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.

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.

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.

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.

Bomb radiocarbon dating calibrates beluga (Delphinapterus leucas) age estimates

2006 ◽  
Vol 84 (12) ◽  
pp. 1840-1852 ◽  
Author(s):  
R.E.A. Stewart ◽  
S.E. Campana ◽  
C.M. Jones ◽  
B.E. Stewart
Keyword(s):  
Atomic Bomb ◽  
Growth Increment ◽  
Delphinapterus Leucas ◽  
Age Validation ◽  
Bomb Radiocarbon ◽  
Beluga Whale Delphinapterus Leucas ◽  
Layer Groups ◽  
Free Ranging ◽  
Accurate Indicator ◽  
Age Estimates

The ages of many mammals are estimated by counting growth layers in tooth sections, yet validation of age estimation techniques using free-ranging mammals has been problematic. Contrary to age estimates for most other animals in which it is assumed that one bipartite growth increment forms annually, beluga whale ( Delphinapterus leucas (Pallas, 1776)) age estimates have been calculated assuming that two growth layer groups (GLGs) form each year. Here we report the age validation for belugas based on date-specific incorporation of atomic bomb radiocarbon into tooth GLGs. Radiocarbon assays of dentinal layers formed in belugas harvested between 1895 and 2001 indicated that radiocarbon from atmospheric testing of nuclear weapons was incorporated into growing teeth and retained for the remaining life of the animal. Comparison of age determined by bomb radiocarbon with age determined by GLG counts indicated that GLGs form annually, not semiannually, and provide an accurate indicator of age for belugas up to at least 60 years old. Radiocarbon signatures of belugas were temporally and metabolically stable and were apparently derived more from the radiocarbon content of their prey than from water. Our understanding of many facets of beluga population dynamics is altered by the finding that this species lives twice as long as previously thought.

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.

Ageing of Adult Snapper (Pagrus auratus) from Otolith annual ring counts: Validation by tagging and Oxytetracycline Injection

1992 ◽  
Vol 43 (5) ◽  
pp. 1069 ◽  
Author(s):  
RICC Francis ◽  
LJ Paul ◽  
KP Mulligan
Keyword(s):  
Age Estimation ◽  
Growth Analysis ◽  
Annual Ring ◽  
Relative Strength ◽  
Error Rates ◽  
Annual Rings ◽  
Age Validation ◽  
Thin Sections ◽  
Pagrus Auratus ◽  
Age Estimates

Of 4657 snapper (Pagrus auratus) that were tagged, injected with oxytetracycline (OTC), and released in 1986-87, 1113 fish were recaptured after periods at liberty from 18 days to 3 years. An OTC mark was clearly visible in thin sections of all but four of a sample of 125 otoliths. In 90% of the remaining 121 otoliths the position of the OTC mark was correctly inferred from age readings (made without seeing the OTC mark) based on annual ring counts in otolith sections. It is concluded that the otolith rings are deposited annually, and estimates are made of error rates in age estimation-both in identifying annual rings and in interpreting the otolith edge. Further support for the ageing method is contributed by an analysis of the growth of tagged fish, and by year-to-year consistency in the relative strength of cohorts. The growth analysis showed a large (more than twofold) interyear variation in growth rates. Snapper (and other sparid) age estimates based on scale readings may be underestimates. It is recommended that age validation studies clearly distinguish between three separate factors: periodicity of marks, identification of marks, and edge interpretation.

scholarly journals Eye lens Δ14C validates otolith-derived age estimates of Gulf of Mexico reef fishes

2021 ◽  
Vol 78 (1) ◽  
pp. 13-17
Author(s):  
William F. Patterson ◽  
Beverly K. Barnett ◽  
Thomas C. TinHan ◽  
Susan K. Lowerre-Barbieri
Keyword(s):  
Reef Fishes ◽  
Eye Lens ◽  
Lens Protein ◽  
Lutjanus Campechanus ◽  
Age Validation ◽  
Bomb Radiocarbon ◽  
Reef Fish Species ◽  
Eye Lens Protein ◽  
The Relationship ◽  
Age Estimates

We tested whether Δ14C values of eye lens protein (crystallin) formed in early life could be utilized to validate marine bony fish age estimates via the bomb radiocarbon chronometer. The slope of the relationship between red snapper (Lutjanus campechanus; n = 8; 0 to 27 years old), otolith and eye lens core Δ14C values was not significantly different than 1, which was also true for seven additional reef fish species (n = 21; 0 to 24 years old). Results demonstrate eye lens core Δ14C can be utilized to validate age estimates of marine fishes, which will be useful in numerous age validation applications.

scholarly journals Linear decline in red snapper (Lutjanus campechanus) otolith Δ14C extends the utility of the bomb radiocarbon chronometer for fish age validation in the Northern Gulf of Mexico

2018 ◽  
Vol 75 (5) ◽  
pp. 1664-1671 ◽  
Author(s):  
Beverly K Barnett ◽  
Laura Thornton ◽  
Robert Allman ◽  
Jeffrey P Chanton ◽  
William F Patterson
Keyword(s):  
Gulf Of Mexico ◽  
Red Snapper ◽  
Lutjanus Campechanus ◽  
Age Validation ◽  
Data Set ◽  
Northern Gulf Of Mexico ◽  
Significant Difference ◽  
Bomb Radiocarbon ◽  
Relationship Of ◽  
Age Estimates

Abstract Radiocarbon (Δ14C) was analyzed in northern Gulf of Mexico (nGOM) red snapper (Lutjanus campechanus) otolith cores (n = 23), otolith edge samples (n = 12), and whole age-0 otoliths (n = 9), with edge samples and whole age-0 otoliths constituting known-age samples. There was no significant difference in the linear relationship of Δ14C versus year of formation between regional corals and known-age otolith samples, and a linear regression fit to the combined data from 1980 to 2015 extends the utility of the bomb radiocarbon chronometer for age validation. The entire regional coral and known-age otolith data set (1940 to 2015) was then utilized as a reference series to validate otolith-derived red snapper age estimates for cored otolith samples. A loess regression was fit to the reference data and then the sum of squared residuals (SSR) was computed from predicted versus observed birth years for cored adult otolith samples. This process was then repeated for ages biased ±1–4 years. Ages with no bias applied had the lowest SSR, thus validating red snapper age estimates and demonstrating the utility of the combined regional coral and known-age red snapper otolith Δ14C time series for age validation of nGOM marine fishes.

Mortality Estimation: Biased Results from Unbiased Ages

1984 ◽  
Vol 41 (12) ◽  
pp. 1843-1847 ◽  
Author(s):  
Jay Barlow
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Age Estimation ◽  
Age Determination ◽  
Mortality Rates ◽  
Age Classes ◽  
Estimation Errors ◽  
Mortality Estimation ◽  
Age Estimates

Estimates of mortality rates from age distributions are biased by imprecision in age estimation, even if age estimates are unbiased. I have derived a method for predicting the magnitude of this bias from information on the precision of age determination. Monte Carlo simulations show that bias can be accurately predicted. The commonly used Chapman–Robson mortality estimator is shown to be robust to imprecision in age determination if all age-classes are included. Errors are likely, however, if one or more age-classes are excluded or if other mortality estimators are used. Biases can be corrected if the distribution of age-estimation errors is known.

scholarly journals Bomb dating, age validation and quality control of age determinations of monodontids and other marine mammals

2014 ◽  
Vol 8 ◽  
Author(s):  
Steven E Campana ◽  
Robert EA Stewart
Keyword(s):  
Quality Control ◽  
Marine Mammals ◽  
Age Determination ◽  
Age Validation ◽  
Age Bias ◽  
Bomb Radiocarbon ◽  
Control Protocols ◽  
The 1960S ◽  
Age Determinations

Methods for confirming the accuracy of age determination methods are reasonably well established in fishes, but the millions of routine age determinations which take place every year require their own quality control protocols. In contrast, methods for ensuring accuracy in age determination of monodontids and other marine mammals are still being developed. Here we review the basis and application of bomb radiocarbon to marine mammal age validation, highlighting its value for providing unambiguous estimates of age for belugas and other long-lived animals which form growth bands. Bomb radiocarbon is particularly useful for marine mammals, given that the age of an individual animal can be determined to within ±1-3 years, as long as it was alive during the 1960s. However, ongoing age determinations require careful monitoring to ensure that age interpretations remain consistent across ages and through time. Quality control protocols using reference collections of ageing material, in conjunction with age bias plots and measures of precision, are capable of detecting virtually all of the systematic ageing errors that often occur once age determinations of an animal become routine.

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