This model incorporates several options in examining fisheries dynamics and fisheries employment. The two most important aspects are the choice between I)managing based on setting fixed quota versus setting fixed effort , and ii) using the 'scientific advice' for quota setting  versus allowing 'political influence' on quota setting (the assumption here is that you have good estimates of recruitment and stock assessments that form the basis of 'scientific advice' and then 'political influnce' that desires increased quota beyond the scientific advice).

Fig 3.1 from Jorgen Randers book 2052 a Global Forecast for the Next Forty Years

This simple model will attempt to demonstrate how modern civilization's groundwater practices are unsustainable and how they are affected by the changing climate.

Perspective on Sustainability, Environment, and Development