Atlantic sturgeon Acipenser oxyrinchus surfacing behaviour |
| |
| Authors: | L M Logan‐Chesney M J Dadswell R H Karsten I Wirgin M J W Stokesbury |
| |
| Affiliation: | 1. Department of Biology, Acadia University, Wolfville, NS, Canada;2. Department of Mathematics and Statistics, Acadia University, Wolfville, NS, Canada;3. Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY, U.S.A. |
| |
| Abstract: | Atlantic sturgeon Acipenser oxyrinchus surfacing behaviour was investigated in Minas Basin (45° 20′ N; 64° 00′ W) and the Bay of Fundy with pop‐up satellite archival tags (MiniPAT) measuring physical variables (pressure, temperature, light ) . Of six tags deployed during June and July, five provided pop‐up locations and two were recovered after c. 4 months. Analysis of recovered archival data revealed that the frequency of surfacing events was highest (78·9%) when A. oxyrinchus were in Minas Basin at depths <10 m. Surfacing frequency decreased substantially when fish migrated into greater depths of the Bay of Fundy (>40 m). The tidal cycle in Minas Basin had a significant relationship to surfacing frequency, with the most surfacing events (49·5%) occurring on the flood tide, from mid‐ to high‐tide. Surfacing events ranged from 0–12 a day and the maximum number occurred between 2300 and 0300 hours. Maximum surfacing ascent speeds ranged from 0·50 to 4·17 m s?1 and maximum descent speeds ranged from 0·17 to 3·17 m s?1. Buoyancy control, by gulping air to inflate the gas bladder, is proposed as the main reason for surfacing behaviour in A. oxyrinchus. |
| |
| Keywords: | buoyancy control depth effects pop‐up archival tags surfacing frequency swim speeds tidal effects |
|
|
