Population Growth and Pollution Can Reduce Aquatic Biodiversity

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APES Chapter 11: Day 1
 Objectives
• Describe HIPPCO
• List the threats to
aquatic life
 Agenda
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•
•
•
•
Warm-up – 5
HIPPCO notes – 10
Strange Days – 10
HIPPCO Notes – 10
Computer Lab
Homework:
Chapter 11 Objectives
 Warm-up
1. What is the
epilimnion?
Hypolimnion?
2. How does the
temperature of
each change with
season?
Sustaining Aquatic Biodiversity
Chapter 11
Core Case Study: A Biological Roller
Coaster Ride in Lake Victoria
 Shallow lake in East
Africa
• 500 species of fish found
nowhere else
 Nile perch: deliberately
introduced
• Loss of biodiversity and
cichlids (“SIK-lids”)
• Increased poverty and
malnutrition
• Depleted forests (to
preserve fish oil)
Core Case Study: A Biological Roller
Coaster Ride in Lake Victoria
 Frequent algal
blooms
• Nutrient runoff
• Spills of untreated
sewage
• Less algae-eating
cichlids
11.1
What are the major threats to
aquatic biodiversity?
We Have Much to Learn about
Aquatic Biodiversity
 Greatest marine biodiversity
• Coral reefs
• Estuaries
• Deep-ocean floor
We have
explored 5% of
the global
ocean!
 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
H
I
P
P
C
O
• Marine
• Coastal pollution and
tourism
• Ocean floor: effect of
trawlers
• Freshwater
• Dams
• Excessive water
withdrawal
Science Focus: Protecting and
Restoring Mangroves
 Protect and restore
mangroves
• Reduce the impact of
rising sea levels
• Protect against tropical
storms and tsunamis
• Cheaper than building
concrete sea walls
• Mangrove forests in
Indonesia
Natural Capital Degradation: Area of Ocean
Bottom Before and After a Trawler
Invasive Species Are Degrading
Aquatic Biodiversity
 Invasive species
H
I
P
P
C
O
• Threaten native
species
• Disrupt and degrade
whole ecosystems
• 84% of world’s coasts
are being colonized by
invasive species
Invasive Species Are Degrading
Aquatic Biodiversity
 Three examples
H
I
P
P
C
O
• 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 leafeating beetle—Will it
work?
Science Focus: How Carp Have Muddied
Some Waters
 Lake Wingra, Wisconsin
(U.S.): eutrophic
• Contains invasive species
• Purple loosestrife and the
common carp increase
turbidity
 Dr. Richard Lathrop
• Removed carp from an
area of the lake
• This area appeared to
recover
• More photosynthesis
Population Growth and Pollution Can
Reduce Aquatic Biodiversity
 Nitrates and
phosphates mainly
H from fertilizers enter
I water
P
P
C
O
• Leads to
eutrophication
Toxic pollutants from
industrial and urban
areas
Population Growth and Pollution Can
Reduce Aquatic Biodiversity
 Nitrates and
phosphates mainly
H from fertilizers enter
I water
P
P
C
O
• Leads to
eutrophication
Toxic pollutants from
industrial and urban
areas
Climate Change Is a Growing Threat
 Global warming: sea
levels will rise and
H aquatic biodiversity is
I threatened
P
P
C
O
• Coral reefs
• Swamp some lowlying islands
• Drown many highly
productive coastal
wetlands
• New Orleans,
Louisiana, and New
York City
Video Clip
 Strange Days on Planet Earth – Dirty Secrets
• Bleaching the Reef
Overfishing and Extinction: Gone
Fishing, Fish Gone
 Marine and freshwater fish
H
I
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P
C
O
• Threatened with extinction by human activities
more than any other group of species
• Modern industry can cause 80% depletion of
target species in 10-15 years
Commercial extinction – occurs when it is no
longer profitable to continue fishing an affected
species
Overfishing and Extinction: Gone
Fishing, Fish Gone
H
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P
C
O
 Bycatch – nontarget
species caught in fishing
• Comprises almost 1/3 of
world’s annual fish catch
Case Study: Industrial Fish Harvesting
Methods
 Trawler fishing
• Dragging funnel shaped
nets held open at the neck
along ocean bottom
• Weighted down with chains
or metal plates
• Newer nets are large
enough to swallow 12
jumbo jet planes!
• Catch shrimp, cod,
flounder, and scallops
Case Study: Industrial Fish Harvesting
Methods
 Purse-seine fishing
• Spotter plane locates
school of fish
• Vessel encloses it with
large net
• Catch surface dwelling
species (tuna,
mackerel, anchovies,
and herring)
• Dolphins frequent
bycatch
Case Study: Industrial Fish Harvesting
Methods
 Longlining
• Putting out lines up to 80 miles long with baited
hooks
• Adjustable depths
• Frequent bycatch (sea turtles and seabirds)
Case Study: Industrial Fish Harvesting
Methods
 Drift-net fishing
• Fish caught by huge
drifting nets
• Hang as deep as 50
feet below surface
• Extend 40 miles long
• 1992 UN ban on use
of nets longer than 1.6
miles
Major Commercial Fishing Methods Used
to Harvest Various Marine Species
11.2
11-2 How Can We Protect and Sustain
Marine Biodiversity?
 Concept 11-2 We can help to sustain marine
biodiversity by using laws and economic
incentives to protect species, setting aside
marine reserves to protect ecosystems, and
using community-based integrated coastal
management.
Legal Protection of Some Endangered
and Threatened Marine Species
 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
Case Study: Protecting Whales: A
Success Story… So Far
 Cetaceans: Toothed
whales and baleen
whales
• Bite and chew food vs.
filter feeders
 1970: U.S.
• Stopped all commercial
whaling
• Banned all imports of
whale products
 1986: moratorium on
commercial whaling
• Pros? Cons?
Tourism…
Norwegian Whalers Harpooning a
Sperm Whale
Examples of Cetaceans
Examples of Cetaceans
Individuals Matter: Creating an Artificial
Coral Reef in Israel
 Reuven Yosef, Red
Sea Star Restaurant
• Coral reef restoration
• Reconciliation ecology
• Treatment of broken
coral with antibiotics
Case Study: 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
Marine Sanctuaries Protect Ecosystems
and Species
 Offshore fishing
• A country’s offshore fishing zone extends 20
statute miles from its shores
• Exclusive economic zones – foreign ships may
extend into foreign waters when given
governmental permission
• High seas – free for all!
 Law of the Sea Treaty – coastal nations have
jurisdiction over 36% of ocean surface and 90%
fish stocks
Marine Sanctuaries Protect Ecosystems
and Species
 Marine Protected Areas (MPAs) – areas of
ocean partially protected from human activities
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•
•
•
4, 000 nationwide
200 US
Only partially protected
Harmful human activities still illegally occur
Establishing a Global Network of Marine
Reserves: An Ecosystem Approach
 Marine reserves – fully protected!
• Closed to
• Commercial fishing
• Dredging
• Mining and waste disposal
• Core zone
• No human activity allowed
• Less harmful activities allowed
• E.g., recreational boating and shipping
Establishing a Global Network of Marine
Reserves: An Ecosystem Approach
 Fully protected marine reserves work fast
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Fish populations double
Fish size grows
Reproduction triples
Species diversity increase by almost one-fourth
An Atoll of Australia’s Great Barrier Reef
11.3
11-3 How Should We Manage and Sustain
Marine Fisheries?
 Concept 11-3 Sustaining marine fisheries will
require improved monitoring of fish populations,
cooperative fisheries management among
communities and nations, reduction of fishing
subsidies, and careful consumer choices in
seafood markets.
Estimating and Monitoring Fishery
Populations Is the First Step
 Maximum sustained yield (MSY): traditional
approach; maximum amount of fish that can be
harvested annually without causing a population
drop
• Difficult to estimate population size and growth
rate
 Optimum sustained yield (OSY): takes into
account interactions among species
Estimating and Monitoring Fishery
Populations Is the First Step
 Multispecies management: also incorporates
competitive and predator-prey interactions
 Large marine systems: using large complex
computer models
 **Precautionary principle: sharply reducing fish
harvest and closing some overfished areas until
they recover
• Need more information about what levels of
fishing can be sustained
Government Subsidies Can Encourage
Overfishing
 2007: World Trade Organization, U.S.
• Proposed a ban on fishing subsidies
 Reduce illegal fishing on the high seas and in
coastal waters
• Close ports and markets to such fishers
• Check authenticity of ship flags
• Prosecution of offenders
Some Countries Use the Marketplace to
Control Overfishing
 Individual transfer rights (ITRs)
• Control access to fisheries
• Government gives each fishing vessel owner a
specified percentage of total allowable catch
(TAC) for a give year
• New Zealand and Iceland
• Difficult to enforce
 Problems with the ITR approach
• Illegally exceeding quotas
• Difficult to enforce
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
Solutions: Managing Fisheries
Video Clip
 Strange Days on Planet Earth: Baboons
11.4
11-4 How Should We Protect and
Sustain Wetlands?
 Concept 11-4 To maintain the ecological and
economic services of wetlands, we must
maximize preservation of remaining wetlands
and restoration of degraded and destroyed
wetlands.
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
We Can Preserve and Restore Wetlands
 Laws for protection
 Mitigation banking
• Ecologists argue this as a last resort
Natural Capital Restoration: Wetland
Restoration in Canada
Individuals Matter: Restoring a Wetland
 Jim Callender: 1982
 Scientific knowledge + hard work =
a restored wetland in California, U.S.
 Marsh used again by migratory fowl
Case Study: Can We Restore the Florida
Everglades? (1)
 “River of Grass”: south Florida, U.S.
 Since 1948: damaged
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Drained
Diverted
Paved over
Nutrient pollution from agriculture
Invasive plant species
 1947: Everglades National Park unsuccessful
protection project
Case Study: Can We Restore the Florida
Everglades? (2)
 1970s: political haggling
 1990: Comprehensive Everglades Restoration
Plan (CERP)
• Restore the curving flow of most of the
Kissimmee River
• Remove canals and levees in strategic locations
• Flood 240 sq. km farmland to create artificial
marshes
• Goal?
Case Study: Can We Restore the Florida
Everglades? (3)
 Comprehensive Everglades Restoration Plan
(CERP) cont…
• Create reservoirs and underground water storage
areas
• Build new canals, reservoirs and efficient
pumping systems
 Why isn’t this plan working?
The World’s Largest Restoration Project
11-5 How Can Protect and Sustain
Freshwater Lakes, Rivers, and Fisheries?
 Concept 11-5 Freshwater ecosystems are
strongly affected by human activities on adjacent
lands, and protecting these ecosystems must
include protection of their watersheds.
Freshwater Ecosystems Are under
Major Threats
 Think: HIPPCO
Case Study: Can the Great Lakes Survive
Repeated Invasions by Alien Species?
 Collectively, world’s largest body of freshwater
 Invaded by at least 162 nonnative species
• Sea lamprey
• Zebra mussel
• Good and bad
• Quagga mussel
• Asian carp
Zebra Mussels Attached to a Water
Current Meter in Lake Michigan, U.S.
Managing River Basins Is Complex
and Controversial
 Columbia River: U.S. and Canada
• Dam system
• Pros and cons
 Snake River: Washington state, U.S.
• Hydroelectric dams
• Pros and cons
Natural Capital: Ecological Services
of Rivers
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
Video: Salmon swimming upstream
11-6 What Are the Priorities for Sustained
Biodiversity, Ecosystem Services?
 Concept 11-6 Sustaining the world’s
biodiversity and ecosystem services will require
mapping terrestrial and aquatic biodiversity,
maximizing protection of undeveloped terrestrial
and aquatic areas, and carrying out ecological
restoration projects worldwide.
We Need to Set 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
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