Welcome to Herrings, a simulation game exploring sustainable management of renewable resources. This page is the instructions; the game itself is available via a link at the bottom.
Find the profit-maximizing level of fishing effort for a sustainable harvest of a search fishery.
Each turn you must decide how much effort to devote to fishing. Enter the value using the Effort slider. When you're happy with your level of effort (!), click the "Next Turn" button to see how things turn out.
Spawn = NatGrow*StartPop*(CarryCap-StartPop)/CarryCap + Shockwhere Spawn is the number of new fish, StartPop is the population at the beginning of the period, and NatGrow and CarryCap are parameters representing fish biology. Shock is an annual disturbance drawn from a normal distribution with mean zero and unknown variance. The population at the end of the period will be given by:
EndPop = StartPop + Spawn - Harvestwhere Harvest is the number of fish harvested by people (more on that below). This will become the starting population for the next period. (Just to make sure there aren't any ambiguities please note that Spawn, Harvest, EndPop and StartPop may vary with time while NatGrow and CarryCap do not.)
Harvest = Tech*StartPop*(Effort/100)where Harvest is the number of fish caught, Tech is a parameter (initially unknown), and Effort is the level of effort. (The factor of 100 appears here for computer convenience rather than economics: it allows a slider on the game to read from 0 to 100 instead of from 0 to 1.) Finally, the fishery is a price-taker in both the fish and labor markets. Its total revenue and total cost are given by:
Revenue = $1*Harvest
Cost = $2000*(Effort/100)