Impacts of Human Disturbance in Marine Mammals: Do Behavioral Changes Translate to Disease Consequences?

Abstract

AbstractHumans 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) using a mathematical modeling framework to examine how these behavioral changes might influence potential epidemics. Human disturbances can influence marine mammal behavior in ways that increase 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 (California sea lions, Zalophus californianus; Australian humpback dolphins, Sousa sahulensis; killer whales, Orcinus orca; Indo-Pacific bottlenose dolphins, Tursiops aduncus), 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 and populations 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.KeywordsBehaviorContact networksEpidemiological modelHuman impactsMarine mammalWildlife disease