Refined bomb radiocarbon dating of two iconic fishes of the Great Barrier Reef

2015 ◽  
Vol 66 (4) ◽  
pp. 305 ◽  
Author(s):  
Allen H. Andrews ◽  
John H. Choat ◽  
Richard J. Hamilton ◽  
Edward E. DeMartini
Keyword(s):  
Great Barrier Reef ◽  
Radiocarbon Dating ◽  
Growth Zone ◽  
Barrier Reef ◽  
Hermatypic Coral ◽  
Advanced Technologies ◽  
Bomb Radiocarbon ◽  
Growth Zones ◽  
Bolbometopon Muricatum ◽  
Age Estimates

Refinements to the methodology of bomb radiocarbon dating made it possible to validate age estimates of the humphead wrasse (Cheilinus undulatus) and bumphead parrotfish (Bolbometopon muricatum). Age for these species has been estimated from presumed annual growth zones in otoliths at ~30 and ~40 years respectively. The validity of these estimates was tested using bomb radiocarbon dating on the small and fragile otoliths of these species, and provided an opportunity to refine the method using advanced technologies. A regional Δ14C reference record from hermatypic coral cores from the Great Barrier Reef was assembled and Δ14C measurements from extracted otolith cores of adult otoliths were successful. Validated ages supported the accuracy of growth zone derived ages using sectioned sagittal otoliths.

Great longevity of speckled hind (Epinephelus drummondhayi), a deep-water grouper, with novel use of postbomb radiocarbon dating in the Gulf of Mexico

2013 ◽  
Vol 70 (8) ◽  
pp. 1131-1140 ◽  
Author(s):  
Allen H. Andrews ◽  
Beverly K. Barnett ◽  
Robert J. Allman ◽  
Ryan P. Moyer ◽  
Hannah D. Trowbridge
Keyword(s):  
Gulf Of Mexico ◽  
Deep Water ◽  
Radiocarbon Dating ◽  
Early Growth ◽  
Economic Importance ◽  
Growth Characteristics ◽  
Adult Age ◽  
Bomb Radiocarbon ◽  
Growth Zones ◽  
Age Estimates

Growth characteristics are poorly understood for speckled hind (Epinephelus drummondhayi), a tropical deep-water grouper of economic importance that is considered overfished. Age has been validated for early growth, but the validity of adult age estimates is unknown. A few studies of growth zones in otoliths have revealed maximum age estimates of 15–35 years, which have been uncritically assumed as longevity. To answer questions about adult age, bomb radiocarbon dating was used to provide validated age estimates. A novel aspect of this study was use of the postbomb radiocarbon decline period (ca. 1980–2004) to age younger fish, an approach that was validated with known-age otoliths. Bomb radiocarbon dating provided valid length-at-age estimates ranging from ∼5 years to more than 45 years. Age was unexpectedly greater than previous estimates for more than half the fish used in this study, and longevity may approach 60–80 years. This study extends the utility of bomb radiocarbon dating by more than 20 years and adds to the growing perspective that deep-water tropical fishes can be long-lived.

scholarly journals Bomb radiocarbon dating of three important reef-fish species using Indo-Pacific Δ14C chronologies

2011 ◽  
Vol 62 (11) ◽  
pp. 1259 ◽  
Author(s):  
Allen H. Andrews ◽  
John M. Kalish ◽  
Stephen J. Newman ◽  
Justine M. Johnston
Keyword(s):  
Fish Species ◽  
Age Estimation ◽  
Radiocarbon Dating ◽  
Reef Fishes ◽  
Growth Zone ◽  
Age And Growth ◽  
Thin Sections ◽  
Bomb Radiocarbon ◽  
Reef Fish Species ◽  
Age Estimates

Demersal reef fishes of the Indo-Pacific are under increasing pressure as a fisheries resource, yet many of the important life history characteristics required for suitable management are poorly known. The three fish species, eightbar grouper (Hyporthodus octofasciatus), ruby snapper (Etelis carbunculus) and the spangled emperor (Lethrinus nebulosus), are important components of fisheries and ecosystems throughout the Indo-Pacific. Despite their importance, age and growth information is incomplete. Age has been estimated for E. carbunculus and L. nebulosus, but validated age beyond the first few years is lacking and for H. octofasciatus no age estimates exist. Bomb radiocarbon dating can provide age estimates that are independent of growth-zone counting, but only if appropriate reference Δ14C chronologies exist. In this study, a series of Δ14C records from hermatypic corals was assembled to provide a basis for bomb radiocarbon dating in the western Indo-Pacific region. Results provided (1) valid age estimates for comparison to age estimates from two facilities investigating growth-zones in otolith thin sections; (2) support for age estimation protocols using otolith thin sections; and (3) the information necessary for further refinement of age estimation procedures. Estimates of longevity from bomb radiocarbon dating agree with some prior studies: H. octofasciatus, E. carbunculus and L. nebulosus all being long-lived species with life spans of at least 43, 35 and 28 years respectively.

Radiocarbon ages from the northern Great Barrier Reef

1978 ◽  
Vol 291 (1378) ◽  
pp. 139-158 ◽  
Keyword(s):  
Great Barrier Reef ◽  
Sea Level ◽  
Time Scale ◽  
Radiocarbon Dating ◽  
Barrier Reef ◽  
Laboratory Methods ◽  
Reef Environments ◽  
History Of ◽  
Reef Islands ◽  
Radiometric Ages

The aims of the 1973 Great Barrier Reef Expedition’s radiocarbon dating programmes were: (i) to collect live specimens from various reef environments to serve as modern reference standards; (ii) to evaluate the suitability of materials from the drilling, geomorphic and sediment programmes for dating purposes; and (iii) to date appropriate samples related to those programmes. The radiometric ages provide a time scale for the evolution of reefs and reef islands, and the history of sea level in the area. The purpose of this paper is to report results of all ages determined to date, to describe field and laboratory methods used and to assess the reliability of the ages in terms of (i) the actual materials dated and (ii) the geomorphic, ecological or stratigraphic units from which the samples were obtained. Seventy-nine determinations based on 74 samples are reported. No interpretation of the results is attempted here.

Age validation of yellowfin (Thunnus albacares) and bigeye (Thunnus obesus) tuna of the northwestern Atlantic Ocean

2020 ◽  
Vol 77 (4) ◽  
pp. 637-643 ◽  
Author(s):  
Allen H. Andrews ◽  
Ashley Pacicco ◽  
Robert Allman ◽  
Brett J. Falterman ◽  
Erik T. Lang ◽  
...  
Keyword(s):  
Growth Zone ◽  
Yellowfin Tuna ◽  
Age And Growth ◽  
Thunnus Albacares ◽  
Bigeye Tuna ◽  
Age Validation ◽  
Thunnus Obesus ◽  
Bomb Radiocarbon ◽  
Age Estimates ◽  
Age Reading

Estimates of age and growth of yellowfin (Thunnus albacares) and bigeye (Thunnus obesus) tuna remain problematic because validation of growth zone deposition (opaque and translucent) has not been properly evaluated. Otolith growth structure (zone clarity) can be poorly defined for tropical tunas, but the use of bomb radiocarbon dating has validated age estimates to 16–18 years for yellowfin and bigeye tuna. Use of the radiocarbon decline period — defined by regional coral and otoliths — provided valid ages through ontogeny. Yellowfin tuna aged 2–18 years (n = 34, 1029–1810 mm FL) and bigeye tuna aged 3–17 years (n = 12, 1280–1750 mm FL) led to birth years that were coincident with the bomb radiocarbon decline. The results indicate there was no age reading bias for yellowfin tuna and that age estimates of previous studies were likely underestimated for both species.

scholarly journals ANU Radiocarbon Date List VIII

Radiocarbon ◽  
1981 ◽  
Vol 23 (1) ◽  
pp. 1-13 ◽  
Author(s):  
H A Polach ◽  
R F McLean ◽  
B G Thom ◽  
D R Stoddart ◽  
David Hopley ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Sea Level ◽  
Time Scale ◽  
Radiocarbon Dating ◽  
Radiocarbon Date ◽  
Barrier Reef ◽  
Reef Environments ◽  
History Of ◽  
Reef Islands ◽  
Radiometric Ages

The aims of the 1973 Great Barrier Reef Expedition's radiocarbon dating programs were: 1) to collect live specimens from various reef environments to serve as modern reference standards, 2) to evaluate suitability of materials from drilling, geomorphic, and sediment programs for dating purposes, and 3) to date appropriate samples related to those programs. Radiometric ages provide a time scale for evolution of reefs and reef islands, and the history of sea level in the area.

Taphonomic bias and time-averaging in tropical molluscan death assemblages: differential shell half-lives in Great Barrier Reef sediment

Paleobiology ◽  
2009 ◽  
Vol 35 (4) ◽  
pp. 565-586 ◽  
Author(s):  
Matthew A. Kosnik ◽  
Quan Hua ◽  
Darrell S. Kaufman ◽  
Raphael A. Wüst
Keyword(s):  
Great Barrier Reef ◽  
Time Averaging ◽  
Burial Depth ◽  
Barrier Reef ◽  
Amino Acid Racemization ◽  
Sedimentary Environments ◽  
Depositional Setting ◽  
Lagoonal Sediment ◽  
Water Carbonate ◽  
Age Estimates

Radiocarbon-calibrated amino acid racemization ages of 428 individually dated shells representing four molluscan taxa are used to quantify time-averaging and shell half-lives with increasing burial depth in the shallow-water carbonate lagoon of Rib Reef, central Great Barrier Reef, Australia. The top 20 cm of sediment contains a distinct, essentially modern assemblage. Shells recovered at depths from 25 to 125 cm are age-homogeneous and significantly older than the surface layer. Taxon age distributions within sedimentary layers indicate that the top 125 cm of lagoonal sediment is thoroughly mixed on a sub-century scale. The age distributions and shell half-lives of four taxa (Ethalia, Natica, Tellina, and Turbo) are found to be largely distinct. Shell half-lives do not coincide with any single morphological characteristic thought to infer greater durability, but they are strongly related to a combined durability score based on shell density, thickness, and shape. These results illustrate the importance of bioturbation in tropical sedimentary environments, indicate that age estimates in this depositional setting are sensitive to taxon choice, and quantify a taxon-dependent bias in shell longevity and death assemblage formation.

scholarly journals Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating

2007 ◽  
Vol 58 (6) ◽  
pp. 531 ◽  
Author(s):  
Allen H. Andrews ◽  
Lisa A. Kerr ◽  
Gregor M. Cailliet ◽  
Thomas A. Brown ◽  
Craig C. Lundstrom ◽  
...  
Keyword(s):  
Age Estimation ◽  
Age Validation ◽  
14C Dating ◽  
Age Composition ◽  
Bomb Radiocarbon ◽  
Estimation Procedures ◽  
Limited Application ◽  
Growth Zones ◽  
Minimum Estimate ◽  
Age Estimates

Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from south-east Alaska to southern California, but localised stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from ~20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep-dwelling and may be long-lived. In this study, the unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon (14C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining that a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to ~50–60 years. These findings were further supported by Δ14C data, which indicated that a minimum estimate of lifespan was 44 ± 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.

Bomb radiocarbon and lead - radium disequilibria in otoliths of bocaccio rockfish (Sebastes paucispinis): a determination of age and longevity for a difficult-to-age fish

2005 ◽  
Vol 56 (5) ◽  
pp. 517 ◽  
Author(s):  
Allen H. Andrews ◽  
Erica J. Burton ◽  
Lisa A. Kerr ◽  
Gregor M. Cailliet ◽  
Kenneth H. Coale ◽  
...  
Keyword(s):  
Time Series ◽  
Growth Zone ◽  
Reference Time ◽  
Bomb Radiocarbon ◽  
Age Estimates

Longevity estimates for the bocaccio rockfish (Sebastes paucispinis) using traditional techniques range from less than 20 years to approximately 50 years. Otoliths of bocaccio are difficult to age, and previous attempts to validate ages have been unsuccessful. Because otolith age suggests the bocaccio are reasonably long-lived, lead–radium dating was used in an attempt to independently age bocaccio otoliths. The measured 210Pb and 226Ra activities were among the lowest reported and resulted in poor radiometric age resolution; however, the break-and-burn technique clearly underestimated age in some cases with the longevity of the bocaccio being at least 31 years. To provide better age resolution, the bomb radiocarbon approach was applied to individual otoliths. Based on measured radiocarbon levels relative to a reference time-series, several specimens were aged at approximately 30–40 years. To evaluate these determinations, the remaining otolith of the pair was sectioned and aged blind. The result was an excellent fit to the reference time-series and a validation of the age estimates. The maximum age from growth zone counts was 37 ± 2 years, which is consistent with a reported maximum age of approximately 50 years.

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