1. Sustaining Aquatic Biodiversity
G. Tyler Miller’s
Living in the Environment
12th Edition
Chapter 24
Dr. Richard Clements
Chattanooga State Technical Community College

2. Key Concepts Economic and ecological importance
Effects of human activities
Protecting and sustaining aquatic diversity
Protecting and sustaining fisheries
Protecting and restoring wetlands

3. 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

4. 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.

5. 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

6. 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.

7. 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

8. Deep sea aquaculture cage Fish caught by gills
Trawler fishing
Fish farming in cage
Spotter airplane
Sonar
Purse-seine fishing
Trawl flap
Trawl lines
Fish school
Trawl bag
Drift-net fishing
Long line fishing
Float
Buoy
Figure 12.A
Natural capital degradation: major commercial fishing methods used to harvest various marine species. These methods have become so effective that many fish species have become commercially extinct.
Lines with hooks
Deep sea aquaculture cage
Fish caught by gills
Fig. 12-A, p. 255

9. Population Growth and Pollution
Each year plastic items dumped from ships and left as litter on beaches threaten marine life.
Figure 12-3

10. 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

11. 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

12. 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

13. 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

14. 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

15. Managing and Sustaining the World’s Marine Fisheries
Fishery regulations
Economic approaches
Bycatch reduction
Protected areas
Nonnative species
Consumer information
Aquaculture

16. Protecting, Sustaining, and Restoring Wetlands
Regulations ( )
GULF OF
MEXICO
Naples
Fort Myers
FLORIDA
Florida Bay
Everglades
National
Park
Key Largo
ATLANTIC
OCEAN
Miami
Fort
Lauderdale
West
Palm
Beach
Lake
Okeechobee
Unchannelized
Channelized
Area of
detail
Agricultural area
Treatment marsh
Water
conservation area
Canal
miles
kilometers 20 40 60
Kissimmee
River
Mitigation banking
Land use planning
Wetlands restoration
Control of invasive species

17. Protecting, Sustaining, and Restoring Lakes
Pollution
Invasive species
Water levels
Cultural eutrophication

18. Protecting, Sustaining, and Restoring Rivers
Pollution
Disruption of water flow
Loss of biodiversity
Invasive species