Melissa Ann Collier, Sania Ali, Janet Mann, Shweta Bansal

Humans have been altering wildlife habitats and wildlife behavior worldwide at an accelerated pace in recent decades. While it is well-understood how human-induced behavioral changes affect infectious disease risk in terrestrial wildlife, less is known in marine life. Here we examine this link in marine mammal populations by (1) conducting a systematic literature review to determine how human disturbances change marine mammal behavior in ways that can impact disease spread, and (2) examining how these behavioral changes might influence potential epidemics using a mathematical modeling framework. We find that human disturbances can influence marine mammal behavior in a way that increases their exposure and susceptibility to pathogens, as well as their infectivity, or ability to effectively shed pathogens and infect conspecifics. When these changes to exposure, susceptibility, and infectivity are applied in four different marine mammal case studies, epidemics are predicted to be larger and more likely to occur. Considering the rate at which human disturbance is increasing in the marine environment, and the large number of marine mammal species that are endangered or
on the verge of extinction, we advocate for the careful consideration of the direct and indirect impact of human disturbance on marine mammal health.