Influence of boat traffic on distribution and behavior of juvenile hawksbills foraging in a marine protected area in Roatan, Honduras

Marine protected areas (MPAs) have been implemented to reduce negative impacts of human activities on marine life. However, many MPAs do not address boat traffic and the behavioral alterations and physical injury to marine organisms that may result. Boating activities can alter activity patterns, increase stress, and lead to physical injury in various aquatic animals. The Sandy Bay West End Marine Reserve (SBWEMR) is a marine protected area in Roatan, Honduras, and a foraging area for the critically endangered hawksbill sea turtle (Eretmochelys imbricata). While direct capture by the public is forbidden, managing both increasing boat traffic, and its effect on hawksbill distribution and behavior are not addressed in the reserve's management plans. We aimed to quantify the amount of boat traffic moving throughout the SBWEMR and evaluate the effect of boat traffic on the presence, distribution, and behavior of juvenile hawksbills. Boat traffic throughout the reserve was quantified through a series of above-water and in-water surveys, while hawksbill behavior and presence were evaluated through in-water surveys using SCUBA. Spearman correlation suggested a moderate, but significant, positive correlation between boat intensity and hawksbill presence. Yet, a nonsignificant negative correlation was evident between boat intensity and behavior. Although data suggest that boat traffic may not disrupt or negatively alter in-water behavior, hawksbills are prone to the additional hazards of boat collisions and propeller strikes. To reduce the risks of injury and mortality, efforts should be made to continually monitor, regulate, and enforce vessel speeds in MPAs where hawksbills reside.