Models in fish population dynamics
The use of population dynamics models is essential to provide assessment of the fish abundance
and advice on management and strategies for the fisheries. The stock-recruitment curve define
the relationship between the spawning stock and the subsequent recruitment, describing nature's
regulation of population size, whether or not the populations are being exploited. The two classical
relations, established by Ricker and Shepherd, are:
R (S) = b1S e-b2S
, b1, b2 > 0 (4)
R (S) = S
b1 + b2Sb3
, b1, b2, b3 > 0
where S is the spawning stock and R is the recruitment, i.e.






