Journal Article

Diving behaviour of freshwater finless porpoises (<i>Neophocaena phocaenoides</i>) in an oxbow of the Yangtze River, China

Tomonari Akamatsu, Ding Wang, Kexiong Wang, Zhuo Wei, Qingzhong Zhao and Yasuhiko Naito

in ICES Journal of Marine Science

Published on behalf of ICES/CIEM

Volume 59, issue 2, pages 438-443
Published in print January 2002 | ISSN: 1054-3139
Published online January 2002 | e-ISSN: 1095-9289 | DOI: http://dx.doi.org/10.1006/jmsc.2001.1159
Diving behaviour of freshwater finless porpoises (Neophocaena phocaenoides) in an oxbow of the Yangtze River, China

More Like This

Show all results sharing these subjects:

  • Environmental Science
  • Marine and Estuarine Biology

GO

Show Summary Details

Preview

Dive-depth and swim-speed of a juvenile and an adult free-ranging, Yangtze finless porpoises (Neophocaena phocaenoides) were observed using velocity-time-depth recorders in an oxbow of the Yangtze River. In total, 8222 individual dives were recorded over 59 hours. Two dive types, deep-dive (≥2.7 m) and shallow-dive, were recognized. Horizontal travel distances of two finless porpoises in a day were 94.4 km and 90.3 km, which were longer than those of oceanic relative species (harbor porpoises, Phocoena phocoena). Although the shallow water limited the maximum dive-depth, dive-duration, and bottom-time of finless porpoises were similar to the harbor porpoises. A sudden drop of swim-speed below 0.25 m s−1 was frequently observed nearby the maximum dive-depth. This seemed to indicate “turning around” behaviour, possibly during prey pursuit.

Keywords: by-catch; collision with commercial vessel; data logger; diving behaviour; freshwater; porpoise

Journal Article.  0 words. 

Subjects: Environmental Science ; Marine and Estuarine Biology

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.