Freshwater Streams and Rivers Carry
Water from the Mountains to the Oceans
Surface water (precipitation that does
not sink into the ground or evaporate)
Runoff (when H2O flows into streams)
Watershed (drainage basin)
The Chattahoochee River begins as a spring in the
fittingly name "Chattahoochee Gap," little more than a
trickle of water at 3200 feet. Over the first 100 miles the
river falls almost 2400 feet, forms a major Southeast
lake (Lanier) and provides water for millions of
Georgians.
With its headwaters in the Blue Ridge Mountains, 200
feet from the Appalachian Trail, the Chattahoochee
flows 430 miles through Georgia. The lower portion of
the river is the boundary between Georgia and
Alabama and between Georgia and a small portion of
Florida. It joins the Flint River at Lake Seminole and
forms the Apalachicola River, which flows 106 miles
through Florida to the Gulf of Mexico.
The origin of the Chattahootchee
River is near Brasstown Bald,
Georgia’s highest point.
3 AQUATIC LIFE ZONES
Source zone- cold, shallow, swift flowing, lack of
nutrients, lots of DO, cold water fish (trout),
rocky,
Transition zone - headwater streams merge and
form warmer, streams with gentle slopes and less
DO. Can support more producers. Water often
turbid due to suspended sediments
Floodplain zone – wide, deep rivers that flow
across broad, flat valleys. Higher temperatures
and less DO
Freshwater Inland Wetlands Are
Vital Sponges
Marshes
Swamps
Prairie potholes (depressions created by
glaciers)
Floodplains
Arctic tundra in summer
Provide free ecological and economic services
Filter and degrade toxic wastes
Reduce flooding and erosion
Help to replenish streams and recharge groundwater
aquifers
Biodiversity
Food
Recreation areas
Areas Susceptible
To Flo0ding
New Orleans – contains 40% of all
U.S. wetlands and has lost over 1/5 to
oil/gas well/coastal development
U.S. Gulf Coast
Venice, Italy
Dams and levees are built to help
control flooding and provide
electricity.
Disadvantages of dams
and levees
Traps sediments from entering
deltas
Deltas are sinking, wetlands are
flooded
Less wetlands=saltwater intrusion
WHY ARE WETLANDS
IMPORTANT?
Provide habitats for plants, insects and birds
Are one of most productive ecosystems
Are spawning zones for fish, nesting areas for birds
Trap carbon (vegetation)
Filter pollutants and fertilizers before they reach the
water table
Control flooding
Produce food such as cranberries, blueberries
Produce peat moss
Are enjoyed by humans - fishing, hiking, canoeing,
etc,…
Hurricane KatrinaAugust 29, 2005
Storm surge
80% of city underwater at some
point
1800+ people died and over
$100 billion of damage
New Orleans is 10 feet below sea
level
Freshwater Inland Wetlands
MARSHES
Have nonwoody
plants
The Florida
Everglades
SWAMPS
Contain woody
plants
Okefenokee
Swamp
Cypress trees
marsh,
bog,
pothole,
cranberries
Human Activities Are Disrupting and
Degrading Freshwater Systems
Impact of dams and canals on rivers
Impact of flood control levees and
dikes along rivers
Impact of pollutants from cities and
farms on rivers
Impact of drained wetlands
Sustaining
Aquatic
Biodiversity
Chapter
11
What Are the Major Threats to
Aquatic Biodiversity?
Greatest marine biodiversity…
Coral reefs
Estuaries
Deep-ocean floor
(great variety of habitats and food)
Biodiversity is higher…
Near the coast than in the open sea
In the bottom region of the ocean than
the surface region
Human Activities Are Destroying and
Degrading Aquatic Habitats
Habitat loss and degradation
Marine
Coastal
Ocean floor: effect of trawlers and
dredging
Freshwater
Dams
Excessive water withdrawal – mostly
for agriculture
Invasive Species Are Degrading
Aquatic Biodiversity
Invasive species
Threaten native species
Disrupt and degrade whole ecosystems
84% of coastal waters are affected
Three examples
Water hyacinth: Lake Victoria (East Africa)
Asian swamp eel: waterways of south Florida
Purple loosestrife: indigenous to Europe
Treating with natural predators—a weevil
species and a leaf-eating beetle—Will it
work?
Water hyacinththe worse invasive
water plant!
Purple loosestrifeinvasive plant that
takes over wetlands
Swamp eels- people
eat, but they
compete with native
species!
Population Growth and Pollution Can
Reduce Aquatic Biodiversity
Nitrates and phosphates mainly
from fertilizers enter water
Leads to eutrophication
Toxic pollutants from industrial
and urban areas (and plastics!)
Climate Change Is a Growing
Threat
Global warming: sea levels will
rise and aquatic biodiversity is
threatened
Coral reefs
Swamp some low-lying islands
Drown many highly productive
coastal wetlands
New Orleans, Louisiana, and New
York City
Why is it hard to protect marine
biodiversity?
Human ecological footprint and
fishprint are expanding
Much of the damage in the ocean is
not visible
The oceans are incorrectly viewed
as an inexhaustible resource
Most of the ocean lies outside the
legal jurisdiction of any country
Blue whale
The world’s largest animal
Endangered since 19
Adult heart is the size of a
Volkswagen Beetle
250,000, now 5,000
Hunted for oil, meat and bone
Protecting Whales:
A Success Story… So Far
Cetaceans: Toothed whales
and baleen whales
1946: International Whaling
Commission (IWC)- set quotas
1970: U.S.
Stopped all commercial whaling
Banned all imports of whale
products
1986: moratorium on
commercial whaling
Pros
Cons
Holding Out Hope for
Marine Turtles
Carl Safina, Voyage of the
Turtle
Studies of the leatherback
turtle
Threats to the
leatherbacks
Trawlers
Pollution
Climate change
Communities protecting
the turtles
Last Journey for the
Leatherback
http://video.google.com/videopl
ay?docid=5659656568361844117#
13:35 minutes
Marine Sanctuaries Protect
Ecosystems and Species
Offshore fishing
370 km (200 statute miles)
Exclusive economic zones – other
countries can fish w/ quotas
High seas
Law of the Sea Treaty (world’s coastal
nations have jurisdiction over 36% of
ocean surface and 90% of fish stock
Marine Protected Areas (MPAs) –
areas protected from human activities
Establishing a Global Network
of Marine Reserves
Marine reserves
Closed to
Commercial fishing
Dredging
Mining and waste disposal
Goal is to allow areas to recover
Core zone
No human activity allowed
Less harmful activities allowed
E.g., recreational boating and
shipping
Fully protected marine reserves
work fast
Fish populations double
Fish size grows
Reproduction triples
Species diversity increase by
almost one-fourth
Integrated Coastal Management
Community-based group to
prevent further degradation of the
ocean
Estimating and Monitoring Fishery
Populations Is the First Step
Maximum sustained yield (MSY): traditional
approach
Optimum sustained yield (OSY)
Multispecies management
Large marine systems: using large complex
computer models
Precautionary principle
Some Countries Use the
Marketplace to Control Overfishing
Individual transfer rights (ITRs)
Control access to fisheries
New Zealand and Iceland
Difficult to enforce
Problems with the ITR approach
Consumer Choices Can Help to Sustain
Fisheries and Aquatic Biodiversity
1997: Marine Stewardship Council
(MSC), London
Supports sustainable fishing
Certifies sustainably produced seafood
Manage global fisheries more
sustainably
Individuals
Organizations
Governments
Monteray Bay Aquarium
Pocket guide for sustainable
fishing
Coastal and Inland Wetlands Are
Disappearing around the World
Highly productive wetlands
Provide natural flood and erosion control
Maintain high water quality; natural filters
Effect of rising sea levels
Laws for protection
Mitigation banking
Ecologists argue this as a last resort
Why are wetlands
threatened?
Many wetlands have been drained
and cleared for farms, housing
and commercial, coastal
development.
Most states now have laws
prohibiting the destruction of
wetlands.
FRESHWATER ECOSYSTEMS
ARE UNDER
MAJOR THREATS
Think: HIPPCO
We Can Protect Freshwater
Ecosystems by Protecting Watersheds
Freshwater ecosystems protected
through
Laws
Economic incentives
Restoration efforts
Wild rivers and scenic rivers
Sustainable management of freshwater
fishes
40% of rivershave been dammed or
engineered
RESTORING THE EVERGLADES
In order to meet growing population
needs, the Everglades has been drained,
paved over, invaded by plants… now less
than ½ its original size
90% of wading birds
have disappeared and
other populations
have decreased 75-95%
snail kite, manatee and panther
FLORIDA KEYS AND THE
FLORIDA BAY
Much of the water has been diverted
for crops and cities
Algal blooms
Coral reefs, diving, fishing, and
tourism have been affected
CERP
(Comprehensive
Everglades
Restoration Plan)
GREAT LAKES
Largest body of fresh water
Home to 162 invasive species
(sea lamprey, zebra mussels,
quagga mussel)
Case study:
LAKE VICTORIA
Human impacts have contributed
to: habitat loss, spread of an
invasive species, pollution, climate
change, depletion of commercially
valuable fish populations
LAKE VICTORIA
Located in East Africa- source of
the Nile River
Early 1980s= 500 species of fish
found nowhere else. Most were
cichlids which feed on detritus,
algae and zooplankton
Since 1980s= more than 200
species have become extinct
CAUSE OF THE EXTINCTIONS
Deliberately introduction of the
Nile perch- big fish with big
appetite
Frequent algal blooms caused
by nutrient runoff from farms,
deforestation (needed to smoke the
perch), and spills of untreated
sewage
Nile perch population is declining
now due to lack of food and being
overfished
PRIORITIES FOR PROTECTING
BIODIVERSITY, ECOSYSTEM SERVICES
2002: Edward O. Wilson
Complete the mapping of the world’s terrestrial
and aquatic biodiversity
Keep old-growth forests intact; cease their
logging
Identify and preserve hotspots and
deteriorating ecosystem services that threaten life
Ecological restoration projects
Make conservation financially rewarding
THE END
Adapted from
Ms. J. Root’s
power point
Elements
Page