The impact of animal platforms on polar ocean observation

The polar seas play a critical role in the climate system, forming important links between all oceans and between the atmosphere and deep sea. In addition, they support vital and unique ecosystems containing important living resources. Yet despite their importance, the physical environment and ecosystems of the polar regions are still under-sampled and, as a result, relatively poorly understood. At the 1st Symposium on Biologging Science in Tokyo, 2003, I reported on the initiation of the first large scale deployment of newly developed ocean profiling tags that used marine mammals as observation platforms (the SEaOS project). I expressed the hope that this approach would provide a rich new source of oceanographic data, creating a "win/win" opportunity with tags not only providing new insights into the behaviour of the equipped animals but also dramatically increasing ocean data availability in general. Now, almost a decade later, this hope has been realized. Instruments attached to animals have now delivered more than 270,000 CTD profiles, many from under-sampled parts of the polar regions where little or no oceanographic sampling had previously occurred. The data have been incorporated into global and regional models and have resulted in a range of publications on physical ocean processes as well as on the biology of the species that carried the tags. The magnitude of the contribution can be appreciated by querying the World Ocean Data Base (WOD). Animals have now provided approximately 70% of all oceanographic profiles south of 60 degrees S and are beginning to have a similar impact in the Arctic. The geographical coverage of the animal data fills in large tracts of previously under represented sectors of the polar oceans. Animals also have provided data during the polar winter when no other sources were available. As a comparison, the almost 900,000 CTD profiles provided by the Argo Program are considered to have revolutionized our understanding of the physical function of the oceans. The contribution of animal-borne CTDs to the WOD is increasing rapidly and is likely also to have a major impact, especially in higher latitudes. Incorporating these data into models and analyses in the future will dramatically improve our understanding of global physical oceanography as well as our understanding of polar ecosystems. (C) 2012 Elsevier Ltd. All rights reserved.