Time in tortoiseshell: a bomb radiocarbon-validated chronology in sea turtle scutes

Van Houtan, Kyle S.; Andrews, Allen H.; Jones, T. Todd; Murakawa, Shawn K. K.; Hagemann, Molly E.

doi:10.1098/rspb.2015.2220

i

Time in tortoiseshell: a bomb radiocarbon-validated chronology in sea turtle scutes

2016
By Van Houtan, Kyle S. ; Andrews, Allen H. ; Jones, T. Todd ; ...

Details

Journal Title:

Proceedings of the Royal Society B: Biological Sciences
Personal Author:

Van Houtan, Kyle S. ; Andrews, Allen H. ; Jones, T. Todd ; Murakawa, Shawn K. K. ; Hagemann, Molly E.
NOAA Program & Office:

NMFS (National Marine Fisheries Service) ; PIFSC (Pacific Islands Fisheries Science Center) ; CoRIS (Coral Reef Information System)
Description:

Some of the most basic questions of sea turtle life history are also the most elusive. Many uncertainties surround lifespan, growth rates, maturity and spatial structure, yet these are critical factors in assessing population status. Here we examine the keratinized hard tissues of the hawksbill ( Eretmochelys imbricata ) carapace and use bomb radiocarbon dating to estimate growth and maturity. Scutes have an established dietary record, yet the large keratin deposits of hawksbills evoke a reliable chronology. We sectioned, polished and imaged posterior marginal scutes from 36 individual hawksbills representing all life stages, several Pacific populations and spanning eight decades. We counted the apparent growth lines, microsampled along growth contours and calibrated Δ 14 C values to reference coral series. We fit von Bertalanffy growth function (VBGF) models to the results, producing a range of age estimates for each turtle. We find Hawaii hawksbills deposit eight growth lines annually (range 5–14), with model ensembles producing a somatic growth parameter ( k ) of 0.13 (range 0.1–0.2) and first breeding at 29 years (range 23–36). Recent bomb radiocarbon values also suggest declining trophic status. Together, our results may reflect long-term changes in the benthic community structure of Hawaii reefs, and possibly shed light on the critical population status for Hawaii hawksbills.
Keywords:

General Agricultural And Biological Sciences General Biochemistry, Genetics And Molecular Biology General Environmental Science General Immunology And Microbiology General Medicine General Agricultural And Biological Sciences General Biochemistry, Genetics And Molecular Biology General Immunology And Microbiology General Agricultural And Biological Sciences General Biochemistry, Genetics And Molecular Biology General Immunology And Microbiology
Source:

Proceedings of the Royal Society B: Biological Sciences, 283(1822), 20152220
DOI:

https://doi.org/10.1098/rspb.2015.2220
ISSN:

0962-8452 ; 1471-2954
Format:

PDF
Publisher:

The Royal Society
Document Type:

Journal Article
Rights Information:

Other
Compliance:

Library
Main Document Checksum:

urn:sha256:17b2d835d2f38a325d4e8c3683ba47a9d3b180e3bd480032d54f5c1bf55c8498
Download URL:

https://repository.library.noaa.gov/view/noaa/54933/noaa_54933_DS1.pdf
File Type:

[PDF - 904.60 KB ]

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