Publication Date:
2022-05-26
Description:
Author Posting. © Royal Society, 2005. This article is posted here by permission of Royal Society for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society of London B 272 (2005): 355-363, doi:10.1098/rspb.2004.2964.
Description:
Novel observations collected from video, acoustic and conductivity sensors showed that Antarctic fur seals
consistently exhale during the last 50–85% of ascent from all dives (10–160 m, n 〉 8000 dives from 50
seals). The depth of initial bubble emission was best predicted by maximum dive depth, suggesting an
underlying physical mechanism. Bubble sound intensity recorded from one seal followed predictions of a
simple model based on venting expanding lung air with decreasing pressure. Comparison of air release
between dives, together with lack of variation in intensity of thrusting movement during initial descent
regardless of ultimate dive depth, suggested that inhaled diving lung volume was constant for all dives. The
thrusting intensity in the final phase of ascent was greater for dives in which ascent exhalation began at a
greater depth, suggesting an energetic cost to this behaviour, probably as a result of loss of buoyancy from
reduced lung volume. These results suggest that fur seals descend with full lung air stores, and thus face
the physiological consequences of pressure at depth. We suggest that these regular and predictable ascent
exhalations could function to reduce the potential for a precipitous drop in blood oxygen that would result in
shallow-water blackout.
Description:
S.K.H. received support from a Royal Society Dorothy Hodgkin
fellowship; P.J.O.M. received support from a Royal
Society USA fellowship.
Keywords:
Marine mammal
;
Otariid
;
Diving
;
Physiology
;
Antarctic fur seal
;
Shallow-water blackout
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
756053 bytes
Format:
application/pdf
Permalink
