18.6. Quest ions and Tasks
415
OUTFLOWS:
obsolescing = Vessels /avg_life_span_of_vessel
Vessels_on_Order(t) = Vessels_on_Order(t-dt) +
(ordering_vessels-receiving_vessels) * dt
INIT Vessels_on_Order = 2400
INFLOWS :
ordering_vessels
((Profit_fisheries*percent_to_reinvest_fisheries)) /cost
-per_new_vessel
OUTFLOWS :
receiving_vessels
Vessels_on_Order /time_to_receive_vessels
wild_Shrimp_Biomass(t) = Wild_Shrimp_Biomass(t-dt) +
(adding_to_biomass-losing_biomass-catching) * dt
INIT Wild_Shrimp_Biomass =
unfished_biomass_k*biomass_k-pct
INFLOWS :
adding_to_biomass
Wild_Shrimp_Biomass*rate_of_biomass_growth
OUTFLOWS:
losing_biomass =
Wild_Shrimp_Biomass*rate_of_biomass_growth*impact_of_B\
k*effect_of_coastal_eff_on_wild
catching = Vessels*actual_catch-per_vessel
actual_catch-per_vessel =
normal_catch-per_vessel* impact_of_B \k_on_catch
avg_life_span_of_vessel =
250*impact_of_catch-per_vessel
biomass_k-pct = .5
biomass_to_unfished_biomass_k =
Wild_Shrimp_Biomass /unfished_biomass_k
cost-per_new_vessel = 40000
fisheries_market_share = catching /(catching+harvesting)
funds_from_subsidy =
vessel_subsidy_amount*subsidy_on_shrimp_vessels
normal_catch-per_vessel = 3500
percent_to_reinvest_fisheries =
0 .1006289308176*imp_of_cov_and-price_on_invest
rate_of_biomass_growth = . 1
subsidy_on_shrimp_vessels
0
time_to_receive_vessels = 6