High-Density Animal Farming
Concentrated animal feeding operations (CAFOs) - large indoor or outdoor structures designed for maximum output; aka feedlots
Free-range animal farming - when animals are raised by allowing them to graze or feed on the natural productivity of land, with little or no supplemental feeding
- Used for beef cattle, dairy cows, hogs, and poultry, all of which are confined or allowed very little room for movement during all or part of their life cycle
- Farmers minimize land costs, improve feeding efficiency, and increase the fraction of food energy that goes into the production of animal body mass
- Animals are given antibiotics and nutrient supplements to reduce the risk of adverse health effects and diseases
- Downside = increases antibiotic-resistant strains of micro-organisms that can effect humans, waste disposal can cause nutrient runoff problems
Free-range animal farming - when animals are raised by allowing them to graze or feed on the natural productivity of land, with little or no supplemental feeding
- More sustainable than CAFOs
- Animals are less likely to spread disease
- Use of antibiotics and other medications are reduced or eliminated
- Less use of fossil fuel
- Manure and urine are dispersed over the range area and are naturally processed by detritivores and decomposers in the soil
- Downside = use more land than CAFOs do, cost of meet produced is significantly higher
Fisheries
Fishery - a commercially harvestable population of fish within a particular ecological region
- Susceptible to tragedy of the commons because fish migrate out of national borders
- Fish in the ocean do not belong to any one individual or nation
- Competition for fish has led to an abrupt decline in fish populations
- Fishery collapse- the decline of a fish population by 90% or more
- Most marine fish are now caught either by large nets pulled behind a factory ship or by very long fishing lines bearing hundreds or even thousands of baited hooks
- Fish species that live on or close to the ocean bottom, as well as many shellfish, are caught in dragnets, which are weighted so that they can be pulled across the ocean floor
- Intensive fishing has lead to the loss of juvenile fish of the target species as well as to the loss of noncommercial species that are accidentally caught by nets and lines
- Bycatch- the unintentional catch of non-target species while fishing
Aquaculture
Aquaculture - the farming of aquatic organisms such as fish, shellfish, and seaweeds
- Involves constructing an aquatic ecosystem by stocking the organisms, feeding them, and protecting them from diseases and predators
- Usually requires keeping the organisms in enclosures and may require providing them with food and antibiotics
- Almost all of the catfish and trout eaten in the U.S., as well as half of the shrimp and salmon, are produced by aquaculture