... by smaller and youn - ger individuals. However, a large and relatively abrupt in - crease in length-at-age and weight-at-length (Marshall et al.2004) and in the proportion mature-at-length occurred ... length-basedestimate of SSB (len-SSB) would be estimated as(2)len-SSB =⋅⋅∑nmwllllwhere nl, ml, and wlare the numbers-at-length, proportionmature-at-length, and weight-at-length, ... Atlantic cod, SSB is es-timated by the ICES AFWG as(1)SSB =⋅⋅=+∑nmwaaaa313where na, ma, and waare the numbers-at-age, proportionmature-at-age, and weight-at-age, respectively...