@article {295,
	title = {Age Validation of Freshwater Drum using Bomb Radiocarbon},
	journal = {Transactions of the American Fisheries Society},
	volume = {138},
	year = {2009},
	note = {id: 802; 477EI Times Cited:1 Cited References Count:58Y},
	pages = {385-396},
	abstract = {The ages of freshwater drum Aplodinotus grunniens have typically been estimated by counting the growth increments on their scales or otoliths, but the accuracy of these estimates has not been validated. We used accelerator mass spectrometry (AMS) bomb radiocarbon dating to validate age estimates from sagittal otoliths of freshwater drum from the Lake Winnebago system, Wisconsin. The freshwater drum Delta C-14 chronology from the AMS assay closely reflects the timing and shape of other bomb radiocarbon chronologies, thus validating the accuracy of otolith growth increments to at least age 52 +/- 2 years. The progression of a strong 1983 year-class, which was detected every year sampled over the course of the study (1986, 2003-2007), and indices of year-class abundance calculated from trawling assessments on Lake Winnebago (1986-2007) corroborated otolith ages. Age estimate comparisons between scales, anal spines, dorsal spines, and otoliths showed scales and spines to be completely unreliable as aging structures after age 2. Freshwater drum live to very old ages relative to most other Great Lakes fishes; our oldest specimen based on an otolith age estimate was 58 years old.},
	issn = {0002-8487},
	doi = {10.1577/T08-097.1},
	author = {Davis-Foust, S. L. and Bruch, R. M. and Campana, S. E. and Olynyk, R. P. and Janssen, J.}
}
@article {350,
	title = {Bomb dating and age determination of skates (family Rajidae) off the eastern coast of Canada},
	journal = {Ices Journal of Marine Science},
	volume = {66},
	year = {2009},
	note = {id: 1856; 421XR Times Cited:3 Cited References Count:82Y},
	pages = {546-560},
	abstract = {Recent declines in abundance of skates off the eastern coast of Canada have heightened the need for validated age and growth estimates in the region. In all, 502 winter (Leucoraja ocellata), little (Leucoraja erinacea), thorny (Amblyraja radiata), and smooth (Malacoraja senta) skate vertebral centra collected seasonally between 1999 and 2004 were sectioned using a mass processing method, then used to reconstruct growth in each species. Bomb rediocarbon (Delta C-14) analysis was used to provide evidence of annual band-pair deposition in thorny skates. Estimates of L-infinity from traditional von Bertalanffy growth models (VBGM) ranged from 60.6 cm (little skate) to 89.7 cm (thorny skate), and K estimates from 0.07 (thorny skate) to 0.19 (little skate). A modified two-parameter VBGM (L-MAX = 94.1 cm) fitted to winter skate lenght-at-age data yielded a value of K to 0.15. Maximum observed ages ranged from 12 (little skate) to 19 years in both winter and thorny skates. The year-specific incorporation of Delta C-14 milled from thorny and winter skate vertebral sections closely resembled shark-derived reference chronology values from the Northwest Atlantic. Pre-bomb Delta C-14 in a thorny skate collected in 1988 and aged at 23 years appeared to validate age interpretations and suggested that thorny skate reach an absolute age of at least 28 years, the oldest validated age reported for any species of batoid.},
	issn = {1054-3139},
	doi = {10.1093/icesjms/fsp002},
	author = {McPhie, R. P. and Campana, S. E.}
}
@article {530,
	title = {Growth and sexual maturity of the northern propellerclam (Cyrtodaria siliqua) in Eastern Canada, with bomb radiocarbon age validation},
	journal = {Marine Biology},
	volume = {156},
	year = {2009},
	note = {id: 803; 413YA Times Cited:0 Cited References Count:45Y},
	pages = {1029-1037},
	abstract = {The northern propellerclam Cyrtodaria siliqua is a common bycatch in the Arctic surfclam, Mactromeris polynyma fishery on Banquereau Bank in Eastern Canada. Samples of the propellerclam from this exploited fishery were used to determine the life history characteristics of the population. The age structure of the population is dominated by old animals to ages exceeding 100 years. We validated the age estimates for the propellerclam through analysis of bomb-produced radiocarbon in the shell growth increments deposited before, during and after the atmospheric atomic bomb testing periods of the 1950s and 1960s. Radiocarbon from shells with presumed birth dates between the late 1950s and 1970s clearly reflected the sharp increase in oceanic radiocarbon attributable to previous nuclear testing, indicating that age estimates based on shell increment counts are accurate. Estimates of von Bertalanffy growth parameters revealed that the growth rate of the population was relatively rapid for the first 20 years of life, slowing down to very low growth rates thereafter. Sexual maturity was estimated as being reached at 28.6 mm in length and 4.7 years in age. Size-weight morphometric relationships were also calculated.},
	issn = {0025-3162},
	doi = {10.1007/s00227-009-1146-9},
	author = {Kilada, R. W. and Campana, S. E. and Roddick, D.}
}
@article {294,
	title = {Lake Sturgeon Age Validation using Bomb Radiocarbon and Known-Age Fish},
	journal = {Transactions of the American Fisheries Society},
	volume = {138},
	year = {2009},
	note = {id: 1855; 477EI Times Cited:1 Cited References Count:33Y},
	pages = {361-372},
	abstract = {Pectoral fin spines have been the accepted structure for estimating the age of various sturgeon species for nearly 100 years, though other structures have also been used (otoliths, pectoral girdle, scutes, and caudal fulcra). Accuracy of age estimates using any of these structures has not been validated, so we report the first use of bomb radiocarbon (C-14) assays to assess the validity of ages estimated using growth increments on pectoral fin spine and otolith frontal cross sections from lake sturgeon Acipenser fulvescens: we also assessed age estimates from pectoral fin spines of known-age lake sturgeon. Growth increments on pectoral fin spine cross sections underestimated true age of fish older than 14 years and error increased with age, whereas otoliths accurately estimated true age up to at least 52 years. Increment formation on pectoral fin spine and otolith cross sections from juvenile lake sturgeon (ages 2-11) was similar, although pectoral spines were clearer and easier to interpret. A power function (true age = [estimated age](1.054796), where estimated age was determined from pectoral spines; r(2) = 0.98) provides a means for correcting existing age estimates obtained from lake sturgeon pectoral fin spines.},
	issn = {0002-8487},
	doi = {10.1577/T08-098.1},
	author = {Bruch, R. M. and Campana, S. E. and Davis-Foust, S. L. and Hansen, M. J. and Janssen, J.}
}
@article {312,
	title = {Bomb radiocarbon chronologies in the Arctic, with implications for the age validation of lake trout (Salvelinus namaycush) and other Arctic species},
	journal = {Canadian Journal of Fisheries and Aquatic Sciences},
	volume = {65},
	year = {2008},
	note = {id: 804; 285MD Times Cited:7 Cited References Count:41Y},
	pages = {733-743},
	abstract = {Radiocarbon generated by atmospheric testing of nuclear weapons (bomb radiocarbon) produced a strong signal with an abrupt onset in the 1950s, which serves as a dated marker for tracing oceanic circulation and confirming age in animals forming growth bands. Here, we report the first prebomb and postbomb radiocarbon chronologies for marine and freshwater environments in the Canadian Arctic, extend the radiocarbon chronology for the northwest Atlantic Ocean, and use the onset of the bomb signal to validate our age interpretations of lake trout (Salvelinus namaycush) in Arctic lakes. Both surface and deepwater Arctic chronologies became detectable on or around 1958, similar to the year of onset elsewhere in the world. In contrast, the freshwater Arctic chronology increased sharply in 1957, with a peak value sixfold higher than the adjacent marine environment. The radiocarbon content of the adult otolith core validated our age interpretation criteria for Arctic lake trout to an age of at least 50 years. Otolith growth in such slow-growing fish was so low as to be unresolvable under conventional examination with a dissecting microscope. With these new radiocarbon reference chronologies, age validation of a large number of Arctic organisms should now be possible.},
	issn = {0706-652X},
	doi = {10.1139/F08-012},
	author = {Campana, S. E. and Casselman, J. M. and Jones, C. M.}
}
@article {311,
	title = {Growth analysis and age validation of a deepwater Arctic fish, the Greenland halibut (Reinhardtius hippoglossoides)},
	journal = {Canadian Journal of Fisheries and Aquatic Sciences},
	volume = {65},
	year = {2008},
	note = {id: 806; 322ER Times Cited:3 Cited References Count:56Y},
	pages = {1047-1059},
	abstract = {The accuracy of age interpretations on a deep-sea, Arctic fish species, the Greenland halibut (Reinhardtius hippoglossoides) was tested using several age validation methods. Consistent annual growth increments were either not formed or not visible in either whole or sectioned otoliths from three fish marked with oxytetracyline and recaptured after 2-4 years at liberty. Bomb radiocarbon assays based on a local reference chronology indicated that both whole and sectioned otoliths underestimated age by 1-15 years, with an average of 6 years. Growth rates estimated using the tag recapture model GROTAG were consistent with growth rates based on the radiocarbon assays and were less than half that of previously reported growth rates. The failure of otolith sections to provide an accurate age is unusual, but may be symptomatic of very slow-growing species with unusually shaped otoliths. Greenland halibut living in the deep-sea, Arctic environment are slower growing and longer lived than previously suspected, suggesting that the age-structured basis for current fisheries management warrants careful examination. Our results highlight the importance of using rigorous tests of ageing accuracy for exploited species and confirm that such age validation methods can be applied successfully in challenging environments such as the deep sea or the Arctic.},
	issn = {0706-652X},
	doi = {10.1139/F08-030},
	author = {Treble, M. A. and Campana, S. E. and Wastle, R. J. and Jones, C. M. and Boje, J.}
}
@article {309,
	title = {A validated description of age and growth of western Atlantic bluefin tuna (Thunnus thynnus)},
	journal = {Canadian Journal of Fisheries and Aquatic Sciences},
	volume = {65},
	year = {2008},
	note = {id: 805; 348EN Times Cited:4 Cited References Count:12Y},
	pages = {1523-1527},
	abstract = {Current stock assessments of western Atlantic bluefin tuna (Thunnus thymus) use age-structured population analyses, but the age assignment in the population model is made using all age-length relationship derived from mark and recapture studies largely completed during the 1970s. In our study, the deposition of bomb radiocarbon was used as a dated mark to validate age inferences of bluefin tuna and to compare the validated ages with those predicted from the age-length relationship. The results support the view that the age-length relationship currently in use for the assessment overestimates growth rate and the ultimate size of the fish. These findings have implications for the estimation of stock productivity and may negatively impact the rebuilding schedules established by fisheries managers.},
	issn = {0706-652X},
	doi = {10.1139/F08-127},
	author = {Neilson, J. D. and Campana, S. E.}
}
@article {359,
	title = {Age under-estimation in New Zealand porbeagle sharks (Lamna nasus): is there an upper limit to ages that can be determined from shark vertebrae?},
	journal = {Marine and Freshwater Research},
	volume = {58},
	year = {2007},
	note = {id: 1857; 131AF Times Cited:5 Cited References Count:60Y},
	pages = {10-23},
	abstract = {Annual deposition of growth bands in vertebrae has been validated for many shark species, and is now widely regarded as the norm. However, vertebrae are part of the shark{\textquoteright}s axial skeleton, and band deposition may stop in old sharks when somatic growth ceases. We aged vertebral sections from New Zealand porbeagle sharks (Lamna nasus) under reflected white light and using X-radiographs. Bomb radiocarbon assays supported vertebral age estimates up to similar to 20 years, but not at older ages. The results suggest that older porbeagles were under-aged by as much as 50\% from vertebral band counts, presumably because band width declined to a point where it became unresolvable. This has important implications for growth studies on other long-lived sharks. Estimated ages at sexual maturity were 8-11 years for males and 15-18 years for females, and longevity may be similar to 65 years. New Zealand and North Atlantic porbeagles differ in these parameters, and in length at maturity and maximum length, suggesting genetic isolation of the two populations.},
	issn = {1323-1650},
	doi = {10.1071/Mf06069},
	author = {Francis, M. P. and Campana, S. E. and Jones, C. M.}
}
@article {351,
	title = {Validated age, growth, and mortality estimates of the ocean quahog (Arctica islandica) in the western Atlantic},
	journal = {Ices Journal of Marine Science},
	volume = {64},
	year = {2007},
	note = {id: 807; 173HY Times Cited:6 Cited References Count:51Y},
	pages = {31-38},
	abstract = {The age structure of offshore (Sable Bank) and inshore (St Mary{\textquoteright}s Bay) populations of eastern Canadian ocean quahogs (Arctica islandica), and of a northwestern Iceland population, is investigated. Age estimates for eastern Canadian ocean quahogs were validated through analysis of bomb-produced C-14 in quahog shell growth increments deposited before, during, and after the atmospheric atomic bomb testing periods of the 1950s and 1960s. Delta 14C from shells with presumed birthdates between the late 1950s and 1970s clearly reflects the sharp increase in oceanic radiocarbon attributable to nuclear testing. The results validate our age interpretations of Sable Bank quahogs to an age of 45 y, and support longevity estimates of more than 200 y for the same population. Longevity calculations for the other populations exceeded 60 y. Von Bertalanffy growth parameters were estimated for the three populations, the growth rate of all three was relatively rapid for the first 20 - 30 y of life, but thereafter was very slow. The instantaneous rate of natural mortality (M), calculated using the age-frequency distribution of the unexploited populations, was estimated to be 0.03 and 0.10 for the Sable Bank and St Mary{\textquoteright}s Bay populations, respectively.},
	issn = {1054-3139},
	doi = {10.1093/icesjms/fsl001},
	author = {Kilada, R. W. and Campana, S. E. and Roddick, D.}
}
@article {612,
	title = {Bomb dating and age validation using the spines of spiny dogfish (Squalus acanthias)},
	journal = {Environmental Biology of Fishes},
	volume = {77},
	year = {2006},
	note = {107bsTimes Cited:38Cited References Count:25},
	month = {Dec},
	pages = {327-336},
	abstract = {Bomb radiocarbon has previously been used to validate the age of large pelagic sharks based on incorporation into vertebrae. However, not all sharks produce interpretable vertebral growth bands. Here we report the first application of bomb radiocarbon as an age validation method based on date-specific incorporation into spine enamel. Our results indicate that the dorsal spines of spiny dogfish, Squalus acanthias, recorded and preserved a bomb radiocarbon pulse in growth bands formed during the 1960s with a timing which was very similar to that of marine carbonates. Using radiocarbon assays of spine growth bands known to have formed in the 1960s and 1970s as a dated marker, we confirm the validity of spine enamel growth band counts as accurate annual age indicators to an age of at least 45 year. Radiocarbon incorporation into northeast Atlantic dogfish spines occurred in similar years as those in the northwest Atlantic and northeast Pacific, although the amount of radiocarbon differed in keeping with the radiocarbon content of the different water masses. Published reports suggesting that Pacific dogfish are longer lived and slower growing than their Atlantic counterparts appear to be correct, and are not due to errors in interpreting the spine growth bands. Radiocarbon assays of fin spine enamel appears to be well suited to the age validation of sharks with fin spines which inhabit the upper 200 m of the ocean.},
	issn = {0378-1909},
	doi = {10.1007/s10641-006-9107-3},
	author = {Campana, S. E. and Jones, C. and McFarlane, G. A. and Myklevoll, S.}
}
@article {675,
	title = {Bomb radiocarbon dating calibrates beluga (Delphinapterus leucas) age estimates},
	journal = {Canadian Journal of Zoology-Revue Canadienne De Zoologie},
	volume = {84},
	year = {2006},
	note = {140vdTimes Cited:51Cited References Count:73},
	month = {Dec},
	pages = {1840-1852},
	abstract = {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.},
	issn = {0008-4301},
	doi = {10.1139/Z06-182},
	author = {Stewart, R. E. A. and Campana, S. E. and Jones, C. M. and Stewart, B. E.}
}
@article {1020,
	title = {Otolith science entering the 21st century},
	journal = {Marine and Freshwater Research },
	volume = {56},
	year = {2005},
	note = {id: 1044},
	pages = {485-495},
	abstract = {A review of 862 otolith-oriented papers published since the time of the 1998 Otolith Symposium in Bergen, Norway suggests that there has been a change in research emphasis compared to earlier years. Although close to 40\% of the papers could be classifed as {\textquoteleft}annual age and growth{\textquoteright} studies, the remaining papers were roughly equally divided between studies of otolith microstructure, otolith chemistry and non-ageing applications. A more detailed breakdown of subject areas identified 15 diverse areas of specialisation, including age determination, larval fish ecology, population dynamics, species identification, tracer applications and environmental reconstructions. For each of the 15 subject areas, examples of representative studies published in the last 6 years were presented, with emphasis on the major developments and highlights. Among the challenges for the future awaiting resolution, the development of novel methods for validating the ages of deepsea fishes, the development of a physiologically-based otolith growth model, and the identification of the limits (if any) of ageing very old fish are among the most pressing.},
	doi = {10.1071/MF04147},
	author = {Campana, S. E.}
}
@article {641,
	title = {Age determination, validation and growth of Grand Bank yellowtail flounder (Limanda ferruginea)},
	journal = {Ices Journal of Marine Science},
	volume = {60},
	year = {2003},
	note = {723jaTimes Cited:43Cited References Count:57},
	month = {Oct},
	pages = {1123-1138},
	abstract = {Yellowtail flounder (Limanda ferruginea) (Storer, 1839) on the Grand Bank off Newfoundland were traditionally aged using surface-read whole otoliths. Age determination of otoliths from recaptures of fish tagged in the early 1990s indicated that the traditional ageing technique was underestimating the ages of yellowtail flounder when compared with the time at liberty. Age comparisons between whole and thin-sectioned otoliths showed agreement in age readings up to 7 years; thereafter whole otoliths tended to give much lower ages than those estimated by thin sections. Length-frequency analysis of pelagic and demersal juveniles, captive rearing of juveniles and marginal increment analysis all corroborated age determination based on thin sections. Tag-recaptures and bomb radiocarbon assays validated age interpretations based on thin sections in young and old yellowtail flounder, respectively. Ages were validated up to 25 years for females and 21 years for males. However, because of increased narrowing of annuli in thin-sectioned otoliths from old fish, even thin sections may underestimate the true age of the fish. von Bertalanfly growth curve parameters (combined sexes) were L-infinity = 55.6 cm total length, K = 0.16 and t(0) = -0.003. These results challenge the conventional view that yellowtail flounder on the Grand Banks are a relatively fast growing, short-lived species. Crown Copyright (C) 2003 Published by Elsevier Ltd on behalf of International Council for the Exploration of the Sea. All rights reserved.},
	issn = {1054-3139},
	doi = {10.1016/S1054-3139(03)00125-5},
	author = {Dwyer, K. S. and Walsh, S. J. and Campana, S. E.}
}
@article {715,
	title = {Suitability of glycerin-preserved otoliths for age validation using bomb radiocarbon},
	journal = {Journal of Fish Biology},
	volume = {63},
	year = {2003},
	note = {734gqTimes Cited:5Cited References Count:9},
	month = {Oct},
	pages = {848-854},
	abstract = {The effect of glycerin storage on the bomb radiocarbon content of otoliths was determined experimentally. Storage in either pre- or post-bomb glycerin had no detectable effect on the bomb radiocarbon content of either pre- or post-bomb otoliths. Therefore bomb-dated age validation studies need not be restricted to freshly-collected samples or dry otoliths, implying that the large numbers of glycerin-archived otoliths around the world are suitable for age validation studies using bomb radiocarbon. (C) 2003 The Fisheries Society of the British Isles.},
	issn = {0022-1112},
	doi = {10.1046/j.1095-8649.2003.00174.x},
	author = {Campana, S. E. and Stanley, R. D. and Wischniowski, S.}
}
@article {677,
	title = {Bomb dating and age determination of large pelagic sharks},
	journal = {Canadian Journal of Fisheries and Aquatic Sciences},
	volume = {59},
	year = {2002},
	note = {548ceTimes Cited:98Cited References Count:16},
	month = {Mar},
	pages = {450-455},
	abstract = {Despite their notoriety and role as apex predators, the longevity of large pelagic sharks such as the porbeagle (Lamna nasus) and shortfin mako (Isurus oxyrinchus) is unknown. Vertebral growth bands provide an accurate indicator of age in young porbeagle, but age validation has never been reported for any large shark species past the age of sexual maturity. Here, we report the first application of bomb radiocarbon as an age validation method for long-lived sharks based on date-specific incorporation of radiocarbon into vertebral growth bands. Our results indicate that porbeagle vertebrae recorded and preserved a bomb radiocarbon pulse in growth bands formed during the 1960s. Through comparison of radiocarbon assays in young, known-age porbeagle collected in the 1960s with the corresponding growth bands in old porbeagle collected later, we confirm the validity of porbeagle vertebral growth band counts as accurate annual age indicators to an age of at least 26 years. The radiocarbon signatures of porbeagle vertebral growth bands appear to be temporally and metabolically stable and derived mainly from the radiocarbon content of their prey. Preliminary radiocarbon assays of shortfin mako vertebrae suggest that current methods for determining shortfin mako age are incorrect.},
	issn = {0706-652x},
	doi = {10.1139/F02-027},
	author = {Campana, S. E. and Natanson, L. J. and Myklevoll, S.}
}
