Transcript Drift Net = a large (40 miles long)

Chapter 19
Food Resources: A Challenge For
Agriculture
Overview of Chapter 19
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Food and Nutrition
World Food Problems
Principle Types of Agriculture
Challenges of Producing More Crops and
Livestock
Environmental Impact of Agriculture
Solutions to Agricultural Problems
Fisheries of the World
Food and Nutrition
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Carbohydrates
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Proteins
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Large, complex molecules composed of amino
acids that perform critical roles in body
Lipids
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Sugars and starches metabolized by cellular
respiration to produce energy
Include fats and oils and are metabolized by
cellular respiration to produce energy
Vitamins and Minerals
Human Foods
World Food Problems
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Feeding growing population is difficult
Annual grain production (left) has increased
since 1970
Grain per person has not (right)
World Food Problems
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Famine
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Failure of crops caused by drought, flood or
catastrophic event
Temporary but severe shortage of food
Maintaining World Grain Carryover
Stockpiles
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Amounts of rice, wheat, corn and other grains
remaining from previous harvest
Provides measure of food security
Decreased each year since 1987
UN feels carryover stock should not fall below
70 days
World Grain
Carryover Stock
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Why the decline?
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Rising temperatures
Falling water tables
and droughts
Ethanol production
More grain is going
towards feeding
livestock
World Food Problems
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Poverty and Food
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1.3 billion people are so poor they cannot
afford proper nutrition
More common in
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Rural than urban areas
Infants, children and the elderly
Economics and Politics
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Cost money to store, produce, transport and
distribute food
Getting food to those who need it is political
Principle Types of Agriculture
Industrialized
agriculture
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Modern
agriculture
methods
that require
large capital
input, and
less land and
labor
Principle Types of Agriculture
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Subsistence Agriculture
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Traditional agricultural methods, which are
dependent on labor and large amounts of land
Examples:
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Shifting cultivation
Slash and burn agriculture
Nomadic herding
Intercropping
Challenges of Producing More Crop and
Livestock
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Domestication and Genetic Diversity
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Domestication of crops and livestock causes a loss of
genetic diversity
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Farmer selects and propagates animals with desirable
agricultural characteristics
Many high yielding
crops are genetically
uniform
High likelihood that
bacteria, fungi, viruses,
etc. will attack and
destroy entire crop
Challenges of Producing More Crop and
Livestock
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Increasing Crop Yield
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Food production
increased in
developed
countries (wheat
(left)
Pesticides
Selective
breeding
Case-In-Point Green Revolution
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High Yielding Rice Varieties
Challenges of Producing More Crop and
Livestock
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Increasing Livestock Yields
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Hormone supplements
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US and Canada do this
Europe does not citing human health concerns
Antibiotics
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40% of antibiotics produced in US are used in livestock
operations
Problems with increased bacteria resistance
Antibiotic Use and Resistance
Genetic Engineering
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Manipulation of genes by taking specific gene from a cell of
one species and placing it into the cell of an unrelated species
Issue with Genetically Modified Organisms
(GMOs)
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Determined to be safe for human consumption
(according to current research)
Concerns about GMO seed or pollen spreading in
wild
Backlash against GMOs
GMOs are not currently labeled
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FDA finds it would be counterproductive and
expensive to label
Environmental Impacts of Agriculture
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High use of fossil fuels and
pesticides
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Untreated animal wastes and
agricultural chemicals
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Air pollution
Water pollution
Harms fisheries
Insects, weeds, and diseasecausing organisms developing
resistance to pesticides
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Contaminate food supply
Environmental Impact of Agriculture
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Land degradation
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Habitat fragmentation
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Decreases future ability of land to support crops or
livestock
Breakup of large areas of habitat into small, isolated
patches
Cultivating marginal lands
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Irrigating dry land
Cultivating land prone to erosion
Solutions to Agricultural ProblemsSustainable Agriculture
Sustainable Agriculture
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Examples:
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Natural Predator-prey relationships instead of
pesticides
Crop selection
Crop rotation and conservation tillage
Supplying nitrogen with legumes
Organic agriculture
Integrated Pest Management (IPM)
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Limited use of pesticides with sustainable
agriculture practices
Fisheries of the World- Problems
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No nation lays claim to
open ocean
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Resource susceptible to
overuse and degradation
Overharvesting
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Many species are at point
of severe depletion
Cod (right)
62% of world’s fish stock
are in need of
management action
Fisheries of the World- Problems
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Overharvesting
(continued)
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Sophisticated fishing
equipment
Bycatch (all
unintentionally caught
species) are killed off!
Magnuson Fisheries
Conservation Act
(1977) = established 8
regional fisheries
councils who
established
“management plans”,
but usually set quotas
too high!
Drift Net = a large (40
miles long) net designed to
entangle thousands of fish
Longlines = fishing lines
with thousands of baited and other marine
hooks…up to 80 miles long! organisms…most countries
now ban their use
Trawl net = a
weighted, funnelshaped net pulled
along the bottom of
the ocean to catch
bottom-feeding
fishes (benthic
organisms) and
shrimp…up to 30 tons
of seafood can be
caught in a single
net!
Purse-seine net
= huge nets
(over a mile
wide), that are
set out to
encircle large
schools and then
drawn up and
closed to trap
them
Fisheries of the World- Problems
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Ocean Pollution - dumping ground
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Oil
Heavy metals
Deliberate litter dumping
Stormwater runoff from cities and agricultural areas
Aquaculture
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Growing of aquatic organisms for human consumption
Great potential to supply food
Fisheries of the World- Problems
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Aquaculture (continued)
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Locations of fisheries may hurt natural habitats
Produce waste that pollutes adjacent water
Other Important Marine Legislation:
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Magnuson-Stevens Fishery Conservation and
Management Act (1996) = the regional councils and the
National Marine Fisheries Service must now protect
“essential fish habitat” for more than 600 fish species,
work to reduce overfishing, rebuild threatened
populations, minimize bycatch, etc.
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Must also establish more realistic fishing quotas, restrict
certain fishing gear, limit number of fishing boats, and close
fisheries during spawning periods or times of severe depletion
of fish stocks!
Law was re-authorized in 2007 to strengthen controls over
illegal fishing in U.S. waters.
Other Important Marine Legislation:
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Ocean Dumping Ban Act (1988):
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Barred ocean dumping of sludge and industrial waste,
beginning in 1991…requiring that sanitary landfills be
used instead!
National Marine Sanctuaries Act (1972) –
established several critical habitat areas as
marine sanctuaries, limiting the activities such
as fishing that can take place there!