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Title: Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon,
Description: Rockfishes (Sebastes spp.) support one of the most economically important fisheries of the Pacific Northwest and it is essential for sustainable management that age estimation procedures be validated for these species. Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon (14C) signal in the ocean environment that scientists have identified as a useful tracer and chronological marker in natural systems. In this study, we first demonstrated that fewer samples are necessary for age validation using the bomb-generated 14C signal by emphasizing the utility of the time-specific marker created by the initial rise of bomb-14C. Second, the bomb-generated 14C signal retained in fish otoliths was used to validate the age and age estimation method of the quillback rockfish (Sebastes maliger) in the waters of southeast Alaska. Radiocarbon values from the first year's growth of quillback rockfish otoliths were plotted against estimated birth year to produce a 14C time series spanning 1950 to 1985. The initial rise in bomb-14C from prebomb levels (∼ -90‰) occurred in 1959 [±1 year] and 14C levels rose relatively rapidly to peak Δ14C values in 1967 (+105.4‰) and subsequently declined through the end of the time series in 1985 (+15.4‰). The agreement between the year of initial rise of 14C levels from the quillback rockfish time series and the chronology determined for the waters of southeast Alaska from yelloweye rockfish (S. ruberrimus) otoliths validated the aging method for the quillback rockfish. The concordance of the entire quillback rockfish 14C time series with the yelloweye rockfish time series demonstrated the effectiveness of this age validation technique, confirmed the longevity of the quillback rockfish up to a minimum of 43 years, and strongly confirms higher age estimates of up to 90 years., Cited By (since 1996):22, Fish and Fisheries, CODEN: FSYBA, ,
Author: Kerr, Andrews, Munk, Coale, Frantz, Cailliet, Brown
Date: 2005-01-01T00:00:00Z

Title: Bomb radiocarbon and lead-radium disequilibria in otoliths of bocaccio rockfish (Sebastes paucispinis),
Description: 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. © CSIRO 2005., Cited By (since 1996):18, Fish and Fisheries, CODEN: AJMFA, ,
Author: Andrews, Burton, Kerr, Cailliet, Coale, Lundstrom, Brown
Date: 2005-01-01T00:00:00Z

Title: Radiocarbon in otoliths of yelloweye rockfish (Sebasfes ruberrimus): A reference time series for the coastal waters of southeast Alaska,
Description: Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon (14C) signal that has provided a useful tracer and chronological marker in oceanic systems and organisms. The bomb-generated 14C signal retained in fish otoliths can be used as a time-specific recorder of the 14C present in ambient seawater, making it a useful tool in age validation of fishes. The goal of this study was to determine 14C in otoliths of the age-validated yelloweye rockfish (Sebastes ruberrimus) to establish a reference time series for the coastal waters of southeast Alaska. Radiocarbon values from the first year's growth of 43 yelloweye rockfish otoliths plotted against estimated birth year produced a 14C time series (1940-1990) for these waters. The initial rise of 14C occurred in 1958 and 14C levels rose to peak values (60-70‰) between 1966 and 1971, with a subsequent declining trend through the end of the record in 1990 (-3.2‰). In addition, the 14C data confirmed the longevity of the yelloweye rockfish to a minimum of 44 years and strongly support higher age estimates. This 14C time series will be useful for the interpretation of 14C accreted in biological samples from these waters., Cited By (since 1996):24, CODEN: CJFSD, ,
Author: Kerr, Andrews, Frantz, Coale, Brown, Cailliet
Date: 2004-01-01T00:00:00Z

Title: Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon,
Description: Cited By (since 1996):26, , , ,
Author: Kerr, Andrews, Munk, Coale, Frantz, Cailliet, Brown
Date: 2005-01-01T00:00:00Z

Title: Investigations of Δ14C, δ13C, and δ15N in vertebrae of white shark (Carcharodon carcharias) from the eastern North Pacific Ocean,
Description: The white shark, Carcharodon carcharias, has a complex life history that is characterized by large scale movements and a highly variable diet. Estimates of age and growth for the white shark from the eastern North Pacific Ocean indicate they have a slow growth rate and a relatively high longevity. Age, growth, and longevity estimates useful for stock assessment and fishery models, however, require some form of validation. By counting vertebral growth band pairs, ages can be estimated, but because not all sharks deposit annual growth bands and many are not easily discernable, it is necessary to validate growth band periodicity with an independent method. Radiocarbon (14C) age validation uses the discrete 14C signal produced from thermonuclear testing in the 1950s and 1960s that is retained in skeletal structures as a time-specific marker. Growth band pairs in vertebrae, estimated as annual and spanning the 1930s to 1990s, were analyzed for Δ14C and stable carbon and nitrogen isotopes (δ13C and δ15N). The aim of this study was to evaluate the utility of 14C age validation for a wide-ranging species with a complex life history and to use stable isotope measurements in vertebrae as a means of resolving complexity introduced into the 14C chronology by ontogenetic shifts in diet and habitat. Stable isotopes provided useful trophic position information; however, validation of age estimates was confounded by what may have been some combination of the dietary source of carbon to the vertebrae, large-scale movement patterns, and steep 14C gradients with depth in the eastern North Pacific Ocean., Cited By (since 1996):28, CODEN: EBFID, ,
Author: Kerr, Andrews, Cailliet, Brown, Coale
Date: 2006-01-01T00:00:00Z

Title: Radiocarbon in otoliths of yelloweye rockfish (Sebasfes ruberrimus): A reference time series for the coastal waters of southeast Alaska,
Description: Cited By (since 1996):26, , , ,
Author: Kerr, Andrews, Frantz, Coale, Brown, Cailliet
Date: 2004-01-01T00:00:00Z

Title: 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,
Description: , , , ,
Author: Andrews, Burton, Kerr, Cailliet, Coale, Lundstrom, Brown

Title: Investigations of Δ14C, δ13C, and δ15N in vertebrae of white shark (Carcharodon carcharias) from the eastern North Pacific Ocean,
Description: Cited By (since 1996):35, , , ,
Author: Kerr, Andrews, Cailliet, Brown, Coale
Date: 2006-01-01T00:00:00Z