Marine Mammals and Multiple Stressors: Implications for Conservation and Policy

Marine mammals face many threats in the 21st century, and an introduction is provided here to these threats and some efforts to try to study their combined effects. This draws mainly on work undertaken under the auspices of the International Whaling Commission and, most recently, the US National Academies of Sciences, Engineering, and Medicine. The consideration of combined or cumulative effects is complex, but progress is being made, leading, potentially, to improved conservation policy. However, the pathway from better scientific understanding to real conservation action in the field is frequently fraught, and precautionary action to address stressors is advocated, including addressing those that might not even be of primary concern, to try to make populations more robust. In addition, the potential of veterinary sciences, including health studies of wild animal populations, to identify problems and stressors is noted, and a cross-fertilization between conventional conservation focuses and wild animal “welfare science” is encouraged. The problems inherent in addressing multiple stressors make the need for precaution in marine mammal matters all the greater. However, in order for decision makers to properly respond to complexity, they need to have the limitations of science clearly and honestly explained