Transcript Core Case Study: A Biological Roller Coaster Ride in Lake

Sustaining Aquatic Biodiversity
G. Tyler Miller’s
Living in the Environment
12th Edition
Chapter 24
Dr. Richard Clements
Chattanooga State Technical Community College
Key Concepts
 Economic and ecological importance
 Effects of human activities
 Protecting and sustaining aquatic diversity
 Protecting and sustaining fisheries
 Protecting and restoring wetlands
Core Case Study: A Biological Roller
Coaster Ride in Lake Victoria
• Lake Victoria has lost their endemic fish
species to large introduced predatory fish.
Figure 12-1
Core Case Study: A Biological
Roller Coaster Ride in Lake
Victoria
• Reasons for Lake Victoria’s loss of
biodiversity:
– Introduction of Nile perch.
– 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.
The Importance of Aquatic
Biodiversity
Highest diversity?
 Coral reefs
 Estuaries
 Deep ocean floor
Ecological and Economic services




Food items
Many chemicals
Medicines and drugs
Freshwater
Human Impacts on Aquatic
Biodiversity
 Species loss and endangerment
 Marine habitat loss and degradation
 Freshwater habitat loss and degradation
 Lost ~1/2 of wetlands
 1/4 of coral reefs damaged
 1/3 of mangrove forests gone
 Many bottom habitats degraded by dredging
and trawlers.
Human Impacts on Aquatic
Biodiversity
 Overfishing
 3/4 of valuable marine species overfished
 Leads to commercial extinction
 bycatch
 Nonnative species
 Ballast water
 Asian swamp eel
 Purple loosestrife
 Zebra mussels
 Pollution and global warming
Fish farming
in cage
Trawl flap
Trawler
fishing
Spotter airplane
Sonar
Purse-seine fishing
Trawl
lines
Trawl bag
Long line
fishing
Fish
school
Drift-net fishing
Float Buoy
Lines with
hooks
Deep sea
aquaculture cage
Fish caught
by gills
Fig. 12-A, p. 255
Population Growth and
Pollution
• Each year plastic
items dumped
from ships and left
as litter on beaches
threaten marine
life.
Figure 12-3
Protecting and Sustaining Marine
Biodiversity
 Protect endangered and threatened species
 Sea turtles, marine mammals, etc…
 Establish protected areas
 ~1300 existing MPAs
 Integrated coastal management
 Groups competing for resources identify shared
problems and goals
 Regulating and preventing ocean pollution
 Sustainable management of marine fisheries
PROTECTING AND SUSTAINING
MARINE BIODIVERSITY
• Six of the world’s
seven major turtle
species are
threatened or
endangered
because of human
activities.
Figure 12-4
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
Figure 12-B
Case Study: Commercial
Whaling
• After many of the
world’s whale
species were
overharvested,
commercial
whaling was
banned in 1960,
but the ban may be
overturned.
Figure 12-6
Case Study:
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.
Figure 12-5
Managing and Sustaining the
World’s Marine Fisheries
Fishery regulations
Economic approaches
Bycatch reduction
Protected areas
Nonnative species
Consumer information
Aquaculture
Protecting, Sustaining, and
Restoring Wetlands
Regulations
Kissimmee
River
Mitigation banking
Land use planning
Wetlands restoration
Control of invasive
species
Channelized
(
)
Unchannelized
(
)
FLORIDA
Fort Myers
GULF OF
MEXICO
Lake
Okeechobee
West
Palm
Beach
Naples
Fort
Lauderdale
Agricultural area
Treatment marsh
Water
conservation area
Canal
FLORIDA
Miami
Everglades
National
Park
Florida Bay
Area of
detail
0
20
ATLANTIC
OCEAN
Key Largo
40
60 miles
0 20 40 60 kilometers
Protecting, Sustaining, and
Restoring Lakes
Pollution
Invasive species
Water levels
Cultural
eutrophication
Protecting, Sustaining, and
Restoring Rivers
Pollution
Disruption of
water flow
Loss of
biodiversity
Invasive species