Age determination for managed and assessed coastal pelagic species in the Northeast Pacific

In this paper, we describe historical and contemporary ageing methods that were developed and applied in the five primary CPS ageing laboratories (National Oceanic and Atmospheric Administration [NOAA] Southwest Fisheries Science Center [SWFSC], California Department of Fish and Wildlife [CDFW], Washington Department of Fish and Wildlife ([WDFW], Centro Interdisciplinario de Ciencias Marinas [CICIMAR, Mexico], and Pacific Biological Station [PBS] of the Department of Fisheries and Oceans [DFO, Canada]), with particular emphasis on whole otolith surface ageing, the current ageing method used for all three species. Whole otolith processing and ageing methods used for each species are described in separate sections, with graphical supports from two main sources: 1) validation research of annual increment deposition in otoliths of laboratory-reared fish; and 2) studies of seasonal and quarterly patterns of marginal increment formation in otoliths of wild-caught fish. Age corroboration procedures for ensuring ageing consistency and computing ageing errors within each laboratory are also presented. Finally, we propose future research to improve ageing methods and their standardization.