Aquaculture: Aquatic Feedlots Raising large numbers of fish and shellfish in ponds and cages is world’s fastest growing type of food production. Fish

Aquaculture: Aquatic FeedlotsAquaculture: Aquatic Feedlots

Raising large numbers of fish and shellfish in Raising large numbers of fish and shellfish in ponds and cages is world’s fastest growing ponds and cages is world’s fastest growing type of food production.type of food production.

Fish farming involves cultivating fish in a Fish farming involves cultivating fish in a controlled environment and harvesting them controlled environment and harvesting them in captivity.in captivity.

Fish ranching involves holding anadromous Fish ranching involves holding anadromous species that live part of their lives in species that live part of their lives in freshwater and part in saltwater.freshwater and part in saltwater. Fish are held for the first few years, released, Fish are held for the first few years, released,

and then harvested when they return to spawn.and then harvested when they return to spawn.

Fig. 13-24, p. 292

Trade-Offs

Aquaculture

Advantages Disadvantages

High efficiency Needs large inputs of land, feed, and water

High yield in small volume of water

Large waste output

Destroys mangrove forests and estuaries

Can reduce overharvesting of conventional fisheries Uses grain to feed

some species

Low fuel use Dense populations vulnerable to disease

Tanks too contaminated to use after about 5 years

High profits

Profits not tied to price of oil

Fig. 13-25, p. 293

Solutions

More Sustainable Aquaculture

• Use less fishmeal feed to reduce depletion of other fish

• Improve management of aquaculture wastes

• Reduce escape of aquaculture species into the wild

• Restrict location of fish farms to reduce loss of mangrove forests and estuaries

• Farm some aquaculture species in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean

• Certify sustainable forms of aquaculture

How Would You Vote?How Would You Vote?

To conduct an instant in-class survey using a classroom response To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment.menu for Living in the Environment.

Do the advantages of aquaculture outweigh Do the advantages of aquaculture outweigh its disadvantages?its disadvantages? a. No. Although there are advantages, a. No. Although there are advantages,

aquaculture causes significant environmental aquaculture causes significant environmental damage.damage.

b. Yes. Aquaculture can protect wild marine b. Yes. Aquaculture can protect wild marine species from commercial extinction. species from commercial extinction.

SOLUTIONS: MOVING TOWARD SOLUTIONS: MOVING TOWARD GLOBAL FOOD SECURITYGLOBAL FOOD SECURITY

People in urban areas People in urban areas could save money by could save money by growing more of their growing more of their food.food. Urban gardens provide Urban gardens provide

about 15% of the about 15% of the world’s food supply.world’s food supply.

Up to 90% of the Up to 90% of the world’s food is wasted.world’s food is wasted.

Figure 13-26Figure 13-26

Government Policies and Food Government Policies and Food ProductionProduction

Governments use three main approaches to Governments use three main approaches to influence food production:influence food production: Control pricesControl prices to keep prices artificially low. to keep prices artificially low. Provide subsidiesProvide subsidies to keep farmers in business. to keep farmers in business. Let the marketplace decideLet the marketplace decide rather that rather that

implementing price controls.implementing price controls.



Should governments phase out subsidies for Should governments phase out subsidies for conventional industrialized agriculture and phase in conventional industrialized agriculture and phase in subsidies for more sustainable agriculture?subsidies for more sustainable agriculture? a. No. Current subsidies maintain critical food a. No. Current subsidies maintain critical food

supplies that should not be disrupted to Americans supplies that should not be disrupted to Americans and others.and others.

b. Yes. Agricultural pollution is a serious problem and b. Yes. Agricultural pollution is a serious problem and subsidies should be used to encourage subsidies should be used to encourage environmentally friendly agriculture.environmentally friendly agriculture.

Solutions: Steps Toward More Solutions: Steps Toward More Sustainable Food ProductionSustainable Food Production

We can increase food security by slowing We can increase food security by slowing populations growth, sharply reducing poverty, populations growth, sharply reducing poverty, and slowing environmental degradation of the and slowing environmental degradation of the world’s soils and croplands.world’s soils and croplands.

PROTECTING FOOD RESOURCES: PROTECTING FOOD RESOURCES: PEST MANAGEMENTPEST MANAGEMENT

Organisms found in Organisms found in nature (such as nature (such as spiders) control spiders) control populations of most populations of most pest species as part pest species as part of the earth’s free of the earth’s free ecological services.ecological services.



We use chemicals to repel or kill pest We use chemicals to repel or kill pest organisms as plants have done for millions of organisms as plants have done for millions of years.years.

Chemists have developed hundreds of Chemists have developed hundreds of chemicals (pesticides) that can kill or repel chemicals (pesticides) that can kill or repel pests.pests. Pesticides vary in their persistence.Pesticides vary in their persistence. Each year > 250,000 people in the U.S. become Each year > 250,000 people in the U.S. become

ill from household pesticides.ill from household pesticides.

Animation: Pesticide ExamplesAnimation: Pesticide Examples

PLAYANIMATION


Advantages and disadvantages of conventional Advantages and disadvantages of conventional chemical pesticides.chemical pesticides.


Fig. 13-28, p. 295

Advantages Disadvantages

Save lives Promote genetic resistance

Increase food supplies Kill natural pest enemies

Profitable to use Create new pest species

Work fast Pollute the environment

Safe if used properly

Can harm wildlife and people

Individuals Matter: Rachel CarsonIndividuals Matter: Rachel Carson

Wrote Wrote Silent SpringSilent Spring which introduced the which introduced the U.S. to the dangers U.S. to the dangers of the pesticide DDT of the pesticide DDT and related and related compounds to the compounds to the environment.environment.

Figure 13-AFigure 13-A

The ideal Pesticide and the The ideal Pesticide and the Nightmare Insect PestNightmare Insect Pest

The ideal pest-killing chemical has these The ideal pest-killing chemical has these qualities:qualities: Kill only target pest.Kill only target pest. Not cause genetic resistance in the target Not cause genetic resistance in the target

organism.organism. Disappear or break down into harmless Disappear or break down into harmless

chemicals after doing its job.chemicals after doing its job. Be more cost-effective than doing nothing.Be more cost-effective than doing nothing.

SuperpestsSuperpests

Superpests are Superpests are resistant to resistant to pesticides.pesticides.

Superpests like the Superpests like the silver whiteflysilver whitefly (left) (left) challenge farmers challenge farmers as they cause > as they cause > $200 million per $200 million per year in U.S. crop year in U.S. crop losses.losses.


Pesticide Protection Laws in the U.S.Pesticide Protection Laws in the U.S.

Government regulation has banned a number Government regulation has banned a number of harmful pesticides but some scientists call of harmful pesticides but some scientists call for strengthening pesticide laws.for strengthening pesticide laws. The Environmental Protection Agency (EPA), the The Environmental Protection Agency (EPA), the

Department of Agriculture (USDA), and the Food Department of Agriculture (USDA), and the Food and Drug Administration (FDA) regulate the sales and Drug Administration (FDA) regulate the sales of pesticides under the Federal Insecticide, of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).Fungicide and Rodenticide Act (FIFRA).

The EPA has only evaluated the health effects of The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides.10% of the active ingredients of all pesticides.



Do the advantages of using synthetic Do the advantages of using synthetic chemical pesticides outweigh their chemical pesticides outweigh their disadvantages? disadvantages? a. No. Synthetic pesticides are overused, a. No. Synthetic pesticides are overused,

damage the environment, and increase cancer damage the environment, and increase cancer risks.risks.

b. Yes. Pesticides save human lives and protect b. Yes. Pesticides save human lives and protect crops. crops.

Fig. 13-30, p. 299

What Can You Do?

Reducing Exposure to Pesticides

• Grow some of your food using organic methods.

• Buy organic food.

• Wash and scrub all fresh fruits, vegetables, and wild foods you pick.

• Eat less or no meat.

• Trim the fat from meat.

Other Ways to Control PestsOther Ways to Control Pests

There are cultivation, biological, and There are cultivation, biological, and ecological alternatives to conventional ecological alternatives to conventional chemical pesticides.chemical pesticides. Fool the pest through cultivation practices.Fool the pest through cultivation practices. Provide homes for the pest enemies.Provide homes for the pest enemies. Implant genetic resistance.Implant genetic resistance. Bring in natural enemies.Bring in natural enemies. Use pheromones to lure pests into traps.Use pheromones to lure pests into traps. Use hormones to disrupt life cycles.Use hormones to disrupt life cycles.


Biological pest Biological pest controlcontrol: Wasp : Wasp parasitizing a parasitizing a gypsy moth gypsy moth caterpillar.caterpillar.



Genetic Genetic engineering can engineering can be used to be used to develop pest and develop pest and disease resistant disease resistant crop strains.crop strains.

Both tomato plants were exposed to Both tomato plants were exposed to destructive caterpillars. The genetically destructive caterpillars. The genetically altered plant (right) shows little damage.altered plant (right) shows little damage.


Case Study: integrated Pest Case Study: integrated Pest Management: A Component of Management: A Component of

Sustainable AgricultureSustainable Agriculture

An ecological approach to pest control uses a An ecological approach to pest control uses a mix of cultivation and biological methods, and mix of cultivation and biological methods, and small amounts of selected chemical small amounts of selected chemical pesticides as a last resort.pesticides as a last resort. Integrated Pest Management (IPM)Integrated Pest Management (IPM)

Case Study: integrated Pest Case Study: integrated Pest Management: A Component of Management: A Component of

Sustainable AgricultureSustainable Agriculture Many scientists urge the USDA to use three Many scientists urge the USDA to use three

strategies to promote IPM in the U.S.:strategies to promote IPM in the U.S.: Add a 2% sales tax on pesticides.Add a 2% sales tax on pesticides. Establish federally supported IPM demonstration Establish federally supported IPM demonstration

project for farmers.project for farmers. Train USDA personnel and county farm agents in Train USDA personnel and county farm agents in

IPM.IPM. The pesticide industry opposes such The pesticide industry opposes such

measures.measures.



Should governments heavily subsidize a Should governments heavily subsidize a switch to integrated pest management? switch to integrated pest management? a. No. Without extensive funding and training, a. No. Without extensive funding and training,

mere subsidies are not enough to successfully mere subsidies are not enough to successfully promote integrated pest management.promote integrated pest management.

b. Yes. These subsidies would decrease pollution b. Yes. These subsidies would decrease pollution and exposure to hazardous pesticides. and exposure to hazardous pesticides.

SOLUTIONS: SUSTAINABLE SOLUTIONS: SUSTAINABLE AGRICULTUREAGRICULTURE

Three main ways to reduce hunger and Three main ways to reduce hunger and malnutrition and the harmful effects of malnutrition and the harmful effects of agriculture:agriculture: Slow population growth.Slow population growth. Sharply reduce poverty.Sharply reduce poverty. Develop and phase in systems of more Develop and phase in systems of more

sustainable, low input agriculture over the next sustainable, low input agriculture over the next few decades.few decades.

Fig. 13-33, p. 302

Solutions

Sustainable Organic Agriculture

More Less

High-yield polyculture

Soil erosion

Soil salinizationOrganic fertilizers

Aquifer depletionBiological pest control Overgrazing

Integrated pest management

Overfishing

Loss of biodiversity

Efficient irrigation Loss of prime

croplandPerennial crops

Crop rotationFood waste

Water-efficient crops

Subsidies for unsustainable farming and fishing

Soil conservation

Subsidies for sustainable farming and fishing

Population growth

Poverty

Sustainable Sustainable AgricultureAgriculture

Results of 22 Results of 22 year study year study comparing comparing organic and organic and conventional conventional farming.farming.


Fig. 13-34, p. 302

Solutions

Organic Farming

Improves soil fertility

Reduces soil erosion

Retains more water in soil during drought years

Uses about 30% less energy per unit of yield

Lowers CO2 emissions

Reduces water pollution from recycling livestock wastes

Eliminates pollution from pesticides

Increases biodiversity above and below ground

Benefits wildlife such as birds and bats

Solutions: Making the Transition to Solutions: Making the Transition to More Sustainable AgricultureMore Sustainable Agriculture

More research, More research, demonstration demonstration projects, projects, government government subsidies, and subsidies, and training can training can promote more promote more sustainable sustainable organic organic agriculture.agriculture.


Fig. 13-35, p. 303

What Can You Do?

Sustainable Organic Agriculture

• Waste less food

• Eat less or no meat

• Feed pets balanced grain foods instead of meat

• Use organic farming to grow some of your food

• Buy organic food

• Eat locally grown food

• Compost food wastes

Documents

Aquaculture: Aquatic Feedlots Raising large numbers of fish and shellfish in ponds and cages is world’s fastest growing type of food production. Fish