1. Resources

2. What are Resources?
Resource- An available supply that can be drawn on when needed
Humans are most consistently impacting their environment through their quest for resources.
The types of resources are limitless, but can basically be defined as an environmental factor that is desirable to somebody.
Basically if there is somebody who wants something, we can consider it a resource

3. When resources are freely available
The Tragedy of the Commons- Garrett Hardin (1968)
“commons” – any freely available resource shared by a group of people
Ex. Fish, forests, clean air, water, pasture land, etc.
Hardin believed that people are greedy and will act in their own short-sighted self-interest, depleting resources until the “commons” collapses
Each person attempts to maximize their portion of the resource at the expense of others
As populations density increases, “commons tragedies” increase.
Take home message: Any resource openly shared will eventually be destroyed because everyone will use it and no one will be responsible for preserving it

4. Human Activities- Tragedy of the Commons
Overexploitation of cod fishery- grand banks. Fishery was found in international waters, so boats from many different countries were harvesting fish. Each group was racing to catch the fish before another ship. No one was concerned about the stability of the fish population, only their own profits.

5. Quick Activity
Classify the following resources as renewable or nonrenewable:
Solar energy
Wind/air
Water
Fossil fuels
Metals
Soil
Plants
Animals

6. Types of Resources
Environmental resources can be classified into two categories:
Renewable =can regenerate and are replaceable (trees, water), but not necessarily unlimited
The classification “renewable” depends upon the context in which you use it. (For example, a forest is not renewable, because the climate would change if all trees were cut down, but individual trees are renewable)
Think replenished in the short term 1-10 years…
Nonrenewable = cannot be replenished by natural processes (fossil fuels, coal, oil, natural gas)
Sustainable use = way of using natural resources at a rate that doesn’t deplete them to make sure renewable resources are available for future generations

7. Renewable resources Land resources Forest resources Ocean resources
Human activities affect the supply and the quality of renewable resources including:
Land resources
Forest resources
Ocean resources
Air resources
Water resources

8. Changing landscape
Past and present humans have had a powerful influence on the physical and living world by modifying their environment.
Our practices are changing the environment!
From deforestation to fishing
We used the environment for food, medicine, wood, and fiber
We introduced new species, predators, agriculture, industry, and disease
The world is very different from what it was long ago.
Think of Earth as an island – all of the organisms that live on Earth share limited resources and increasing population sizes place greater demands on the biosphere

10. Land resources
Provide space for cities and suburbs, raw materials for industry, and fertile soil with nutrients and moisture to grow plants with roots to hold soil against rain and wind
Negative activities:
Soil erosion = wearing away of surface soil by water and wind (usually results from removing roots that hold soil through plowing, mowing, road building, etc.)
Typical midwest high plains field loses 47 tons of soil/year
Soil is the top pollutants in most aquatic systems
Desertification = turning once productive areas into deserts (usually results from farming, overgrazing, and drought)
Positive activities:
Sustainable agriculture = practices that reduce soil erosion by conserving soil’s properties

12. Sustainable Agriculture
Cover Crops
Legumes, grasses, and other
cover crops recycle soil nutrients,
reduce fertilizer need, and
prevent weed growth.
Controlled Grazing
By managing graze periods and herd
densities, farmers can improve nutrient
cycling, increase the effectiveness of
precipitation, and increase the carrying
capacity of pastures.
Biological Pest Control
The use of predators and parasites
to control destructive insects
minimizes pesticide use as well as
crop damage
Contour Plowing
Contour plowing reduces
soil erosion from land runoff.
On hilly areas, plowing is done
across the hill rather than
straight up and down.
Crop Rotation
Different crops use and
replenish different nutrients.
By rotating crops, the loss
of important plant nutrients
is decreased. A B C
Yr. 1
Yr. 2
Yr. 3
Section 6-4
Sustainable Agriculture
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corn
alfalfa
oats
alfalfa (plowed in)

13. Good Bad

14. Forest resources Negative activities:
Provide wood for homes, paper, fuel and “lungs of the Earth” because they remove carbon dioxide and produce oxygen, store nutrients, provide habitats and food, moderate climates, limit soil erosion, and protect fresh water supplies
Negative activities:
Deforestation = loss of forests leading to:
soil erosion, loss of biodiversity, ecosystem services
Increase in likelihood of global climate change

15. Clear Cutting

18. Forest Resources Positive activities:
Forest Management= actively monitoring and influencing the forest to improve quality and production of timber
Sustainable forestry= plant, promote growth, manage, harvest and replant trees to preserve the ecosystem
Harvest trees at low levels, replanting seedlings to replace harvested trees.
Selective Cutting- remove only mature, high value trees, leave forest intact

19. Sustainable Practices

20. Ocean resources
Provides protein-rich food (cod and shrimp), plankton produces oxygen and fixes CO2, Controls climate of planet
Negative activities:
Overfishing = fish are being harvested faster than they can reproduce
Bycatch= organisms (invertebrates, dolphins, sharks, turtles, etc.) caught unintentionally while a fishery targets other species
May be sold
May be disposed of

21. World wide, only 10 percent of original predatory fish populations remain in the worlds oceans
Industrial fisheries reduce biomass by an average 80 percent in years
Based on one study by Meyers and Worm, with data from Japanese long-lining data and inshore trawl surveys. The numbers of large fish are down 90 percent form pre-exploitation numbers, and the fish that are around are 1/5 to ½ the size they used to be. On average it only takes years for an industrialized fishery to reduce the areas biomass by 80%. This is in part due to large amounts of by catch, and other harmful fishing methods.

22. Fishing Down Food Webs
Practice in which fisheries simply concentrate on smaller species, once the larger ones have been overexploited
Now a common practice
Since mean trophic level of landings world wide has fallen
It’s a common practice that once a larger species has been overexploited, fishermen move down the food chain, to a smaller species, one that could possibly have had short-term benefits from declines in the numbers of their predators, but in the end experience a long-term population decline due to the new fishery. Makes it extremely hard for exploited species to recover, when fisheries switch over to their food sources. This process continues all the way down the food chain, effectively removing all organisms. Some people believe that eventually all people may have left will be phytoplankton.

23. Down the web… Past 45 years:
Shift from large piscivorous fish, to small invertebrates and planktivorous fishes, especially in the northern oceans.
These shifts tend to interrupt entire food chain, and can result in abundance of unusable species
Norway Pout  Krill  copepods
 More valuable commercial species
Fishing down food webs, results in a change of targeted species from dominant predators, to smaller previously thought of “feeder” fish. This is especially apparent in northern seas where fisheries have been more developed. Most times these changes affect other organisms through changes in the food webs themselves. Less Norway pout= more krill = less copepods = les of the more valuable commercial species.

24. Consequences of Fishing Down
consist of:
a gradual loss of large organisms
loss of species diversity
loss of structural diversity
gradual replacement of recently evolved, derived groups (marine mammals, bony fishes) by more primitive groups (invertebrates, notably jellyfishes, and bacteria)
Fishing down results early on in economic benefit along with lower CPE’s, but gradually harms the ecosystem drastically, possibly preventing recoveries. Fishing down eliminates food, and resources for top predators, which were probably over-fished to begin with, instead faster-growing, valueless groups move in, such as jellyfish (black sea).

25. Japanese Long Lining
Data from Japanese long line fisheries illustrates the decline of top trophic level fish around the world.
Japanese long line fleet is the most extensive in the entire world, covering all oceans except the circumpolar seas
Long lines used to catch 10 fish per 100 hooks, now lucky to catch 1
Long lines target higher trophic level fish, such as billfish in the open oceans. Average catch per hook has dropped dramatically. New areas productive for short time, then fall off.

26. Three Habitat Types Pristine Exploited Fully degraded
Top predators present with large biomass
Benthic fauna- abundant structure forming and sessile organisms
Exploited
Declines (size of catch, number of individuals, trophic level of catch ; also decline in benthos)
Fully degraded
Most species absent, including key-stone species
Combined with pollution may result in a “dead zone”
Very few pristine environments left, except possibly some of the southern pacific. Exploited environments often have a reduction in benthic fauna due to damages caused by trawling. Declines in body size of catch result from removing prime specimens first. Eventually down-web fishing occurs. Fully degraded environments are characterized by a lack of benthos, no commercially valuable species, and a “barren desert” under the water.

27. Conclusions (same as always)
Protected (no fishing) areas need to be created
In the next decades, fisheries need to concentrate on rebuilding stocks, with respect to the food webs that used to exist.
Difficult in the beginning, but benefits in the long term: if stocks increase only 1/3 to 1/10 of the effort may be required to reach current catch levels
One way to accomplish this is to reduce by catch by a large amount (suggested that up to 50% of fishing mortality needs to be avoided for stocks to recover)
Not too late to avoid turning many of the oceans into fully degraded bodies of water. This requires efforts not only from law makers, but from the actual fishermen also. It also requires short-term sacrifice for long-term gain. Instead of using helicopters and satellites to target the last of all the great fish, and large school, we should back of fishing pressure, encouraging populations to recover.

28. Amount of Fish per Person
Growth of Fish Catch
Larger fishing boats with better technology for locating and catching fish
Section 6-2
World Fish Catch
World Fish Catch per Person
Total Catch
(million tons)
Amount of Fish per Person
(kilograms)
Year
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29. Ocean- Positives Positive activities:
Limit the catch of fish populations
Aquaculture = farming of aquatic organisms
Reducing bycatch- improved methods and technologies
Creation of marine preserves

30. Marine preserves, reducing bycatch, and fish farming?

31. Air resources Used to breathe Negative activities:
Pollutant = harmful material that can enter the biosphere through the land/air/water
Smog = mixture of chemicals that results in a gray-brown haze in the atmosphere mostly due to car exhausts and industrial emissions causing respiratory conditions
Acid rain = mixture of acidic gases (nitrates and sulfates) from combustion with water vapor- damaging plants, soil and water
Positive activities:
Clean-air regulations and controlling emissions has improved air quality

33. Emissions to Atmosphere Chemical Transformation
The Formation of Acid Rain
Section 6-2
Emissions to Atmosphere
Nitrogen oxides
Sulfur dioxide
Chemical Transformation
Nitric acid
Sulfuric acid
Precipitation
Acid rain, fog,
snow, and mist
Dry Fallout
Condensation
particulates, gases
Industry
Transportation
Ore smelting
Power generation
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34. Water resources
Billions of gallons of water are used daily by Americans for drinking, washing, watering crops and making steel (“everyday use”)
Negative activities:
Our renewable water supply can be limited by drought, overuse, oil spills, improperly discarded chemicals and waste (sewage)
High levels of nitrogen and phosphorous due to excess fertilizer runoff- causes:
Eutrophication- excess algae growth and oxygen depletion
Positive activities:
Protect natural cycles because plants naturally filter and purify water = Fresh Water Wetlands Act
Water conservation
Clean Water Act
Low flow fixtures are limiting waste water

37. Excess Phosphorus and Nitrogen