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17. An Age-structured Model of Fish Population Enhancement
INTO_YEAR_CLASS[AGE_7_TO_8] =
OUT_OF_YEAR_CLASS[AGE_6_TO_7]+TO_MATURE*0
INTO_YEAR_CLASS[AGE_8_TO_9] =
OUT_OF_YEAR_CLASS[AGE_7_TO_8]+TO_MATURE*0
INTO_YEAR_CLASS[AGE_9_TO_10] =
OUT_OF_YEAR_CLASS[AGE_8_TO_9]+TO_MATURE*0
INTO_YEAR_CLASS[AGE_10_PLUS] =
OUT_OF_YEAR_CLASS[AGE_9_TO_10]+TO_MATURE*0
OUTFLOWS:
CATCH [Year_Class] = MATURE_FISH [Year_Class] *CATCH_RATE
DIE_MATURES [Year_Class] =
MATURE_FISH [Year_Class] *MORT_MATURES [Year_Class]
EMIGRATION [Year_Class] =
MATURE_FISH [Year_Class] *EMIGRATION_RATE
OUT_OF_YEAR_CLASS[Year_Class] =
MATURE_FISH[Year_Class]-CATCH[Year_Class] -
DIE_MATURES [Year_Class]-EMIGRATION[Year_Class]
NAT_AGE_O(t) = NAT_AGE_O(t-dt) + (TO_NAT_AGE_OTO_AGE_l-DIE_AGE_O) * dt
INIT NAT_AGE_O = °
INFLOWS :
TO_NAT_AGE_O = LIVE EGGS -DIE EGGS
OUTFLOWS:
TO_AGE_l = NAT_AGE_O-DIE_AGE_O
DIE_AGE_O = NAT_AGE_O*MORT_AGE_O
NAT_AGE_l(t) = NAT_AGE_l(t-dt) + (TO_AGE_l* dt
DIE_NAT_AGE_l-NAT_TO_JUV_2)
INIT NAT_AGE_l = °
INFLOWS:
TO_AGE_l = NAT AGE O-DIE AGE °
OUTFLOWS:
DIE_NAT_AGE_l = NAT_AGE_l*MORT_AGE 1
NAT_TO_JUV_2 = NAT_AGE_l-DIE_NAT_AGE_l
CATCH_RATE = .60
CATCH_WEIGHT [AGE_3_TO_4] =
CATCH[AGE_3_TO_4]*WEIGHT_AT_AGE[AGE_3_TO_4]
CATCH_WEIGHT [AGE_4_TO_5] =
CATCH[AGE_4_TO_5]*WEIGHT_AT_AGE[AGE_4_TO_5]
CATCH_WEIGHT [AGE_5_TO_6] =
CATCH[AGE_5_TO_6]*WEIGHT_AT_AGE[AGE_5_TO_6]