3750fish_birthsfish_deathsfish_catchbirth_rate*Fishdeath_rate*Fishdensity_effect_on_birth_rate*normal_birth_ratedensity_effect_on_death_rate*normal_death_rate5000Fish/carrying_capacitycatch_per_ship*Ships_At_Sea25As density increases, so does fish catch. This is ostensibly a exponential approach to a limit, but it is a little deformed near zero as it drops near and then smoothly approaches zero from a positive non-zero value.fish_density0,0.10000000000000001,0.20000000000000001,0.30000000000000004,0.40000000000000002,0.5,0.59999999999999998,0.69999999999999996,0.79999999999999993,0.89999999999999991,0.999999999999999890,0.14999999999999999,0.61499999999999999,0.70000000000000007,0.755,0.80500000000000005,0.87,0.92500000000000004,0.96999999999999997,1,1density_effect_on_catch_per_ship*catch_per_ship_normal30new_shipsbuying_pattern_for_ships
{ preprogrammed sequence of ship buying decisions - user should make these decisions based on Cash and/or fish catch }30010There are two additional expenses that are not modeled: The maintanence cost of an idle ship (all ships are fishing in this model) and the cost of any interest on a loan for a negative cash balance (earning interest on a positive balance is also not modeled).cost_of_new_ships + maintenance_cost0revenuesexpensesprice_per_fish*fish_catch30price_per_ship*new_shipsmaintenance_cost_per_ship*Ships_At_Sea(fish_births - fish_deaths)/FishA density increases, so does the birth rate. This happens faster than the death rate making regeneration higher at a moderate density than at either extreme.fish_density0,0.10000000000000001,0.20000000000000001,0.30000000000000004,0.40000000000000002,0.5,0.59999999999999998,0.69999999999999996,0.79999999999999993,0.89999999999999991,0.999999999999999890,0.435,0.63500000000000001,0.76000000000000001,0.85999999999999999,0.93000000000000005,0.97999999999999998,1,1,1,10.20.1Death rate increase moderately with density until the fishery becomes quite crowded. Then it increases quite quickly.fish_density0,0.10000000000000001,0.20000000000000001,0.30000000000000004,0.40000000000000002,0.5,0.59999999999999998,0.69999999999999996,0.79999999999999993,0.89999999999999991,0.999999999999999890,0.029999999999999999,0.059999999999999998,0.10000000000000001,0.14000000000000001,0.22,0.31,0.45000000000000001,0.78000000000000003,1.8500000000000001,2Cash + salvage_value_per_ship*Ships_At_Sea100TIME30,20,20,10,5,0,0Fishfish_birthsFishfish_deathsbirth_ratefish_birthscarrying_capacityfish_densityfish_densitydensity_effect_on_death_ratedeath_ratefish_deathsFishfish_densityfish_densitydensity_effect_on_catch_per_shipcatch_per_shipfish_catchdensity_effect_on_catch_per_shipcatch_per_shipcatch_per_ship_normalcatch_per_shipShips_At_Seafish_catchfish_catchrevenuesprice_per_fishrevenuesnew_shipscost_of_new_shipscost_of_new_shipsexpensesmaintenance_cost_per_shipmaintenance_costShips_At_Seamaintenance_costmaintenance_costexpensesprice_per_shipcost_of_new_shipsfish_birthsregeneration_ratefish_deathsregeneration_rateFishregeneration_ratefish_densitydensity_effect_on_birth_ratedensity_effect_on_birth_ratebirth_ratenormal_birth_ratebirth_ratedensity_effect_on_death_ratedeath_ratenormal_death_ratedeath_rateCashAssetsbottomShips_At_SeaAssetssalvage_value_per_shipAssetsbuying_pattern_for_shipsnew_ships0.4