Tools to Compare Diving-Animal Kinematics With Acoustic Behavior and Exposure

Abstract

Intense international concern has arisen over the potential effects of anthropogenic sound on protected marine wildlife. To study this issue presents a challenge, however, because marine animals in captivity form a limited sample set that cannot always be extrapolated to wild populations, while those in the wild spend the majority of their time submerged and out of sight of researchers. Thus instrumentation to monitor the behavior and sound exposure of wild, free-ranging marine animals is essential. Broadband acoustic recording tags offer a promising avenue for studying the relationship between behavior and sound exposure for free-ranging animals. Since 1995, when the first combined broadband-acoustic and behavior recorders were deployed with northern elephant seals (Burgess et al., 1998) such tags-predominantly the DTAG (Johnson and Tyack, 2003) and the Bioacoustic Probe (Burgess, 2000; Figure 1)-have seen extensive use in the study of baleen whales, sperm whales, and seals (e.g., Insley et al., 2007; Miller et al., 2004; Oleson et al., 2007). These studies have generated a dramatic quantity of acoustic, depth, and orientation data, and as combined acoustic/behavior tags become increasingly available the amount of data will continue to grow. This rapid expansion of data will not, however, support the commensurate expansion of study and understanding unless the wider research community is equipped to process and interpret those data effectively.