When food is formed under water. Starting with algae and photosynthesis moving up to bigger fish that we eat.
When land is cleared for timber and such and Animals that once lived there will move into the remainig forest.
Optimum Sustainable Population
A population that will provide the most benefit whether it be economically or ecologically. Results in optimum sustainable yeild.
When the items being farmed are used directly by those who farm it or go short distances to near by markets. In fish situation, Fish are not getting caught in large amounts and shipped out across the nation.