Satellite tracking reveals unusual diving characteristics for a marine reptile, the olive ridley turtle Lepidochelys olivacea

Clive McMahon, Corey Bradshaw, Graeme Hays

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    The movements, diving behaviour and thermal environment occupied by 4 adult female olive ridley turtles Lepidochelys olivacea in northern Australia were determined through satellite telemetry. Patterns of behaviour recorded were rather unusual compared to other sea turtles in that dives were mainly deep, largely benthic and exceptionally long (>2 h) in some cases, characteristics typical of over-wintering turtles in colder environments. One individual occupied shallow coastal foraging zones, while the others foraged far from land (probably on the seabed) in relatively deep water (>100 m). Individuals performed long dives (frequently >100 min), but from the short post-dive intervals we suggest that these dives were mainly aerobic. Maximum dive depth recorded was 200 � 20 m (mean maximum depths ranged from 20.1 to 46.7 m across individuals; n = 17328 dives in total; depths ?3 m were considered 'dives') and the maximum duration was 200 � 20 min (mean durations ranged from 24.5 to 48.0 min across individuals). Temperature profiles indicate that turtles experienced temperatures ranging from 23 to 29�C at the surface, with the lowest temperature recorded (18.7�C) at a depth of 98 m. Only 6.9% of the dives were in water <20�C. From time-allocation at depth (TAD) scores, we demonstrated that many dives reaching the known or inferred sea bottom were U-shaped, but there was no apparent diel signal in dive depth. This suggests that many benthic dives were not associated exclusively with resting behaviour and likely had a foraging component as well. The ability to perform long benthic dives allows this species to exploit deeper benthic environments in addition to the shallow coastal areas more generally occupied by adult hard-shelled sea turtles (e.g. green and hawksbill turtles). Deep benthic dives also occur in certain marine mammals (e.g. narwhals) and sea birds (e.g. rockhopper penguins) and therefore seem to be a general foraging strategy exploited by animals that can perform long dives. � Inter-Research 2007.
    Original languageEnglish
    Pages (from-to)239-252
    Number of pages14
    JournalMarine Ecology - Progress Series
    Volume329
    Publication statusPublished - 2007

    Fingerprint

    diving
    reptile
    turtle
    reptiles
    sea turtles
    foraging
    turtles
    Eretmochelys imbricata
    time allocation
    diving behavior
    benthic environment
    benthic zone
    Chelonia mydas
    duration
    marine mammal
    marine mammals
    penguins
    telemetry
    seabird
    seabirds

    Cite this

    @article{d6b84455a7864d87807ef0fba140cf6c,
    title = "Satellite tracking reveals unusual diving characteristics for a marine reptile, the olive ridley turtle Lepidochelys olivacea",
    abstract = "The movements, diving behaviour and thermal environment occupied by 4 adult female olive ridley turtles Lepidochelys olivacea in northern Australia were determined through satellite telemetry. Patterns of behaviour recorded were rather unusual compared to other sea turtles in that dives were mainly deep, largely benthic and exceptionally long (>2 h) in some cases, characteristics typical of over-wintering turtles in colder environments. One individual occupied shallow coastal foraging zones, while the others foraged far from land (probably on the seabed) in relatively deep water (>100 m). Individuals performed long dives (frequently >100 min), but from the short post-dive intervals we suggest that these dives were mainly aerobic. Maximum dive depth recorded was 200 � 20 m (mean maximum depths ranged from 20.1 to 46.7 m across individuals; n = 17328 dives in total; depths ?3 m were considered 'dives') and the maximum duration was 200 � 20 min (mean durations ranged from 24.5 to 48.0 min across individuals). Temperature profiles indicate that turtles experienced temperatures ranging from 23 to 29�C at the surface, with the lowest temperature recorded (18.7�C) at a depth of 98 m. Only 6.9{\%} of the dives were in water <20�C. From time-allocation at depth (TAD) scores, we demonstrated that many dives reaching the known or inferred sea bottom were U-shaped, but there was no apparent diel signal in dive depth. This suggests that many benthic dives were not associated exclusively with resting behaviour and likely had a foraging component as well. The ability to perform long benthic dives allows this species to exploit deeper benthic environments in addition to the shallow coastal areas more generally occupied by adult hard-shelled sea turtles (e.g. green and hawksbill turtles). Deep benthic dives also occur in certain marine mammals (e.g. narwhals) and sea birds (e.g. rockhopper penguins) and therefore seem to be a general foraging strategy exploited by animals that can perform long dives. � Inter-Research 2007.",
    keywords = "benthic environment, benthivory, diving behavior, foraging behavior, habitat selection, metabolism, movement, oxic conditions, radiotelemetry, satellite data, temperature profile, turtle, Australasia, Australia, Animalia, Aves, Cheloniidae, Eretmochelys imbricata, Lepidochelys olivacea, Mammalia, Monodon, Reptilia, Spheniscidae, Testudines",
    author = "Clive McMahon and Corey Bradshaw and Graeme Hays",
    year = "2007",
    language = "English",
    volume = "329",
    pages = "239--252",
    journal = "Marine Ecology - Progress Series",
    issn = "0171-8630",
    publisher = "Inter-Research",

    }

    Satellite tracking reveals unusual diving characteristics for a marine reptile, the olive ridley turtle Lepidochelys olivacea. / McMahon, Clive; Bradshaw, Corey; Hays, Graeme.

    In: Marine Ecology - Progress Series, Vol. 329, 2007, p. 239-252.

    Research output: Contribution to journalArticleResearchpeer-review

    TY - JOUR

    T1 - Satellite tracking reveals unusual diving characteristics for a marine reptile, the olive ridley turtle Lepidochelys olivacea

    AU - McMahon, Clive

    AU - Bradshaw, Corey

    AU - Hays, Graeme

    PY - 2007

    Y1 - 2007

    N2 - The movements, diving behaviour and thermal environment occupied by 4 adult female olive ridley turtles Lepidochelys olivacea in northern Australia were determined through satellite telemetry. Patterns of behaviour recorded were rather unusual compared to other sea turtles in that dives were mainly deep, largely benthic and exceptionally long (>2 h) in some cases, characteristics typical of over-wintering turtles in colder environments. One individual occupied shallow coastal foraging zones, while the others foraged far from land (probably on the seabed) in relatively deep water (>100 m). Individuals performed long dives (frequently >100 min), but from the short post-dive intervals we suggest that these dives were mainly aerobic. Maximum dive depth recorded was 200 � 20 m (mean maximum depths ranged from 20.1 to 46.7 m across individuals; n = 17328 dives in total; depths ?3 m were considered 'dives') and the maximum duration was 200 � 20 min (mean durations ranged from 24.5 to 48.0 min across individuals). Temperature profiles indicate that turtles experienced temperatures ranging from 23 to 29�C at the surface, with the lowest temperature recorded (18.7�C) at a depth of 98 m. Only 6.9% of the dives were in water <20�C. From time-allocation at depth (TAD) scores, we demonstrated that many dives reaching the known or inferred sea bottom were U-shaped, but there was no apparent diel signal in dive depth. This suggests that many benthic dives were not associated exclusively with resting behaviour and likely had a foraging component as well. The ability to perform long benthic dives allows this species to exploit deeper benthic environments in addition to the shallow coastal areas more generally occupied by adult hard-shelled sea turtles (e.g. green and hawksbill turtles). Deep benthic dives also occur in certain marine mammals (e.g. narwhals) and sea birds (e.g. rockhopper penguins) and therefore seem to be a general foraging strategy exploited by animals that can perform long dives. � Inter-Research 2007.

    AB - The movements, diving behaviour and thermal environment occupied by 4 adult female olive ridley turtles Lepidochelys olivacea in northern Australia were determined through satellite telemetry. Patterns of behaviour recorded were rather unusual compared to other sea turtles in that dives were mainly deep, largely benthic and exceptionally long (>2 h) in some cases, characteristics typical of over-wintering turtles in colder environments. One individual occupied shallow coastal foraging zones, while the others foraged far from land (probably on the seabed) in relatively deep water (>100 m). Individuals performed long dives (frequently >100 min), but from the short post-dive intervals we suggest that these dives were mainly aerobic. Maximum dive depth recorded was 200 � 20 m (mean maximum depths ranged from 20.1 to 46.7 m across individuals; n = 17328 dives in total; depths ?3 m were considered 'dives') and the maximum duration was 200 � 20 min (mean durations ranged from 24.5 to 48.0 min across individuals). Temperature profiles indicate that turtles experienced temperatures ranging from 23 to 29�C at the surface, with the lowest temperature recorded (18.7�C) at a depth of 98 m. Only 6.9% of the dives were in water <20�C. From time-allocation at depth (TAD) scores, we demonstrated that many dives reaching the known or inferred sea bottom were U-shaped, but there was no apparent diel signal in dive depth. This suggests that many benthic dives were not associated exclusively with resting behaviour and likely had a foraging component as well. The ability to perform long benthic dives allows this species to exploit deeper benthic environments in addition to the shallow coastal areas more generally occupied by adult hard-shelled sea turtles (e.g. green and hawksbill turtles). Deep benthic dives also occur in certain marine mammals (e.g. narwhals) and sea birds (e.g. rockhopper penguins) and therefore seem to be a general foraging strategy exploited by animals that can perform long dives. � Inter-Research 2007.

    KW - benthic environment

    KW - benthivory

    KW - diving behavior

    KW - foraging behavior

    KW - habitat selection

    KW - metabolism

    KW - movement

    KW - oxic conditions

    KW - radiotelemetry

    KW - satellite data

    KW - temperature profile

    KW - turtle

    KW - Australasia

    KW - Australia

    KW - Animalia

    KW - Aves

    KW - Cheloniidae

    KW - Eretmochelys imbricata

    KW - Lepidochelys olivacea

    KW - Mammalia

    KW - Monodon

    KW - Reptilia

    KW - Spheniscidae

    KW - Testudines

    M3 - Article

    VL - 329

    SP - 239

    EP - 252

    JO - Marine Ecology - Progress Series

    JF - Marine Ecology - Progress Series

    SN - 0171-8630

    ER -