Transcript Document
Sustaining Aquatic Biodiversity
G. Tyler Miller’s
Living in the Environment
13th Edition
Chapter 24
Key Concepts
Economic and ecological importance
Effects of human activities
Protecting and sustaining aquatic diversity
Protecting and sustaining fisheries
Protecting and restoring wetlands
Case Study: A Biological Roller
Coaster Ride in Lake Victoria
• Lake Victoria has lost its endemic fish
species to large introduced predatory
fish.
A Biological Roller Coaster Ride in
Lake Victoria
Reasons for Lake Victoria’s loss of
biodiversity:
• Introduction of Nile perch.
• Loss of native cichlid species
• Lake experienced algal blooms from nutrient
runoff.
• Invasion of water hyacinth has blocked
sunlight and deprived oxygen.
• Nile perch is in decline because it has eaten
its own food supply.
AQUATIC BIODIVERSITY
• We know fairly little about the
biodiversity of the world’s marine and
freshwater systems.
• The world’s marine and freshwater
systems provide important ecological
and economic services.
The Importance of Aquatic Biodiversity
• The most
biologically
diverse habitats
include:
–
–
–
–
Coral reefs
Estuaries
Deep ocean floor
Highest near the
coast
– 25,000 known fish
species
The Importance of Aquatic Biodiversity:
Ecological and Economic
• Food Items
– 6% of total protein; 16% of
animal protein
• Many Chemicals
– Cosmetics
• from seaweed
– Medicines and Drugs
• Antibiotics and
anticancer drug,
adhesives, bone
reconstructive
materials
• seaweed, sponges,
mollusks, coral
barnacles, and other
fish
APES Bell Ringer 11/28/2012
• What are 4 human impacts on aquatic
biodiversity?
Human Impacts on Aquatic
Biodiversity
• Species loss and endangerment
• Marine habitat loss and degradation
• Freshwater habitat loss and
degradation
• Overfishing
• Nonnative species
• Pollution and global warming
Species Loss and Endangerment
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Overfishing
Habitat destruction
Pollution
Freshwater species at greater risk
– Mussels, crayfish, amphibians, fish
Marine Habitat Loss and
Degradation
• 53% of coastal wetlands in US have
disappeared
– Agriculture
– Coastal development
• 58% of world’s coral reefs are threatened
– Coastal development
– Pollution
– Warmer ocean temperatures
• Two-thirds of US estuaries are at risk
from pollution
• 35% of world’s mangroves have
disappeared
Freshwater Habitat Loss and
Degradation
• The world has lost more than half of its
inland wetlands
– Agricultural and urban development
• 60% of the world’s larger rivers are
fragmented by dams, diversions, and
canals
• Flood control levees and dikes
– Alter and destroy aquatic habitats
– Disconnect rivers from their floodplains
– Eliminate wetlands and backwaters
(spawning areas)
Overfishing
• 75% of the world’s 200 commercially
valuable marine fish species are
overfished
• Overfishing leads to commercial
extinction
• Depletions and extinction of species
unintentionally caught as bycatch
Non-native Species
• Deliberate or accidental introduction into
coastal waters, lakes and wetlands
– purple loosestrife
– Asian swamp eel
– zebra mussle
• Displace or cause extinction of native
species
– 68% of fish extinctions
Pollution and Global Warming
• 44% comes from runoff from developed
coastal areas
• Major pollution threats • Global warming could
– Oil
– alter migration and
feeding patterns
– Acid deposition
– Plant nutrients
– increase ocean
temperature
– Toxic chemicals
– Coastal development
– raise sea levels
– Sediment and soil
erosion
PROTECTING AND SUSTAINING
MARINE BIODIVERSITY
• Six of the
world’s seven
major turtle
species are
threatened or
endangered
because o
human
activities.
Figure 12-4
Protect endangered and threatened
species
• Example: Sea turtle
– Turtle extrusion devices (TEDs)
Olive ridley
Loggerhead
Leatherback
Hawksbill
Australian
flatback
Black turtle
Green turtle
Kemp's
Ridley
Shrimp trawler
Turtle Extrusion
Device
Area enlarged right
Case Study: The Florida Manatee
and Water Hyacinths
• Manatee can eat unwanted
Water Hyacinths.
• Endangered due to:
– Habitat loss.
– Entanglement from
fishing lines and nets.
– Hit by speed boats.
– Stress from cold.
– Low reproductive rate
Case Study: Commercial
Whaling
• After many of the
world’s whale
species were
over-harvested,
commercial
whaling was
banned in 1960,
but the ban may
be overturned.
Commercial Whaling
• Despite ban, Japan,
Norway, and Iceland
kill about 1,300 whales
of certain species for
“scientific purposes”.
– Although meat is still
sold commercially.
Key Concepts
Economic and ecological importance
Effects of human activities
Protecting and sustaining aquatic diversity
Protecting and sustaining fisheries
Protecting and restoring wetlands
Protecting and Sustaining Marine
Biodiversity
• Identifying and protecting endangered
and threatened species
– Sea turtles
• Turtle extrusion devices (TEDs)
• National and International laws and
treaties
• CITES - Convention on International Trade and
Endangered Species
• Global Treaty on Migratory Species
• US Marine Mammal Protection Act
• US Endangered Species Act
• US Whale Conservation and Protection Act
• International Convention on Biological Diversity
Protecting and Sustaining Marine
Biodiversity
• Establish marine protected areas
– Coastal nations have sovereignty over
waters and seabeds up to 12 miles
offshore
– Jurisdiction over their Exclusive
Economic Zone extends 200 miles
offshore
• Integrated coastal management
– community based attempt to develop
and use coastal resources sustainably
Protecting and Sustaining Marine
Biodiversity
• Regulating and preventing ocean
pollution
• Sustaining management of marine
fisheries
Managing and Sustaining the
World’s Marine Fisheries
• Fishery regulation
– Set, monitor, and enforce fishery catch limits
below estimated MSY (maximum sustained yield)
– Divide up fishing quotas
– Require selective gear
– Improve monitoring and enforcement
• Economic approached
– Reduce or eliminate subsidies
– Impose fees for harvesting fish and shellfish from
public managed offshore waters
– Certify sustainable fisheries
Managing and Sustaining the
World’s Marine Fisheries
• Bycatch reduction
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Wider mesh fish nets
Extrusion devices
Observers on boats
Multiple species licensing
Laws prohibiting throwing edible and
marketable fish back to sea
Managing and Sustaining the
World’s Marine Fisheries
• Protected areas
– Establish no-fishing marine areas
– Protect marine habitats that are in good
condition and disregard potentially hopeless
cases
– Strengthen commitment to marine biodiversity
protection
• Non-native invasions
– Kill organisms in ship ballast water
– Develop filters and traps
– Require ships to dump ballast water beyond 200
mile limit
Managing and Sustaining the
World’s Marine Fisheries
• Consumer information
– Use labeling to identify fish that have been
harvested sustainably
• Aquaculture
– Restrict location of fish farms to reduce
loss of mangrove forests
– Enact and enforce stricter pollution
regulations
– Increase productions of herbivorous
aquaculture fish species
Protecting, Sustaining, and
Restoring Wetlands
• Regulations
– federal permit required
• Mitigation banking
– allows destruction of existing wetlands if an equal area of
they same type of wetland is created or restored
• Land use planning
– steer agriculture and mining away from wetlands
• Wetland restoration
– often has limited success
• Control of invasive species
– purple loosestrife
Restoring the Florida Everglades
• Natural flow of the
Everglades has been
diverted or disrupted.
• Farmers planted vast
agricultural land to
sugarcane and vegetables.
• Established Everglades
National Park. Became the
most endangered park.
• Massive plumbing and land
development projects cut
off water flow
Restoring the Florida Everglades
• 1990 began the world’s
largest ecological
restoration project.
– restore he curving flow of
more than half of the
Kissimmee River.
– remove 400 km of canals and
levees
– create artificial marshes in
previous farmland
– add land adjacent to
Everglades National Park
– create network of artificial
marshes
– create 18 large reservoirs
– capture much of the water
flowing out to sea and return it
to the Everglades
Protecting, Sustaining, and
Restoring Wetlands
Protecting, Sustaining, and
Restoring Lakes
Pollution
Cultural
eutrophication
Water levels
Invasive species
Zebra mussel
Protecting, Sustaining, and
Restoring Rivers
Pollution
Disruption of
water flow
Loss of
biodiversity
Invasive
species
Protecting, Sustaining, and
Restoring Rivers
Disruption of water flow
119 dams,
19 hydroelectric dams
Salmon population
dropped 94%
Salmon Restoration
Project
upstream hatcheries
fish ladders
transport juveniles
around dams
turning off turbines
PROTECTING, SUSTAINING, AND
RESTORING LAKES AND RIVERS
• We can help sustain freshwater fisheries by
building and protecting populations of
desirable species, preventing over-fishing,
and decreasing populations of less
desirable species.
• A federal law helps protect a tiny fraction of
U.S. wild and scenic rivers from dams and
other forms of development.
– National Wild and Scenic Rivers Act
(1968).