Transcript Water!! - Lemon Bay High School

APES: Chapter 12
Water!!
Water!!
In Groups of 4:
• What is the difference between:
– Aquatic
– Marine
– Limnology
– Freshwater
• How much of our world is covered in water?
– Fresh vs salt
• List @ least 5 ways humans use water
Freshwater First ;)
D:\Chapter_12\C_Animation_and_Video_Files\
ABC News Video Clips\water_wars
Activity:
• Same Groups, Using your textbook:
– List the freshwater systems
– What is the difference between consumptive and
non-consumptive use? Give examples
– List the 4 ways humans use water
– Check out figure 12.10 page 263: what are your
thoughts?
– Answer the Weighing the Issues Reaching for
Water on page 264 as H/W tonight
APES: Chapter 12
Water!!
Water!!
Most Water is in the Ocean
• ~97.5% of water on Earth is in the ocean
– ~2.5% is considered Fresh
So lets talk Freshwater
• Name some freshwater ecosystems
– Rivers, bogs, marshes, lakes, ponds, streams, swamp
• How does groundwater effect hydrologic
system?
– Storage of freshwater to be used slowly, and
replenished in equal amounts
• What is an aquifer?
– Areas of in-ground water storage: rock that is spongy
or porous (rock, sand or gravel)
Stats:
• Ground waters average age: 1,400 years!!
– Some can be 10’s of thousands of years old!!!!
• The US releases 492 Billion gallons of water
per day from its aquifers!!!!
• On average, surface water enters aquifers at a
rate of 3 ft per day.
• Is this sustainable?
We are depleting groundwater
• Groundwater is easily depleted, because aquifers
recharge slowly.
– Most water goes to agriculture.
– Amount of irrigated land is increasing.
– Water is being “mined”: 15-35% of irrigation
withdrawals are unsustainable.
• As aquifers become depleted:
– Water tables drop
– Salt water intrudes in coastal areas
– Some cities (Venice, Mexico City) are slowly sinking
– Wetlands dry up
The Ogallala Aquifer
• The world’s largest
known aquifer
• Underlies Great Plains
of U.S.- 8 states
• Most bountiful grainproducing region in
world because of H2O
• It is down 10% = 18
yrs of Colorado River
Flow!!
Overpumping has reduced the aquifer’s volume by 10%.
Equal Shares for Everyone?
• No….
• Water is NOT infinite and everywhere
• MANY MANY nations with high populations of
people have very very little water
– Or no access to it
Water is unequally distributed in space and time
• Different regions possess different amounts of groundwater,
surface water, and precipitation.
• Many areas with high population density are water-poor and face
serious water shortages.
• Dams store water so it can be used when needed.
Climate change may bring water
shortages
• Climate change will cause:
– Altered precipitation patterns
– Melting glaciers
– Early season runoff
– Intensified droughts
– Flooding
• Models predict a drier future for the
American Southwest.
– 4 western states are building new
water supply projects for $2.5 billion.
Activity:
• Comprehension question 1-3 due today
• Print off Section 1 readings to work on in class
Monday….. Quite a lot of work, so if you
complete over the weekend… ;)
Homework for This Weekend:
• Pre-read next section:
– “Solutions to Depletion of Fresh Water”
• Answer Questions 4-5 of Testing Your
Comprehension
• Print off and complete from web-site,
– “Ch 12 Freshwater Activity,”.
• Be prepared to discuss on Monday, must have work
available for a grade ;)
Activity:
• In groups of 2:
– Explain how a dam works (p. 361-363) and what they do:
remember that dams of today are very different
• Include the terms Consumptive/Nonconsumptive
• Where are the largest dams located
• Include both benefit and cost
– What is a Dike/Levee? How do they work, etc.
• Benefit vs cost
– How/Why are we depleting Surface Water?
• Benefit vs cost
• Give examples
– How/Why are we depleting Ground Water?
• Benefit vs cost
• Give Examples
– What is the future outlook when it comes to Water Wars?
We have erected thousands of dams
• Dam: an obstruction placed in a river or stream that blocks
water flow so that water can be stored in a reservoir
– Prevents floods, provides drinking water and irrigation,
and generates electricity
• Only a few major rivers in remote regions remain undammed.
• Dams are dismantled when their costs outweigh their
benefits.
– 500 dams have been removed in the U.S.
• Rivers with dismantled dams:
– Have restored riparian ecosystems
– Reestablished fisheries
– Revived river recreation
A typical dam How it works
Problems???
•
•
•
•
•
•
What happens when you build a dam?
HELP!!
Sediment accrues up river
Sediment is washed out downstream
Ecosystems are destroyed
Areas are flooded, encasing all materials in
water
– Factories, chemicals, grasslands, habitat, homes….
China’s Three Gorges Dam
• The largest in the world
– Electricity, shipping, flood
control
– May replace coal or nuclear
plants
•
•
•
•
•
•
Cost $25 billion to build
10 trillion gallons of water
Flooding cities/homes 1.2 mil displaced
Submerging archaeological sites
Drowning farmland /wildlife habitat
Suspended sediments/waste/will fill the
reservoir
• Sub-climates/hydrologic cycle changes
On the Other Hand…..
• At full power, Three Gorges reduces coal
consumption by 31 million tonnes per year,
avoiding 100 million tonnes of greenhouse
gas emissions, millions of tonnes of dust, one
million tonnes of sulfur dioxide, 370,000
tonnes of nitric oxide, 10,000 tonnes of
carbon monoxide, and a significant amount of
mercury. Hydropower saves the energy
needed to mine, wash, and transport the coal
from northern China.
Cntd
• From 2003 to 2007, power production equaled that of
84 million tonnes of standard coal, reducing carbon
dioxide by 190 million tonnes, sulfur dioxide by 2.29
million tonnes, and nitrogen oxides by 980,000 tonnes.
• The dam increased the Yangtze's barge capacity sixfold,
reducing carbon dioxide emission by 630,000 tonnes.
From 2004 to 2007 a total of 198 million tonnes of
goods passed through the ship locks. Compared to
using trucking, barges reduced carbon dioxide emission
by ten million tonnes and lowered costs by 25%.[65]
Wikipedia
Will we see a future of water wars?
• Freshwater depletion leads to shortages, which can
lead to conflict.
– 261 major rivers cross national borders.
– Transboundary disagreements are common.
– Water is a key element in hostilities among Israel,
Palestinians, and neighboring countries.
• Many nations cooperate with neighbors to resolve
disputes.
– Treaties have been signed by nations in Europe along the
Rhine and Danube rivers.
– What do YOU think?????
– Another way to die!!!
Activity:
• Pre-read next section, “Solutions to Depletion
of Fresh Water”
• Answer Questions 4-5 of Testing Your
Comprehension
• Print off and complete from web-site, Ch 12
Freshwater Vocabulary
• Be prepared to discuss tomorrow, must have
work available for a grade ;)
Waste-water Treatment
APES
Water: The Story of Stuff
Indicators of water quality
• Scientists measure properties of water to
characterize its quality.
– Biological indicators: presence of fecal coliform
bacteria, algae, and aquatic invertebrates
– Chemical indicators: nutrient concentration, pH,
taste, odor, hardness, dissolved oxygen
– Physical indicators: temperature, color, turbidity
Groundwater pollution is a serious
problem
• Groundwater pollution is hidden (“out of sight, out of mind”).
– Difficult to monitor and manage
– Retains contaminants for decades and longer
• Some toxic chemicals occur naturally.
– Aluminum, fluoride, sulfates, arsenic
• Pollution from human activity is widespread.
– Wastes leach through soils
– Pathogens enter through improperly designed wells.
– Hazardous wastes are pumped into the ground.
– Underground storage and septic tanks may leak.
Legislative efforts reduce pollution
• Clean Water Act (1977)
– Illegal to discharge pollution without a permit
– Standards for industrial wastewater
– Funded construction of sewage treatment plants
• Legislation has improved the situation.
– Conditions improve when citizens push governments.
• Other nations have also reduced pollution.
We treat our drinking water
• EPA sets standards
– It is chemically treated, filtered, and disinfected
• Wastewater: water that has been used by people
– Sewage, showers, sinks, manufacturing, storm water runoff
• Septic systems: wastewater disposal in rural areas
– Underground septic tanks separate solids and oils from
wastewater.
– The water drains into a drain field and decomposes.
– Solid waste is periodically pumped and landfilled.
Municipal sewer systems
• In populated areas, sewer systems carry wastewater.
– Physical, chemical, and biological water treatment
• Primary treatment: the physical removal of contaminants in
settling tanks (clarifiers)
• Secondary treatment: water is stirred and aerated so aerobic
bacteria degrade organic pollutants
– Chlorine-treated water is piped into rivers or the ocean.
– Reclaimed water can be used for irrigation, lawns, or
industry.
– Dried solid material (sludge) is landfilled, incinerated, or used
as fertilizer.
A typical wastewater treatment facility
Artificial wetlands
• Natural and artificial wetlands can cleanse
wastewater.
– After primary treatment at a conventional facility,
wastewater is pumped into the wetland.
– Microbes decompose the remaining pollutants.
– Cleansed water is released into waterways or percolated
underground.
• Constructed wetlands serve as havens for wildlife
and areas for human recreation.
– More than 500 artificially constructed or restored
wetlands exist in the U.S.
Activity:
• Pre-read next section; Marine and Coastal
Ecosystems: pages 269-275
• Answer Questions 6-7 of Testing
Comprehension
Activity:
• List the 5 major oceans; describe the physical makeup of the ocean
– Include; currents, Coriolis Effect (p. 286), Upwelling, Downwelling,
Marianas Trench, the longest mtn chain, convergent/divergent/transform
fault boundaries (p. 236 237), photic/benthic/pelagic zones
• The text list 8different coastal ecosystems. List them including unique features
• Figure 12.17 shows the profile of the benthic zone;
– Where does seafloor spreading occur? Sub-duction? What can you expect
along trenches? Is the Pacific or the Atlantic more likely to have seismic
activity? why?
• Compare/Contrast the following: rocky intertidal zone, salt marsh, mangrove
forest.
– Include where they are located
• ~2/3rds of human pop. Live w/in 100 miles of an ocean. Describe the ways in
which this has altered these ecosystems.
Due to me: Monday, 3/17/14
Lets Mix it Up!!
• Shannon, Caitlyn, Jessica:
– Marine and Coastal Systems (Near surface pelagic
ecosystems, Deep Ocean, Kelp Forest, Coral Reefs)
• Sinead, Olivia, Conner:
– Human Use and Impact (Intertidal Zones, Salt
Marshes, Mangrove Forest, Estuaries)
• Dani, Marissa, Donald:
– Overfishing and Marine Conservation
Marine and coastal systems
• Oceans cover 71% of Earth’s surface and contain 97% of
Earth’s surface water.
– Influence global climate, high biodiversity, facilitate
transportation and commerce, and provide resources
• Ocean water is 96.5% water, plus ions of dissolved salts.
– Evaporation removes pure water, leaving salt behind.
• Surface water is warmer than subsurface water.
– Warmed by sun, and is less dense
• Deeper water is dense, sluggish .
– Unaffected by winds, storms, sunlight, and temperature
Ocean water flows horizontally in
currents
• Currents: vast riverlike flows in the upper 400 m
– Driven by wind, density differences, gravity, heating, and
cooling
– Influence global climate and El Niño and La Niña
A stylized profile of the ocean
• Upwelling: the vertical flow of cold, deep water toward the
surface
- High primary productivity and lucrative fisheries
• Downwelling: oxygen-rich water sinks, providing oxygen for
deep-water life
Seafloor topography is complex, with
volcanoes, canyons, and mountains.
Regions of ocean differ greatly
• Some zones support more life than others.
• Photic zone: well-lighted top layer that supports
high primary productivity
– Warm, shallow waters of continentel shelves
• Pelagic: habitats and ecosystems occurring
between the ocean’s surface and floor
• Benthic: habitats and ecosystems occurring on
the ocean floor
Near-surface pelagic ecosystems
• Photosynthetic productivity
occurs in surface waters near
upwellings.
• Microscopic phytoplankton
constitute the base of the
marine food chain.
• These organisms feed
zooplankton.
– Which then feeds fish, jellyfish,
whales, etc.
• Predators at higher trophic levels
include larger fish, sea turtles,
sharks, and fish-eating birds.
Animals of the deep ocean
• Animals adapt to extreme water
pressure and the absence of light.
– Scavenge carcasses or organic
detritus
– Some are predators, while others
have mutualistic relationships
with bacteria.
• Hydrothermal vents: heated water carrying minerals spurts
from the seafloor
- Support tubeworms, shrimp, and other species
Kelp forests
• Kelp: large brown algae growing from the floor of continental
shelves
• Dense strands form kelp forests up to 60 m (200 ft) tall along
temperate coasts.
• Shelter and food for organisms
• Absorbs wave energy and protects shorelines from erosion
• Alginates serve as thickeners in cosmetics, paints, paper, and
soaps
Coral reefs
• Corals: tiny marine organisms that live in
shallow subtropical and tropical waters
– Attach to rock or existing reef and
capture passing food with stinging
tentacles
– Derive nourishment from symbiotic
algae, zooxanthallae
• Coral reef: a mass of calcium carbonate
composed of the skeletons of millions of
densely packed corals
– Protects shorelines by absorbing waves
– Staggering biodiversity
Intertidal zones
Anemones, mussels,
urchins, limpets, seastars,
and crabs abound.
• Intertidal (littoral) zones: where the ocean meets the land
– Between the farthest reaches of the high and low tides
• Tides: periodic rising and falling of the ocean’s height due to the
gravitational pull of the sun and moon
– Intertidal organisms spend part of their time submerged in
water and part of their time exposed to sun and wind.
Salt marshes
• Salt marsh: occur along coasts at temperate
latitude
– Tides wash over gently sloping, sandy, silty substrates.
– High primary productivity
– Critical habitat for birds and commercial fish and
shellfish species
Mangrove forests and estuaries
• Mangroves: sandy coasts in tropical and subtropical latitudes
– Tree roots curve up for oxygen, and down for support.
– Nurseries for fish and shellfish
– Nesting areas for birds
– Protect coastlines
• Estuaries: where rivers flow into the ocean
– Mixing fresh water with salt water
• Critical habitat for shorebirds and shellfish
• Fish spawn in freshwater, mature in salt water
Humans affect these ecosystems
• All coastal and nearshore ecosystems are impacted by humans.
– 67% of humans live within 160 km (100 mi) of the ocean.
• Estuaries, salt marshes, mangroves, and coral reefs
– Urban and coastal development
– Water pollution
– Habitat alteration, overfishing
• Coral bleaching: zooxanthellae leave corals, depriving them of
nutrition
– Warmer water from climate change, pollution, eutrophication,
acidified seawater
Activity:
• Pre-read next sections: Human Use and
Impact, and Overfishing and Marine
Conservation, p. 275-281
• Answer the following Testing Your
Comprehension Questions: 8-10
• Answer Question 4-5 of Seeking Solutions
Activity:
Humans are threatening the oceans
• Oceans provide transportation routes, energy, and minerals.
– Moving people and products over vast distances
– 25% of our crude oil and natural gas
– Methane hydrate: a potential energy source
– Sand, gravel, copper, manganese nodules
• Up to the mid-20th century, coastal U.S. cities dumped trash
and untreated sewage along their shores.
– Oil, plastic, chemicals, excess nutrients make their way
from land into oceans.
– Raw sewage and trash from cruise ships
– Abandoned fishing gear from fishing boats
Marine pollution: nets and plastic
debris
• Plastic items dumped into
the sea harm or kill wildlife.
• Plastic is non-biodegradable.
– Drifts for decades
– Washes up on beaches
– Wildlife eat it or get entangled
and die
• Minimize this harm by
reducing plastic use and
cleaning beaches
Marine pollution: oil pollution
• Although major oil spills make headlines and cause serious
problems, most pollution comes from small sources.
- Boat leakage, runoff, naturally occurring seabed leaks
• Oil spills:
- Coat and poison wildlife
- Devastate fisheries and local economies
• Oil spills have decreased due to stricter
regulations.
• The U.S. Oil Pollution Act of 1990
– Prevention and clean-up fund
– All ships must have double hulls by 2015
Excess nutrients cause algal blooms
• Creates dead zones in coastal ecosystems
• Harmful algal blooms: population explosions of algae that
produce powerful toxins
• Red tide: algal species produce reddish pigments that
discolor water
– Illness and death to wildlife and humans
– Economic losses to fishing industries and beach tourism
We are emptying the oceans
• Overharvesting is the most serious threat to the
oceans.
• We are placing unprecedented pressure on marine
resources.
– Half the world’s marine fish populations are fully
exploited.
– 25% of fish population are overexploited and heading to
extinction.
• Total fisheries catch leveled off after 1998, despite
increased fishing effort.
The total global fisheries catch is
stalling
Fishing has industrialized
• Today’s commercial fishing fleets are highly industrialized, huge
vessels that use powerful technologies to capture fish in huge
volumes.
– Even process and freeze their catches while at sea
• Driftnets: span large expanses of water to capture passing fish
• Longline: extremely long lines with thousands of hooks
• Trawling: entrails dragging immense nets through the water or
on the ocean floor
Fishing practices damage the oceans
• By-catch: the accidental capture of
animals
• Driftnetting drowns dolphins, seals, sea
turtles, non-target fish
• Longline fishing kills turtles, sharks, and
seabirds
• Bottom-trawling destroys communities
Industrialized fishing depletes
populations
• Oceans contain only 10% of the large-bodied animals they once
held.
• Many fisheries have collapsed.
– Ecologically devastating, with severe economic tolls
– Closing fisheries helps some populations rebound.
• The decline of fisheries has been hidden.
– Fishing fleets travel longer distances, to deeper water.
– Fleets spend more time fishing and increasing effort to catch
the same number of fish.
– Improved technologies: faster ships, sonar mapping, satellite
navigation, thermal sensing
We are “fishing down the food chain”
• As fishing increases, the size and age of fish caught decline.
– As species become rare, fleets target other species.
– Fleets catch smaller, less desirable species.
– Catch species at lower trophic levels
• Consumer choices influence fishing practices.
– Buy ecolabeled seafood (i.e., “Dolphin-safe tuna”)
– Non-profit organizations have devised guides to help consumers.
Fisheries management
• Management was based on maximum sustained
yield.
– Maximal harvest while keeping fish available for the future
• Despite management, stocks have plummeted.
– It is time to rethink fisheries management.
• Ecosystem-based management:
– Shift away from species and toward the larger ecosystem
– Consider the impacts of fishing on habitat and species
interactions
– Set aside areas of oceans free from human interference
We can protect areas in the ocean
• Marine protected areas (MPAs): established along the coastlines
of developed countries
– Still allow fishing or other extractive activities
• Marine reserves: areas where fishing is prohibited
– Leave ecosystems intact, without human interference
– Improve fisheries, because young fish will disperse into
surrounding areas
– Benefits: increased species density, biomass, size, diversity
• Many commercial and recreation fishers and businesses do not
support reserves.
Conclusion
• Maintaining saltwater and freshwater resources will
be an environmental challenge.
• Use of freshwater for drinking, irrigation, and other
purposes depletes many water sources.
• Overfishing imperils ocean fish stocks.
• Coastal development harms natural systems.
• Pollution degrades water quality.
• There is reason for optimism: water quality is
improving and marine reserves give hope for
ecosystem restoration and the future of fisheries.
QUESTION: Review
The area of a lake that extends along the entire
bottom of the water body is called the:
a)
b)
c)
d)
e)
Littoral zone
Benthic zone
Limnetic zone
Profundal zone
Lacustrine zone
QUESTION: Review
Shallow water that occurs in a forested area is a(n):
a)
b)
c)
d)
e)
Wet lake
Marsh
Swamp
Bog
Eutrophic lake
QUESTION: Review
The major use of water, globally, is:
a)
b)
c)
d)
e)
For developing industries
In agriculture
In households
Exported to rich countries
In industries
QUESTION: Review
Which of the following is NOT a way to reduce
agricultural water demand?
a)
b)
c)
d)
e)
Lining irrigation canals
Match crops to land and climate
Use low-pressure irrigation systems
Install low-flow faucets in work stations
Selective breeding of crops
QUESTION: Review
Pollution is defined as “the release of matter or
energy into the environment that causes ______.”
a)
b)
c)
d)
e)
Undesirable impacts on human health
Undesirable impacts on other organisms
Undesirable impacts on human well-being
A, b and c are included in the definition.
None of these is included in the definition.
QUESTION: Review
Which of the following is a toxic chemical water
pollutant?
a)
b)
c)
d)
e)
Pesticides
Petroleum products
Mercury
Acid rain
All of these are toxic chemicals.
QUESTION: Review
Primary treatment of wastewater includes:
a)
b)
c)
d)
e)
Treating water with chemicals
Stirring and aerating water
Degradation of wastes by bacteria
Physical removal of contaminants
Diverting the water into a stream
QUESTION: Review
A “downwelling” is defined as:
a) The vertical flow of cold, deep water toward the
surface
b) The vertical flow of cold, shallow water toward the
bottom
c) The vertical flow of warm, deep water toward the
bottom
d) The flow of oxygen-rich water into deep water
e) The flow of oxygen-rich water into shallow areas
QUESTION: Review
Which of the following is defined as “large brown
algae growing from the floor of continental shelves”?
a)
b)
c)
d)
e)
Kelp forests
Coral reefs
Intertidal zones
Salt marshes
Mangrove swamps
QUESTION: Review
Coral bleaching occurs when:
a)
b)
c)
d)
e)
Corals reproduce
Fish move into coral reefs
Zooxanthellae leave the coral
Coral reefs expand their range
Fishermen make jewelry from coral
QUESTION: Review
Marine reserves have all the following benefits
EXCEPT:
a)
b)
c)
d)
e)
Diversity increases in the reserve
The size of fish increases
Larvae can “seed” areas outside the reserve
Fish biomass increases
All of these are benefits of marine reserves.
QUESTION: Interpreting Graphs and
Data
What does this graph show about the future of
global fisheries catch?
a) Total global fisheries catch
has declined significantly.
b) Total global catch has
leveled off.
c) China’s catch has
increased since 2000.
d) The U.S. is mad at the
declining catch.
e) We will find more fish to
catch.
QUESTION: Viewpoints
In 2001, the federal government issued orders to
divert irrigation water downstream to save
endangered fish. Angry farmers ignored this
order, and instead used this water for their fields.
What should happen to the farmers?
a) Nothing. They need the water for their crops.
b) They should be fined for breaking the law.
c) They should be paid subsidies so they can
continue farming.
d) They should be paid to plant different crops that
do not require so much water.
QUESTION: Viewpoints
Should cities in desert areas such as Las Vegas be
allowed to increase their populations, even though
this will require more water?
a) Yes, it’s not the American way to limit what cities
can do.
b) Yes, but the people will have to pay the true cost of
water.
c) Yes, but only if the people are required to use
drastic conservation measures.
d) No, enough is enough, and cities in arid
environments simply cannot continue growing.
QUESTION: Viewpoints
Do you plan to alter your decisions about eating
seafood?
a) Yes, I will be more selective about what I eat.
b) No, I will continue to eat the same type and
amount of seafood as always.