Stress-Related Behaviors and Risks Associated with Human-Odontocete Interactions: A Review and Assessment

Frohoff, T.G.
TerraMar Research, 321 High School Rd., NE, PMB 374, Bainbridge Island, WA 98110, USA

A review of literature documenting odontocete behaviors potentially indicative of stress associated with 'sociable' interactions with humans over the last century was conducted. Stress-related behaviors and the risks of impact to the animals involved in these interactions were assessed. Sociable interactions were characterized by the animals engaging in sustained or repeated close contact with swimmers, waders, or boaters. In this review of 59 documents, a total of 177 reports of stress-related odontocete behaviors observed in the context of sociable human interaction were noted. Of these, 107 (60%) were documented for solitary animals. Eighty-seven (almost 50%) of the total reports involved swimmers only, indicating that swimmers alone can exert impacts to odontocetes under a variety of conditions. This assessment revealed that even well-intentioned interactions with odontocetes can be associated with serious impacts to the animals, some of which are long-term and life threatening to individuals as well as to populations. Various aspects of human activity and target animal characteristics were identified as important factors in evaluating the potential for swimmer and boater impact. Identification of these factors appears to be a valuable tool for minimizing impacts when incorporated into management programs. In light of the proliferation of programs facilitating interaction with cetaceans, the existing research indicates that a precautionary approach to management of these activities is warranted so that the burden of proof lies with those who want to interact with the animals instead of those who want to protect them.