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Full-Text Articles in Aquaculture and Fisheries
A General Theory Of Age-Length Keys: Combining The Forward And Inverse Keys To Estimate Age Composition From Incomplete Data, Lisa E. Ailloud, John M. Hoenig
A General Theory Of Age-Length Keys: Combining The Forward And Inverse Keys To Estimate Age Composition From Incomplete Data, Lisa E. Ailloud, John M. Hoenig
VIMS Articles
There are two approaches to estimating age composition from a large number of length observations and a limited number of age determinations: the forward and the inverse age-length keys. The forward key looks at the distribution of age within each length bin while the inverse key looks at the distribution of length at each age. The former is more precise but has stringent requirements for the way data are collected. The latter approach is more widely applicable. We review the theory of the two keys with particular attention to necessary assumptions and the restrictions on when the methods are applicable. …
Estimating Age Composition For Multiple Years When There Are Gaps In The Ageing Data: The Case Of Western Atlantic Bluefin Tuna, Lisa E. Ailloud, Matthew V. Lauretta, John F. Walter Iii, John M. Hoenig
Estimating Age Composition For Multiple Years When There Are Gaps In The Ageing Data: The Case Of Western Atlantic Bluefin Tuna, Lisa E. Ailloud, Matthew V. Lauretta, John F. Walter Iii, John M. Hoenig
VIMS Articles
Age–length key (ALK) methods generally perform well when length samples and age samples are representative of the underlying population. It is unclear how well these methods perform when lengths are representative but age samples are sparse (i.e. age samples are small or missing in many years, and some length groups do not have any age observations). With western Atlantic bluefin tuna, the available age data are sparse and have been, for the most part, collected opportunistically. We evaluated two methods capable of accommodating sparse age data: a novel hybrid ALK (combining forward ALKs and cohort slicing) and the combined forward-inverse …