@article {10,
	title = {Incorporation of bomb-produced 14C into fish otoliths: A novel approach for evaluating age validation and bias with an application to yellowfin sole and northern rockfish},
	journal = {Ecological Modelling},
	volume = {320},
	year = {2016},
	pages = {79-91},
	abstract = {Fish age validation with bomb-produced radiocarbon (14C) requires a known-age Δ14C reference chronology spanning the era of a marine increase in bomb-produced 14C (1950s to 1960s). Concordance between otolith Δ14C in a validation sample and the reference chronology indicates accurate test ages. Here, we present an information-theoretic approach to hypothesis testing and use Bayesian data analysis with Markov chain Monte Carlo simulation as a probabilistic framework to quantitatively estimate age determination bias and its uncertainty. Using this approach, we compare a new Δ14C reference chronology from the eastern Bering Sea and a previously established reference from the Gulf of Alaska with otolith Δ14C in two validation species, eastern Bering Sea yellowfin sole (Limanda aspera) and Gulf of Alaska northern rockfish (Sebastes polyspinis). Our goals were twofold: (i) to validate the age determination methods for northern rockfish and yellowfin sole using comparisons within oceanic basins, and (ii) to explore the outcome of making na{\"\i}ve comparisons of these validation data sets to reference chronologies across oceanic basins. Based on within-basin comparisons we concluded that estimated ages for eastern Bering Sea yellowfin sole and Gulf of Alaska northern rockfish were accurate. We further concluded that there were important differences in otolith 14C uptake between fish from the two ocean basins.},
	issn = {0304-3800},
	doi = {10.1016/j.ecolmodel.2015.09.013},
	url = {http://www.sciencedirect.com/science/article/pii/S0304380015004354},
	author = {Kastelle, Craig R. and Helser, Thomas E. and Wischniowski, Stephen G. and Loher, Timothy and Goetz, Betty J. and Kautzi, Lisa A.}
}
@article {13,
	title = {Incorporation of bomb-produced 14C into fish otoliths. An example of basin-specific rates from the North Pacific Ocean},
	journal = {Canadian Journal of Fisheries and Aquatic Sciences},
	volume = {72},
	year = {2015},
	pages = {879-892},
	issn = {0706-652X},
	doi = {10.1139/cjfas-2014-0225},
	url = {http://dx.doi.org/10.1139/cjfas-2014-0225},
	author = {Wischniowski, Stephen G. and Kastelle, Craig R. and Loher, Timothy and Helser, Thomas E.}
}
@article {58,
	title = {Modeling environmental factors affecting assimilation of bomb-produced Δ14C in the North Pacific Ocean: Implications for age validation studies},
	journal = {Ecological Modelling},
	volume = {277},
	year = {2014},
	pages = {108-118},
	abstract = {The bomb-produced radiocarbon (14C) chronometer has become the gold standard for assessing the accuracy of otolith growth ring based fish age estimates. In the northeast Pacific Ocean, nearly a dozen age validation studies have been conducted, ranging from California to Alaska, most of which have relied on a single reference chronology from the Gulf of Alaska. We developed a Bayesian hierarchical model using data sets of bomb-produced radiocarbon in the northeast Pacific Ocean and investigated whether latitude and upwelling exerts an influence on the parameters that describe the rapid Δ14C increase in marine calcium carbonates. Models incorporating both latitude and upwelling as linear covariates of a 4-parameter logistic model were favored based on ΔDIC statistics. There was substantial evidence to support that the timing of the Δ14C pulse was advanced and that total Δ14C uptake increased with increasing latitude. In contrast, increased oceanographic upwelling resulted in lower total radiocarbon input as well as a delay in the timing of the pulse curve, as was demonstrated in the upwelling dominated California Current System. Within the observed latitudinal and upwelling range of the data sets examined in this study the predicted timing of the bomb pulse curve varied by as much as 3 years, which could be misinterpreted as aging error. Our results suggest that new reference chronologies may be needed for regions of the North Pacific Ocean differing in latitude, seasonal upwelling strength and other mixing factors that can potentially change the functional form of the Δ14C curve.},
	issn = {0304-3800},
	doi = {10.1016/j.ecolmodel.2014.01.011},
	url = {http://www.sciencedirect.com/science/article/pii/S0304380014000453},
	author = {Helser, Thomas E. and Kastelle, Craig R. and Lai, Han-lin}
}
@article {204,
	title = {Bomb-produced radiocarbon validation of growth-increment crossdating allows marine paleoclimate reconstruction},
	journal = {Palaeogeography, Palaeoclimatology, Palaeoecology},
	volume = {311},
	year = {2011},
	note = {id: 2167},
	pages = {126-135},
	abstract = {The bivalve Pacific geoduck (Panopea generosa) has been used in the eastern North Pacific Ocean to create proxies for environmental factors such as temperature and oceanographic conditions. This type of research depends upon accurate age determination of Pacific geoducks, which historically was based on shell growth-increment counts. A recent study comparing age estimates generated by the dendrochronology (tree-ring science) procedure of crossdating to those estimated from growth-increment counts found a significant difference between the methods for geoduck older than 30 years. Compared to the traditional age determination method of counting growth increments, the crossdating method estimates a greater longevity in this species, with some individuals living in excess of 150 years. In the present study, the accuracy of each method was independently assessed using bomb-produced radiocarbon (14C) techniques. Specimens whose birth years were estimated to be within the era of the bomb-produced marine 14C increase and where the differences between ages estimated by the two methods were greatest were selected for 14C analysis. The difference between age estimates from traditional growth-increment counts and those from crossdating was evaluated using their respective 14C chronologies in comparisons to a reference chronology as a standard. The comparisons relied on Bayesian nonlinear models using Markov Chain Monte Carlo simulation. This method of analysis showed that with a 50\% probability geoducks were aged correctly when using the crossdating method, compared to the growth increment counts which had a 50\% probability of underestimating the age by 4 years. Therefore, the crossdated age estimates were found to be more accurate than increment counts. Furthermore, these results provide new confidence in using Pacific geoduck biochronologies for paleoclimate and paleoenvironmental reconstruction.},
	issn = {0031-0182},
	doi = {10.1016/j.palaeo.2011.08.015},
	url = {http://www.sciencedirect.com/science/article/pii/S0031018211004524},
	author = {Kastelle, Craig R. and Helser, Thomas E. and Black, Bryan A. and Stuckey, Matthew J. and C. Gillespie, Darlene and McArthur, Judy and Little, Diana and D. Charles, Karen and Khan, Reziah S.}
}
