Tagging wild cetaceans : investigating the balance between more and less invasive techniques

Abstract

On-animal tags provide an incredible window into the world of cetaceans, allowing researchers to track movements across ocean basins and investigate fine-scale behavior deep below the surface. The earliest cetacean tags were Discovery marks developed by the British Colonial Office at the turn of the 20th century, and their influence continues to inform some of the implanted cetacean tags being deployed. Today, there are a wide variety of tags in use that can be broadly divided into two principal categories driven by the length of attachment required-disposable transmitting systems that are implanted in the animals and archival tags that must be recovered in order to collect the data. Archival tags typically use a non-invasive attachment with a release to get the data back. These tags provide essential information for conservation and management of these vulnerable species. In the United States, a broad suite of regulations protects cetaceans and other marine mammals. Welfare protection stems from the Animal Welfare Act and Conservation protection stems from the Marine Mammal Protection and Endangered Species Acts. To navigate this policy landscape, both regulators and Institutional Animal Care and Use Committees need to weigh the benefits of a tagging study against the potential for serious harm and evaluate whether a proposed method is the least harmful way to answer a scientific question. However, the effects of tagging wild cetaceans are not well-understood and difficult to compare, leading to challenges for objectively assessing proposals. In this environment of uncertainty, specific guidelines from professional societies would be helpful, but varying institutional and individual approaches to the balance between conservation and welfare will make consensus difficult. Given this context, we ought to employ the precautionary principle when evaluating impacts, interpreting guidelines and implementing them.