.2 m (40 ft).