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 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.

Lead–radium dating of orange roughy (Hoplostethus atlanticus): validation of a centenarian life span

2009 ◽  
Vol 66 (7) ◽  
pp. 1130-1140 ◽  
Author(s):  
Allen H. Andrews ◽  
Dianne M. Tracey ◽  
Matthew R. Dunn
Keyword(s):  
Life Span ◽  
Age Groups ◽  
Growth Zone ◽  
Age Validation ◽  
Orange Roughy ◽  
Thin Sections ◽  
Lead 210 ◽  
High Degree ◽  
Hoplostethus Atlanticus ◽  
Age Estimates

Life-span estimates for orange roughy ( Hoplostethus atlanticus ) range from ~20 years to well over 100 years. In this study, an improved lead–radium dating technique provided independent age estimates from sagittal otoliths. This technique used the known properties of radioactivity for lead-210 and radium-226 to determine the validity of fish age estimates. An improvement to lead–radium dating using mass spectrometry allowed the use of smaller samples than previously possible; therefore, an application was made to otolith cores, the first few years of otolith growth. This approach circumvented the use of whole otoliths and alleviated many of the assumptions that were necessary in previous lead–radium dating applications. Hence, it was possible to critically evaluate lead–radium dating as a tool in fish age validation. The measurement of lead–radium ratios for a series of age groups that consisted of otolith cores, grouped based on growth-zone counts from thin sections, showed a high degree of correlation to the expected lead–radium ingrowth curve. This finding provided support for age estimation procedures using thin otolith sectioning. As independent estimates of age, the results indicated that fish in the oldest age group were at least 93 years old, providing robust support for a centenarian life span.

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.

scholarly journals Improved Hough Transform and Total Variation Algorithms for Features Extraction of Wood

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 466
Author(s):  
Weiwei Du ◽  
Yarui Xi ◽  
Kiichi Harada ◽  
Yumei Zhang ◽  
Keiko Nagashima ◽  
...  
Keyword(s):  
Total Variation ◽  
Hough Transform ◽  
Annual Ring ◽  
Wood Quality ◽  
Volume Density ◽  
Low Noise ◽  
Impact Factors ◽  
Annual Rings ◽  
New Model ◽  
Model Combining

Research shows that the intensity impact factors of wood, such as late timber ratio, volume density and the intensity of itself, correlate with the width of wood annual rings. Therefore, extracting wood annual ring information from wood images is helpful for evaluating wood quality. During the past few years, many researchers have conducted defect detection by studying the information of wood images. However, there are few in-depth studies on the statistics and calculation of wood annual ring information. This study proposes a new model combining the Total Variation (TV) algorithm and the improved Hough transform to accurately measure the wood annual ring information. The TV algorithm is used to suppress image noise, and the Hough transform is for detecting the center of the wood image. Moreover, the edges of wood annual rings are extracted, and the statistical ring information is calculated. The experimental results show that the new model has good denoising capability, clearly extract the edges of wood annual rings and calculate the related parameters from the indoor wood images of the processed logs and the unprocessed low-noise logs.

Seasonal Variation in Traumatic Resin Canal Formation in Chamaecyparis Obtusa Phloem

IAWA Journal ◽  
1998 ◽  
Vol 19 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Keiko Kuroda
Keyword(s):  
Annual Ring ◽  
Stem Canker ◽  
Chamaecyparis Obtusa ◽  
Resin Canal ◽  
Annual Rings ◽  
Secondary Phloem ◽  
Resinous Stem Canker ◽  
Traumatic Resin Canals ◽  
Resin Canals ◽  
Artificial Wounding

Trunks of Chamaecyparis obtusa were injured to examine seasonal differences in traumatic resin canal formation in secondary phloem. Even after wounding during winter, differentiation of axial parenchyma into epithelium was initiated, and vertical resin canals formed. After winter wounding, resin canal development was slower and the tangential extent of resin canals was narrower than after spring wounding, and it took one to two months until resin secretion began. After spring wounding, the sites of resin canal formation were the 1- and 2-year-old annual rings of phloem. In August, the location of resin canal formation shifted into the current and 1-year-old annual ring. Resin canals never formed in secondary phloem areas that were 3 or more years old. In C. obtusa trunks that are affected by the resinous stem canker, numerous tangentiallines of resin canals are found throughout the phloem, not just recent and 1- to 2-year-old phloem. The present research indicates that these many lines of resin canals were not formed at one time, and that the stimuli that induce traumatic resin canals must occur repeatedly over many years. The data on artificial wounding effects are useful for understanding resinous stem canker.

INTERVASCULAR PITTING ACROSS THE ANNUAL RING BOUNDARY IN BETULA PLATYPHYLLA VAR. JAPONICA AND FRAXINUS MANDSHURICA VAR. JAPONICA

IAWA Journal ◽  
2004 ◽  
Vol 25 (2) ◽  
pp. 129-140 ◽  
Author(s):  
Yuzou Sano
Keyword(s):  
Annual Ring ◽  
Peripheral Region ◽  
Betula Platyphylla ◽  
Annual Rings ◽  
Fraxinus Mandshurica ◽  
Common Wall ◽  
Pit Membrane ◽  
Perforation Plates ◽  
Soluble Material ◽  
Ring Boundary

The structure of intervascular pits, located at the boundary between the outermost and the second youngest annual rings in Betula platyphylla var. japonica and Fraxinus mandshurica var. japonica was examined by field-emission scanning electron microscopy. Unilaterally compound pits were present in the intervascular common wall at the annual ring boundary in both species. On the outer annual ring side of the unilaterally compound pits, outlines of pit membranes were curved or trifoliate, and each pit aperture was often elongated and curved. The porosity of the intervascular pit membranes differed between the two species. In B. platyphylla var. japonica, microfibrils were loosely packed in the peripheral region of each pit membrane, and openings of up to 300 nm in width were observed. By contrast, microfibrils were densely packed throughout the entire pit membranes in F. mandshurica var. japonica, and no openings perforating the pit membranes entirely were found. In addition, each species exhibited some unique features. In B. platyphylla var. japonica, extensive ethanol-soluble material was detected not only in the intervascular pits but also on scalariform perforation plates. In F. mandshurica var. japonica, we observed fine curly fibrils of unkown chemical composition in the intervascular pit membranes.

scholarly journals Cambridge University Natural Radiocarbon Measurements IV: Nuclear-Weapon Testing and the Atmospheric Radiocarbon Concentration

Radiocarbon ◽  
1961 ◽  
Vol 3 ◽  
pp. 77-80 ◽  
Author(s):  
H. Godwin ◽  
E. H. Willis
Keyword(s):  
Rapid Growth ◽  
Nuclear Weapon ◽  
Annual Ring ◽  
Populus Nigra ◽  
Annual Rings ◽  
Cambridge University ◽  
Annual Crops ◽  
Nuclear Weapon Testing ◽  
Weapon Testing

In continuance of investigations upon successive annual crops of oats reported in Radiocarbon Supplement, Volume 2, we undertook the analysis of successive annual rings of a tree that had been growing throughout the period covered by the oat-crop assays, namely 1953 to 1959. The selected tree was a straight-boled specimen of Populus nigra from the Forestry Commission's plantations at Santon Downham, near Thetford, Norfolk. It had been planted in 1929 and was felled on 21 October, 1959. Shortly afterwards, it was brought into the laboratory and sawn into slices just over 1 in. thick. The surfaces having been smoothed, the annual-ring contacts were marked, and within each annual ring the inner (spring) wood was marked off from the outer (autumn) wood. The tree had been chosen as one exhibiting rapid growth and it proved fairly easy to dissect off with a chisel all the separate half-rings between spring 1953 and the end of 1959. In the event, activities were determined only upon four of the half or whole rings.

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 Evidence of underestimation of European hake growth in the Bay of Biscay, and its relationship with bias in the agreed method of age estimation

2006 ◽  
Vol 63 (9) ◽  
pp. 1674-1681 ◽  
Author(s):  
Hélène de Pontual ◽  
Anne Laure Groison ◽  
Carmen Piñeiro ◽  
Michel Bertignac
Keyword(s):  
Age Estimation ◽  
Good Condition ◽  
Estimation Method ◽  
Somatic Growth ◽  
Biological Knowledge ◽  
Data Sets ◽  
Bay Of Biscay ◽  
Age Validation ◽  
Management Advice ◽  
European Hake

Abstract In 2002, a pilot experiment on hake tagging was carried out using methodology specifically developed to catch and handle fish in good condition. By the end of 2005, 36 hake and five tags had been returned to the laboratory (a 3.1% return rate) with a maximum time at liberty of 1066 days. The somatic growth of the recoveries proved to be twofold higher than that expected from published von Bertalanffy growth functions for the species in the Bay of Biscay. The growth underestimation was related to age overestimation, as demonstrated by two independent analyses. The first was based on a blind interpretation of marked otoliths conducted independently by two European experts involved in the routine age estimation of hake. The result shows that the age estimates were neither accurate (inconsistent with oxytetracycline mark positions) nor precise. The second approach compared the predicted otolith growth with the observed growth, and the discrepancy between the two data sets was large. Both types of analyses invalidate the internationally agreed age estimation method and demonstrate a need for further research. Although based on limited data, the study highlights the need to improve biological knowledge of the species in order to improve assessment and management advice. It also strengthens the argument for age validation.

scholarly journals Two sources of bias explain errors in facial age estimation

2018 ◽  
Vol 5 (10) ◽  
pp. 180841 ◽  
Author(s):  
Colin W. G. Clifford ◽  
Tamara L. Watson ◽  
David White
Keyword(s):  
Social Interactions ◽  
Age Estimation ◽  
Estimation Error ◽  
Age Groups ◽  
Large Database ◽  
Police Investigations ◽  
Immediate Experience ◽  
Improving Accuracy ◽  
Facial Age ◽  
Age Estimates

Accurate age estimates underpin our everyday social interactions, the provision of age-restricted services and police investigations. Previous work suggests that these judgements are error-prone, but the processes giving rise to these errors are not understood. Here, we present the first systematic test of bias in age estimation using a large database of standardized passport images of heterogeneous ages ( n = 3948). In three experiments, we tested a range of perceiver age groups ( n = 84), and found average age estimation error to be approximately 8 years. We show that this error can be attributed to two separable sources of bias. First, and accounting for the vast majority of variance, our results show an assimilative serial dependency whereby estimates are systematically biased towards the age of the preceding face. Second, younger faces are generally perceived to be older than they are, and older faces to be younger. In combination, these biases account for around 95% of variance in age estimates. We conclude that perception of age is modulated by representations that encode both a viewer's recent and normative exposure to faces. The finding that age perception is subject to strong top-down influences based on our immediate experience has implications for our understanding of perceptual processes involved in face perception, and for improving accuracy of age estimation in important real-world tasks.

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