APES 5.5-5.6: Meat Production and Overfishing

Concentrated animal feeding operation (CAFO)

An intensive animal feeding operation in which more than 1,000 animal units are confined for over 45 days per year. A CAFO concentrates large quantities of animals and manure in a relatively small area.

Animal unit

A standardized measure equal to 1,000 pounds of live animal weight. Because animals differ in size, the number of animals corresponding to one animal unit varies by species.

How do the same 1,000 animal units compare among different livestock types?

They correspond approximately to 700 dairy cows, 1,000 beef cattle, 2,500 pigs over 55 lb, 10,000 pigs under 55 lb, 10,000 sheep, 55,000 turkeys, 125,000 chickens, or 82,000 laying hens or pullets.

How does the EPA classify CAFOs?

The EPA classifies them as large, medium, or small according to animal capacity, with thresholds that depend on the species and manure-handling system.

What are the EPA size thresholds for cattle and mature dairy cattle?

Large CAFOs have at least 1,000 cattle or 700 mature dairy cattle. Medium facilities have 300–999 cattle or 200–699 mature dairy cattle; smaller facilities fall below those ranges.

What are the EPA size thresholds for swine and turkeys?

For swine over 55 lb, large, medium, and small categories are at least 2,500, 750–2,499, and below 750 animals, respectively. For turkeys, the corresponding thresholds are at least 55,000, 16,500–54,999, and below 16,500.

How does CAFO size affect regulation under the Clean Water Act?

Large CAFOs are automatically subject to EPA regulation. Medium CAFOs must meet a discharge-related criterion or be designated as CAFOs, while small facilities generally require case-by-case designation.

When can a small animal feeding operation become subject to Clean Water Act regulation?

It may be designated a CAFO if it discharges pollutants to U.S. waters through a human-made conveyance such as a pipe, ditch, or road. It may instead remain an ordinary AFO if its waste-management system is properly certified.

Why can the everyday meaning of CAFO differ from its legal meaning?

People commonly use CAFO to describe many large or intensive livestock facilities, including facilities outside the United States or those not legally regulated. The statutory definition under the Clean Water Act is narrower and has changed over time.

Why is manure management a major environmental issue at CAFOs?

CAFOs generate very large quantities of manure in concentrated locations. If storage, treatment, or application fails, nutrients, pathogens, gases, and toxic substances can enter air, soil, surface water, or groundwater.

What major pollutants can be present in CAFO waste?

Important pollutants include soluble nitrogen and phosphorus compounds, organic matter, suspended solids, pathogens, salts, trace elements such as arsenic, antibiotics, pesticides, hormones, and volatile compounds such as ammonia, methane, carbon dioxide, and hydrogen sulfide.

Nutrient pollution

Environmental contamination by excess nitrogen- and phosphorus-containing compounds. In aquatic systems, these nutrients can stimulate excessive biological growth and disrupt dissolved-oxygen conditions.

How can nitrogen and phosphorus from CAFOs cause eutrophication?

Runoff or leakage supplies excess nutrients that promote algal and plant growth. When this biomass dies, microbial decomposition consumes dissolved oxygen, potentially producing hypoxic or anoxic conditions that harm aquatic organisms.

How can CAFO waste reach surface water and groundwater?

Runoff can carry nutrients, organic matter, solids, and pathogens from fields or storage areas into surface waters. Leaching transports dissolved pollutants through soil into groundwater; because surface water and groundwater interact, contamination can move between them.

What is an anaerobic lagoon, and what environmental problems can it create?

An anaerobic lagoon is a manure-storage or wastewater-treatment pond in which microorganisms decompose waste without oxygen. It can reduce some waste-management risks but may also generate methane, hydrogen sulfide, ammonia, odors, and groundwater or surface-water contamination if poorly designed or damaged.

What happened in the 1995 North Carolina CAFO lagoon failure?

A large manure lagoon ruptured and released about 25.8 million U.S. gallons of waste into the New River. The event killed approximately 10 million fish and was associated with human health effects and an outbreak of the microorganism Pfiesteria piscicida.

Which air pollutants are commonly released by CAFOs?

CAFOs can emit ammonia, hydrogen sulfide, methane, carbon dioxide, volatile organic compounds, particulate matter, odors, and airborne antibiotic-resistant bacteria. Emissions generally increase as the amount of stored manure increases.

Why do anaerobic manure-storage systems produce methane and hydrogen sulfide?

In oxygen-poor conditions, microorganisms break down organic matter through anaerobic pathways. Methane is produced during terminal stages of anaerobic decomposition, while sulfur-containing compounds can be reduced to hydrogen sulfide.

What is the major source of livestock-related methane emissions?

Most livestock-related methane comes from enteric fermentation, meaning microbial digestion in the animals' digestive systems. About 17% of livestock-related emissions are attributed to manure, while livestock contribute nearly 30% of anthropogenic methane emissions globally.

What proportion of global greenhouse-gas emissions is associated with livestock production?

Livestock operations account for roughly 18% of global greenhouse-gas emissions and more than 7% of U.S. greenhouse-gas emissions, according to the estimates summarized in the source.

How can CAFO air emissions affect human health?

Ammonia, hydrogen sulfide, particulates, and other pollutants can irritate the eyes and respiratory tract and contribute to asthma, headaches, nausea, chest tightness, and other respiratory problems. Workers and nearby residents may experience the greatest exposure.

How can spray-field waste application affect nearby communities?

Spraying liquid manure onto fields can aerosolize pathogens, heavy metals, irritating gases, and antibiotic-resistant bacteria. Wind may transport these materials toward homes and schools, increasing exposure downwind.

What are production externalities associated with CAFOs?

A negative production externality occurs when a producer's market price does not include harms imposed on others. For CAFOs, these harms can include air and water pollution, greenhouse-gas emissions, antimicrobial resistance, property-value declines, and damage to ecosystems.

Why can CAFO-produced animal products have lower market prices?

Large facilities can lower costs through economies of scale, specialized breeding, mechanization, formulated feed, pharmaceuticals, and efficient contracts. Prices may also appear artificially low when pollution and health costs are shifted to communities rather than paid by producers.

How can antibiotic use in CAFOs promote antimicrobial resistance?

Dense animal populations facilitate pathogen transmission, encouraging antibiotic use for treatment, prevention, and sometimes non-therapeutic growth-related purposes. Antibiotics create selection pressure that favors resistant bacteria, which can spread through animals, workers, wastewater, waste particles, and the environment.

What is the difference between therapeutic and non-therapeutic antibiotic use in animal agriculture?

Therapeutic use treats an identified illness in an animal or group. Non-therapeutic use involves administering antibiotics to prevent infection or improve production when animals are not necessarily sick, a practice criticized for increasing resistance.

How can CAFO contamination affect drinking water and human health?

Pathogens in contaminated surface water or groundwater can cause infectious and gastrointestinal illness, while skin or eye contact can cause irritation or infection. Excess nitrate in drinking water has also been associated with endocrine, metabolic, and nervous-system risks.

Why are CAFO workers at elevated health risk?

Workers have close and prolonged contact with animals, manure, dust, and airborne microorganisms. They may face respiratory inflammation, asthma-like symptoms, injuries, and exposure to zoonotic pathogens or resistant organisms such as livestock-associated MRSA.

What is environmental justice in the context of CAFOs?

Environmental justice concerns arise when low-income or minority communities experience disproportionate exposure to CAFO pollution and have fewer resources or less political influence to oppose facilities or relocate. Falling property values and limited employment alternatives can further trap residents in affected areas.

What are common animal-welfare concerns associated with CAFOs?

Critics argue that crowding, confinement, limited shelter or movement, and prolonged contact with waste can compromise animal welfare. Confinement can also increase disease risk and thereby encourage intensive antibiotic use.

What is the basic Clean Water Act rule governing CAFO discharges?

The Clean Water Act generally prohibits pollutant discharges from a point source into waters of the United States unless authorized by a National Pollutant Discharge Elimination System (NPDES) permit. CAFOs are explicitly classified as point sources.

National Pollutant Discharge Elimination System (NPDES) permit

A permit that authorizes certain pollutant discharges under the Clean Water Act while imposing pollutant limits and management requirements. Compliance with the permit generally provides legal protection against Clean Water Act enforcement for permitted discharges.

Why can an unpermitted CAFO face legal action even for an accidental discharge?

Discharges from a point source are generally prohibited without an NPDES permit, and unauthorized discharges may violate the Clean Water Act even when unplanned or accidental. Permits may include limited defenses for discharges caused by emergencies or natural disasters beyond reasonable control.

Effluent limitations guidelines (ELGs)

EPA requirements that establish pollutant-control standards for an industrial category such as CAFOs. They help determine the numeric discharge limits and management practices incorporated into individual NPDES permits.

Do Clean Water Act technology standards require CAFOs to use one specific technology?

Generally, no. EPA limits are based on the performance of pollution-control technologies, but operators may use alternative methods if those methods effectively meet the required pollutant limits and management standards.

How did the 2003 and 2008 EPA CAFO rules relate to one another?

The 2003 rule revised CAFO effluent and permitting requirements, but a 2005 court decision invalidated portions of it. EPA responded with a revised rule in 2008, including the framework distinguishing automatic, conditional, and case-by-case regulation of large, medium, and small CAFOs.

How has industrial livestock production changed in the United States?

Production has shifted from many smaller farms toward fewer, larger, specialized operations using mechanization, contracting, improved breeding, formulated feeds, and pharmaceuticals. For example, by 2001 roughly 80,000 farms housed as many pigs as about 1 million farms had housed in 1966.

What is overfishing?

Overfishing occurs when fish are harvested faster than populations can reproduce and replace themselves. It reduces population size, disrupts food webs, and can cause fishery collapse.

Why is overfishing a common-resource problem?

Fish in international waters are often a common resource: individuals and nations can access them, but one user's harvest reduces what remains for others. This can encourage excessive harvesting, a form of the tragedy of the commons.

How can overfishing affect marine ecosystems?

Removing large numbers of fish can reduce biodiversity, alter predator–prey relationships, simplify food webs, and cause trophic cascades. The loss of top predators or herbivorous fish can produce especially broad ecosystem changes.

What is bycatch?

Bycatch is the unintended capture of species that are not the target of a fishery, including juvenile fish, sea turtles, seabirds, dolphins, and other marine mammals. Much bycatch is injured or killed and discarded.

How can fishing gear damage marine habitats?

Bottom trawling and some other forms of gear physically disturb seafloor habitats, including coral reefs and benthic communities. This can destroy habitat, resuspend sediments, and reduce the productivity of affected ecosystems.

What practices can make commercial fishing more sustainable?

Sustainable fisheries use science-based catch limits, protected areas, seasonal closures, size limits, selective gear that reduces bycatch, and monitoring and enforcement. Consumers can also favor sustainably certified seafood and lower-trophic-level species.

What is aquaculture?

Aquaculture is the controlled cultivation of aquatic organisms such as fish, shellfish, and algae. It can increase seafood production and reduce pressure on some wild populations, but its environmental effects depend on the species and production system.

What are environmental benefits and drawbacks of aquaculture?

Aquaculture can produce food efficiently and reduce harvesting of wild fish. Potential drawbacks include nutrient and waste pollution, disease and parasite transmission, escape of farmed organisms, habitat loss, and the use of wild-caught fish as feed.

How can aquaculture be made more sustainable?

Impacts can be reduced through careful siting, waste treatment, lower-density systems, disease prevention without excessive antibiotics, prevention of escapes, use of plant-based or efficiently sourced feed, and integrated systems that recycle nutrients.

What is surface mining?

Surface mining removes soil and rock above a mineral deposit to expose and extract the resource. Major forms include strip mining, open-pit mining, and mountaintop-removal mining.

What is subsurface mining?

Subsurface mining extracts minerals through underground shafts, tunnels, or room-and-pillar workings when deposits are too deep for economical surface removal. It generally disturbs less surface area than surface mining but can be more dangerous and costly.

What are the major environmental impacts of surface mining?

Surface mining can remove vegetation and topsoil, fragment or destroy habitats, increase erosion and sedimentation, alter drainage, pollute water, produce dust and noise, and leave large waste piles or pits.

What is mountaintop-removal mining?

Mountaintop removal is a form of surface mining in which explosives remove the summit or ridge above a coal seam. The overburden is commonly placed in nearby valleys, burying streams and destroying forests and habitat.

What is acid mine drainage?

Acid mine drainage forms when sulfide minerals exposed by mining react with oxygen and water, producing sulfuric acid. The acidic water can dissolve and transport toxic metals into streams and groundwater.

What are tailings and why are they an environmental hazard?

Tailings are finely crushed waste materials left after valuable minerals are separated from ore. They may contain toxic metals or processing chemicals, and failures of tailings ponds can release contaminants into surrounding ecosystems.

How can mining pollute water?

Mining can release sediment, acid mine drainage, dissolved metals, processing chemicals, and nutrients into surface water and groundwater. These pollutants can reduce water quality, harm aquatic organisms, and make water unsafe for human use.

How can mining affect land and ecosystems?

Mining removes or buries soil, vegetation, and habitat; fragments landscapes; increases erosion; and may cause subsidence. Mining infrastructure can also displace wildlife and facilitate additional development.

What is reclamation in mining?

Reclamation is the restoration of land disturbed by mining. It can include backfilling pits, stabilizing waste, replacing topsoil, controlling acid drainage, replanting vegetation, and restoring ecosystems or other productive land uses.

How do surface and subsurface mining differ environmentally?

Surface mining usually causes greater immediate disturbance to land, vegetation, and habitat, whereas subsurface mining leaves less surface disturbance but can cause mine subsidence, groundwater contamination, acid drainage, and hazardous working conditions.