A simple bieconomic model (the Gordon-SChaefer model) is estimated for three species of tuna in the Eastern Tropical Atlantic. The model conformed well to the data and afforded estimates of maximum sustainable yield, bioeconomic and open access equilibria. Strong marginal stock effects were...

Water quality and other environmental issues are often viewed as threats by farm managers. Farm managers also pride 'themselves as good stewards of the land. Assisting managers in developing their mission statement including an environment component can reduce the conflict between farm managers...