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Underwater working times in two groups of traditional apnea divers in Asia: the Ama and the Bajau

Schagatay, Erika; Lodin-Sundstrom, Angelica and Abrahamsson, Erik LU (2011) In Diving and Hyperbaric Medicine 41(1). p.27-30
Abstract
(Schagatay E, Lodin-Sundstrom A. Abrahamsson E. Underwater working times in two groups of traditional apnea divers in Asia: the Ama and the Bajau. Diving and Hyperbaric Medicine. 2011;41(1):27-30.) Introduction: Traditional apnea diving for sea harvesting for a living continues in some communities in Asia, the outcome being dependent on the total underwater working time. We studied dive and surface interval durations and daily time spent submerged by Japanese Ama and the Phillipine Bajau. Methods: Diving and surface interval durations were timed, and daily in-water working time noted for 14 female Ama (mean age 60 years) during sea-mollusc collection, and five male Bajau divers (mean age 38 years) during spearfishing, using direct... (More)
(Schagatay E, Lodin-Sundstrom A. Abrahamsson E. Underwater working times in two groups of traditional apnea divers in Asia: the Ama and the Bajau. Diving and Hyperbaric Medicine. 2011;41(1):27-30.) Introduction: Traditional apnea diving for sea harvesting for a living continues in some communities in Asia, the outcome being dependent on the total underwater working time. We studied dive and surface interval durations and daily time spent submerged by Japanese Ama and the Phillipine Bajau. Methods: Diving and surface interval durations were timed, and daily in-water working time noted for 14 female Ama (mean age 60 years) during sea-mollusc collection, and five male Bajau divers (mean age 38 years) during spearfishing, using direct observations and depth-time recorders. Results: In the Ama, mean (SD) dive duration was 38 (8) s, with mean surface interval duration of 38 (8) s, at depths of 5-12 metres' sea water (msw), and diving constituted 50 (4)% of the total immersed working time, which was limited to 4 h per day by fishing regulations. In the Bajau, mean dive duration was 28 (9) s, with surface intervals of 19 (8) s, at depths of 5-7 msw, and diving was 60 (6)% of the total working time. Diving patterns in Hegura-Ama were similar to those previously reported, with up to 2 h per day spent under water. The Bajau total working time of 2-9 h per day suggests that some divers may spend more than 5 h per day submerged, which is the greatest daily apnea diving time reported in humans. Conclusions: We conclude that natural human diving ability in these two groups of traditional apnea divers allows efficient sea harvesting at shallow depths and that the outcome does not seem to be limited by total daily apnea time. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Breath-hold diving, freediving, spearfishing, performance, indigenous, divers, diving research
in
Diving and Hyperbaric Medicine
volume
41
issue
1
pages
27 - 30
publisher
South Pacific Underwater Med Soc
external identifiers
  • wos:000289180600007
  • scopus:79955795753
ISSN
1833-3516
language
English
LU publication?
yes
id
24e72ac5-7371-4ba1-989b-56db7476169a (old id 1925452)
date added to LUP
2011-05-12 15:18:12
date last changed
2017-07-09 04:08:06
@article{24e72ac5-7371-4ba1-989b-56db7476169a,
  abstract     = {(Schagatay E, Lodin-Sundstrom A. Abrahamsson E. Underwater working times in two groups of traditional apnea divers in Asia: the Ama and the Bajau. Diving and Hyperbaric Medicine. 2011;41(1):27-30.) Introduction: Traditional apnea diving for sea harvesting for a living continues in some communities in Asia, the outcome being dependent on the total underwater working time. We studied dive and surface interval durations and daily time spent submerged by Japanese Ama and the Phillipine Bajau. Methods: Diving and surface interval durations were timed, and daily in-water working time noted for 14 female Ama (mean age 60 years) during sea-mollusc collection, and five male Bajau divers (mean age 38 years) during spearfishing, using direct observations and depth-time recorders. Results: In the Ama, mean (SD) dive duration was 38 (8) s, with mean surface interval duration of 38 (8) s, at depths of 5-12 metres' sea water (msw), and diving constituted 50 (4)% of the total immersed working time, which was limited to 4 h per day by fishing regulations. In the Bajau, mean dive duration was 28 (9) s, with surface intervals of 19 (8) s, at depths of 5-7 msw, and diving was 60 (6)% of the total working time. Diving patterns in Hegura-Ama were similar to those previously reported, with up to 2 h per day spent under water. The Bajau total working time of 2-9 h per day suggests that some divers may spend more than 5 h per day submerged, which is the greatest daily apnea diving time reported in humans. Conclusions: We conclude that natural human diving ability in these two groups of traditional apnea divers allows efficient sea harvesting at shallow depths and that the outcome does not seem to be limited by total daily apnea time.},
  author       = {Schagatay, Erika and Lodin-Sundstrom, Angelica and Abrahamsson, Erik},
  issn         = {1833-3516},
  keyword      = {Breath-hold diving,freediving,spearfishing,performance,indigenous,divers,diving research},
  language     = {eng},
  number       = {1},
  pages        = {27--30},
  publisher    = {South Pacific Underwater Med Soc},
  series       = {Diving and Hyperbaric Medicine},
  title        = {Underwater working times in two groups of traditional apnea divers in Asia: the Ama and the Bajau},
  volume       = {41},
  year         = {2011},
}