Aquaculture: Aquatic Feedlots

1
Aquaculture Aquatic Feedlots

• Raising large numbers of fish and shellfish in
  ponds and cages is worlds fastest growing type
  of food production.
• Fish farming involves cultivating fish in a
  controlled environment and harvesting them in
  captivity.
• Fish ranching involves holding anadromous species
  that live part of their lives in freshwater and
  part in saltwater.
• Fish are held for the first few years, released,
  and then harvested when they return to spawn.

2

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
High profits
Tanks too contaminated to use after about 5 years
Profits not tied to price of oil
Fig. 13-24, p. 292
3

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
Fig. 13-25, p. 293
4
How Would You Vote?

• To conduct an instant in-class survey using a
  classroom response system, access JoinIn Clicker
  Content from the PowerLecture main menu for
  Living in the Environment.
• Do the advantages of aquaculture outweigh its
  disadvantages?
• a. No. Although there are advantages, aquaculture
  causes significant environmental damage.
• b. Yes. Aquaculture can protect wild marine
  species from commercial extinction.

5
SOLUTIONS MOVING TOWARD GLOBAL FOOD SECURITY

• People in urban areas could save money by growing
  more of their food.
• Urban gardens provide about 15 of the worlds
  food supply.
• Up to 90 of the worlds food is wasted.

Figure 13-26
6
Government Policies and Food Production

• Governments use three main approaches to
  influence food production
• Control prices to keep prices artificially low.
• Provide subsidies to keep farmers in business.
• Let the marketplace decide rather that
  implementing price controls.

7
How Would You Vote?

• To conduct an instant in-class survey using a
  classroom response system, access JoinIn Clicker
  Content from the PowerLecture main menu for
  Living in the Environment.
• Should governments phase out subsidies for
  conventional industrialized agriculture and phase
  in subsidies for more sustainable agriculture?
• a. No. Current subsidies maintain critical food
  supplies that should not be disrupted to
  Americans and others.
• b. Yes. Agricultural pollution is a serious
  problem and subsidies should be used to encourage
  environmentally friendly agriculture.

8
Solutions Steps Toward More Sustainable Food
Production

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

9
PROTECTING FOOD RESOURCES PEST MANAGEMENT

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

Figure 13-27
10
PROTECTING FOOD RESOURCES PEST MANAGEMENT

• We use chemicals to repel or kill pest organisms
  as plants have done for millions of years.
• Chemists have developed hundreds of chemicals
  (pesticides) that can kill or repel pests.
• Pesticides vary in their persistence.
• Each year gt 250,000 people in the U.S. become ill
  from household pesticides.

11
Animation Pesticide Examples
PLAY ANIMATION
12
PROTECTING FOOD RESOURCES PEST MANAGEMENT

• Advantages and disadvantages of conventional
  chemical pesticides.

Figure 13-28
13

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
Fig. 13-28, p. 295
14
Individuals Matter Rachel Carson

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

Figure 13-A
15
The ideal Pesticide and the Nightmare Insect Pest

• The ideal pest-killing chemical has these
  qualities
• Kill only target pest.
• Not cause genetic resistance in the target
  organism.
• Disappear or break down into harmless chemicals
  after doing its job.
• Be more cost-effective than doing nothing.

16
Superpests

• Superpests are resistant to pesticides.
• Superpests like the silver whitefly (left)
  challenge farmers as they cause gt 200 million
  per year in U.S. crop losses.

Figure 13-29
17
Pesticide Protection Laws in the U.S.

• Government regulation has banned a number of
  harmful pesticides but some scientists call for
  strengthening pesticide laws.
• The Environmental Protection Agency (EPA), the
  Department of Agriculture (USDA), and the Food
  and Drug Administration (FDA) regulate the sales
  of pesticides under the Federal Insecticide,
  Fungicide and Rodenticide Act (FIFRA).
• The EPA has only evaluated the health effects of
  10 of the active ingredients of all pesticides.

18
How Would You Vote?

• To conduct an instant in-class survey using a
  classroom response system, access JoinIn Clicker
  Content from the PowerLecture main menu for
  Living in the Environment.
• Do the advantages of using synthetic chemical
  pesticides outweigh their disadvantages?
• a. No. Synthetic pesticides are overused, damage
  the environment, and increase cancer risks.
• b. Yes. Pesticides save human lives and protect
  crops.

19

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.
Fig. 13-30, p. 299
20
Other Ways to Control Pests

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

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Other Ways to Control Pests

• Biological pest control Wasp parasitizing a
  gypsy moth caterpillar.

Figure 13-31
22
Other Ways to Control Pests

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

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

Figure 13-32
23
Case Study integrated Pest Management A
Component of Sustainable Agriculture

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

24
Case Study integrated Pest Management A
Component of Sustainable Agriculture

• Many scientists urge the USDA to use three
  strategies to promote IPM in the U.S.
• Add a 2 sales tax on pesticides.
• Establish federally supported IPM demonstration
  project for farmers.
• Train USDA personnel and county farm agents in
  IPM.
• The pesticide industry opposes such measures.

25
How Would You Vote?

• To conduct an instant in-class survey using a
  classroom response system, access JoinIn Clicker
  Content from the PowerLecture main menu for
  Living in the Environment.
• Should governments heavily subsidize a switch to
  integrated pest management?
• a. No. Without extensive funding and training,
  mere subsidies are not enough to successfully
  promote integrated pest management.
• b. Yes. These subsidies would decrease pollution
  and exposure to hazardous pesticides.

26
SOLUTIONS SUSTAINABLE AGRICULTURE

• Three main ways to reduce hunger and malnutrition
  and the harmful effects of agriculture
• Slow population growth.
• Sharply reduce poverty.
• Develop and phase in systems of more sustainable,
  low input agriculture over the next few decades.

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Solutions
Sustainable Organic Agriculture
More
Less
High-yield polyculture
Soil erosion
Soil salinization
Organic fertilizers
Aquifer depletion
Biological pest control
Overgrazing
Overfishing
Integrated pest management
Loss of biodiversity
Efficient irrigation
Loss of prime cropland
Perennial crops
Food waste
Crop rotation
Subsidies for unsustainable farming and fishing
Water-efficient crops
Soil conservation
Population growth
Subsidies for sustainable farming and fishing
Poverty
Fig. 13-33, p. 302
28
Sustainable Agriculture

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

Figure 13-34
29

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
Fig. 13-34, p. 302
30
Solutions Making the Transition to More
Sustainable Agriculture

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

Figure 13-35
31

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
Fig. 13-35, p. 303