|Title||A stock-recruitment model for highly fecund species based on temporal and spatial extent of spawning|
|Publication Type||Journal Article|
|Year of Publication||2013|
|Authors||Maunder MN, Deriso R.B|
|Type of Article||Article|
|Keywords||density dependence; dependent habitat selection; fish stocks; Fisheries management; management; productivity; recruitment; Stock assessment; Stock-recruitment|
A stock-recruitment model is described for highly fecund species based on the contraction of the spatial and temporal extent of spawning when a population is reduced in size: R = alpha K(1 - exp[-S/(mK)]), where S is the number of spawners, K is the carrying capacity in units of the number of habitat patches that can produce recruits, a is the average number of recruits per unit of habitat, and m is the number of spawners that group. together to spawn. The model is based on three simplifying assumptions: (1) the environment is divided into K units; (2) the presence of one spawner provides sufficient eggs to fill the capacity of that unit, any additional spawners in that unit will not increase recruitment; and (3) groups of fish are randomly distributed over the environment. The model allows for a flat top curve, which is consistent with highly fecund species that are continuous spawners and do not aggregate to spawn. It also allows for a strong relationship between spawners and recruits, which is more consistent with species that aggregate in time and space to spawn. This stock-recruitment model can be approximated in terms of parameters commonly used in contemporary stock assessment models (virgin recruitment, R-0, and steepness of the stock-recruitment relationship, h, virgin spawning biomass, S-0): R = R-0(1 - exp(5ln(1 - h)S/S-0)). The functional form is compared with the Beverton-Holt stock-recruitment model. (C) 2013 Elsevier B.V. All rights reserved.
|Short Title||Fish Res.|