Abstract

Temperature and depth logging tags were implanted into adult eels released on Atlantic west coasts of France and Ireland to study their oceanic migration behavior. For three of the tags, 25 to 256 days after release there was a dramatic rise in temperature from 10 degrees C to 36 degrees C and the dive profile changed from depths of 300-1000 m to repeated ascents to the surface. This indicated that the eels carrying the tags had been eaten by a mammalian predator. Two of the tags had sufficient sampling rate to resolve the dives in detail. They recorded a total of 91 dives to maximum depths of 250-860 m lasting 11-12 min and with surface intervals of 5-7 min. More than two thirds of the dives included a rapid descent from approximately 500 m to 600-700 m. From this we infer that the predator was most likely a deep-diving toothed whale. The dives logged while the tags were inside the predator revealed that the temperature usually decreased during dives, and increased again during surface periods. The temperature drops during dives were probably caused by the ingestion of prey or water. These observations provide insights into the behavior of toothed whales foraging in the mesopelagic zone. (C) 2014 Elsevier Ltd. All rights reserved.

Keywords

Archival tag; Eel; Predation; Diving behavior; Toothed whale predator

Published in

Deep Sea Research Part I: Oceanographic Research Papers
2014, Volume: 86, pages: 32-38
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

SLU Authors

• Westerberg, Håkan

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Fish and Aquacultural Science


Publication identifier

DOI: https://doi.org/10.1016/j.dsr.2014.01.003

Permanent link to this page (URI)

https://res.slu.se/id/publ/68184