290
13. Nile Perch Population Dynamics in Lake Victoria :
births[10] = IF(cohort_spawned = 10)
THEN (Tot_spawned_biomass *larval_survivorship) ELSE 0
{biomass born}
births [11] = IF (cohort_spawned = 11)
THEN (Tot_spawned_biomass *larval_survivorship) ELSE 0
{biomass born}
births [12] = IF (cohort_spawned = 12)
THEN (Tot_spawned_biomass*larval_survivorship) ELSE 0
{biomass born}
births[13] = IF (cohort_spawned = 13)
THEN (Tot_spawned_biomass*larval_survivorship) ELSE 0
{biomass born}
births[14] = IF (cohort_spawned = 14)
THEN (Tot_spawned_biomass*larval_survivorship) ELSE 0
{biomass born}
births[15] = IF (cohort_spawned = 15)
THEN (Tot_spawned_biomass*larval_survivorship) ELSE 0
{biomass born}
births[16] = IF (cohort_spawned = 16)
THEN (Tot_spawned_biomass *larval_survivorship) ELSE 0
{biomass born}
births[17] = IF (cohort_spawned = 17)
THEN (Tot_spawned_biomass*larval_survivorship) ELSE 0
{biomass born}
births[18] = IF (cohort_spawned = 18)
THEN (Tot_spawned_biomass*larval_survivorship) ELSE 0
{biomass born}
births[19] = IF (cohort_spawned = 19)
THEN (Tot_spawned_biomass*larval_survivorship) ELSE 0
{biomass born}
births[20] = IF (cohort_spawned = 20)
THEN (Tot_spawned_biomass*larval_survivorship) ELSE 0
{biomass born}
fished[Cohorts] = IF(Fishwt[Cohorts]>minimum_size) THEN
1 ELSE 0
fished_mortality [Cohorts] = IF(Total_fishable_mass< =
0) THEN 0 ELSE(IF(Fishwt[Cohorts]>minimum_size)
THEN((NP_mass[Cohorts] /Total_fishable_mass)*Total_fishi
ng_intensity) ELSE 0) {mass of fish fished per cohort
per day}
Fishwt[Cohorts] = IF(NP_mass[Cohorts] = 0) OR
(NP_number[Cohorts] = 0) THEN 0
ELSE(NP_mass[Cohorts] /NP_number[Cohorts])