13.5. Questions and Tasks
291
fish_mort [Cohorts] = IF (F i s hwt [Cohorts]< = 0) THEN 0
ELSE(fished_mortality[Cohorts] /Fishwt[Cohorts]) {number
of fish f ished per day }
growth_haps [Cohorts] = I F (Fi s hwt [Cohor t s] = 0 ) THEN 0
ELSE(.067 * (Fi s hwt[Cohort s] A- . 409 »
growth_other [Coh or t s] = I F(Fishwt [Cohorts ] = 0 ) THEN 0
ELSE(.04 8 * (Fi shw t[ Coho rt s] A- . 4l 9 »
Natural_Mortality [1 ] =
(NP_mass[l]*can[l] *Fishwt[l] *sus_mass[l] ) *O
Natural_Mortality [2] = (I F (Fi s hwt [1 ] > ( . 3 *Fi s hwt [2 ] »
AND (sus_mass [1]>0)
THEN(can[1] *(NP_mass[2] /sus_mass[1]» ELSE 0)
Natural_Mortali ty[ 3] = (IF(Fishwt[1]>(.3*Fishwt[3]»
AND (sus_mass [1]>0)
THEN(can[1]*(NP_mass[3] /sus_mass[1]») ELSE
0)+(IF(Fishwt[2]>(. 3*Fishwt[3]» AND (sus_mass [2]>0)
THEN(can[ 2]*(NP_mass[3] /sus_mass[2]» ELSE 0)
Natural_Mortality [4] = (IF(Fishwt[1]>(.3 *Fishwt[4]»
AND (sus_mass [1]>0 )
THEN(can [1] * (NP_mass[4] /sus_mass[1]» ELSE
0)+(IF(Fishwt[ 2]> (.3 *Fishwt[4]» AND (sus_mass [2]>0)
THEN(can[ 2] * (NP_ma s s[ 4 ] / s u s _ma s s [2 ]» ELSE
0)+ (IF (Fishwt [3]> (. 3 *Fishwt [4]» AND (s us _ma s s [ 3 ] >0 )
THEN (can[ 3]* (NP_mass [4 ] /sus_mass[3 ] » ELSE 0 )
Natural_Mortali t y [ 5] = ( I F( Fi s hwt[ 1 ] >(.3* Fi s hwt[ 5 ]»
AND (sus_mass [1 ]>0 )
THEN(can[1 ] *(NP_mass[5 ] /sus_mass[1]» ELSE
0) + (I F( Fi s hwt[2 ] > ( .3*Fi s hwt [51» AND (sus_mas s [21> 0 )
THEN(can [2]*(NP_mass[5] /sus_mass[ 2]» ELSE
0)+(IF(Fishwt[ 3] >(. 3 *Fishwt[5]» AND (sus_mass [3]>0)
THEN(can [3]*(NP_mass[5] /sus_mass[3] » ELSE
0)+(IF(Fishwt[41>(. 3*F ishwt[5 ]» ) AND (sus_mass[4]>0)
THEN(can[4]*(NP_mass[5] /sus_mass[4]») ELSE 0)
Natural_Mortali ty [6] = (IF (Fishwt[1]>(.3 *Fishwt[6]})
AND (sus_mass [1]>0)
THEN(can[l]*(NP_mass[6] /sus_mass[1]}) ELSE
0)+(IF(Fishwt[ 2]>(.3*Fishwt[6]» AND (sus_mass [2]>0)
THEN(can[2] * (NP_mass[6] /sus_mass[2]» ELSE
0)+(IF(Fishwt [3]>(. 3 *Fishwt[6]» AND (sus_mass [3]>0)
THEN(can[3] *(NP _mass[ 6] /sus_mass[3]» ELSE
0 )+(IF(F ishwt [4]> (. 3 *Fishwt [6]» AND (sus_mass [4]>0)
THEN (can[ 4] * (NP_mass [ 6 ] /sus_mass[ 4 ] ) } ELSE