The optimal (or critical) age is the transition point when a cohort achieves its maximum biomass in the absemce of fishing, i.e. losses due to natural mortality are now greater than gains due to increase in individual biomass.
Examples
data(ple4)
ageopt(ple4)
#> An x of class "FLQuant"
#> , , unit = unique, season = all, area = unique
#>
#> year
#> age 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
#> all 4 5 6 7 8 9 9 8 8 8 7 7 9 9
#> year
#> age 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985
#> all 6 6 6 7 6 7 9 9 9 6 6 8 7 7
#> year
#> age 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
#> all 9 8 8 9 8 8 9 8 9 9 9 6 6 7
#> year
#> age 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
#> all 7 9 9 9 9 9 9 7 8 8 8 6 7 9
#> year
#> age 2014 2015 2016 2017
#> all 7 8 8 8
#>
#> units: