Loggerhead turtles killed by vessel and fishery interaction in Virginia, USA, are healthy prior to death

• Published in: Marine ecology. Progress series (Halstenbek) 2016-08, Vol.555, p.221-234
• Main Authors: Barco, Susan, Law, Mac, Drummond, Bridgette, Koopman, Heather, Trapani, Christina, Reinheimer, Shannon, Rose, Sarah, Swingle, W. Mark, Williard, Amanda
• Format: Article
• Language: English
• Subjects: Marine
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps11823

Human-induced mortality of marine animals is a complex issue and the health of animals prior to human interaction is often questioned. We reviewed 74 cases of loggerhead turtles in the mid-Atlantic region of the US to determine whether fresh, dead loggerhead turtles that died from acute vessel or fishery interaction (acute VI/FI) were healthy animals prior to human-induced mortality. We used the presence of significant underlying pathology to determine health status and compared the body condition and adipose stores with turtles that died from other causes. We qualitatively and quantitatively assessed body condition using images, morphometrics, mass dissection data, % lipid and % triacylglycerol in the adipose tissue. We used the quantitative indices to validate the qualitative index. Acute VI/FI turtles were significantly less likely to have significant lesions indicating compromised health compared with turtles that died from other causes (χ² = 12.9012, df = 1, p = 0.0003). There was a significant relationship between qualitative body condition and cause of death category, with acute VI/FI turtles more likely to exhibit normal body condition than turtles that died from other causes (χ² = 18.879, df = 2, p < 0.0001). Values for 3 quantitative indices were significantly higher for acute VI/FI turtles compared with other causes of death, while 3 others were not different across turtles, most likely because there were some healthy turtles in the ‘other’ cause of death category. Our results suggest that the majority of acute VI/FI loggerhead turtles represented normal, healthy turtles in the population and were not compromised prior to human-induced mortality.