Sustainability and the sustainable yield

Sustainability means:

• Living  with the means of nature, on the "interest" or sustainable natural income generated by natural capital.
• However, economists and environmentalists may have very different views on what is sustainable.
• Any society that supports itself in part by depleting essential forms of natural capital is unsustainable.

Sustainable yield is the increase in natural capital. Natural income that can be exploited. It's important to know some factors:

• Carrying capacity
• Population size
• Total biomass or energy at a given time
• Rates of change of population, biomass and energy

Two formulas for calculating sustainable yield are

• (total biomass or energy at time t+1) - (total biomass or energy at time t)
• (Annual growth and recruitment) - (Annual deaths and emigration).