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

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

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 ( ) 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

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