High resolution biologging of breaching by the world’s second largest shark species

Abstract

Basking sharks, the world’s second largest fish, are endangered globally following two centuries of large-scale exploitation for their oily livers. In the northeast Atlantic, they seasonally gather in key sites, including the western Scottish Isles, where they feed on plankton, but their breeding grounds are currently completely unknown. Using high-resolution three-axis accelerometry and depth logging, we present the first direct records of breaching by basking sharks over 41 days. We show that basking sharks breach both during the night and day, starting at approximately 20 m depth and can breach multiple times in short succession. We also present early evidence of potential lateralisation in basking sharks. Given the energetic nature of breaching, it should have an important biological function, but this remains unclear.

An engineering perspective on the development and evolution of implantable cardiac monitors in free-living animals

“…Biologgers and tracking devices have been used for the past six decades and have provided the principal means of studying the interactions of many free-ranging animals with their environments, including both aquatic and terrestrial species [ 1 – 15 ]. Bears were among the first animals to be radio-collared, in part because their size enabled them to carry large battery packs unencumbered [ 16 ].…”