Sustaining Aquatic Biodiversity. Core Case Study: A Biological Roller Coaster Ride in Lake Victoria Lake Victoria has lost their endemic fish species.

Sustaining Aquatic Biodiversity

Core Case Study: A Biological Roller Core Case Study: A Biological Roller Coaster Ride in Lake VictoriaCoaster Ride in Lake Victoria

Lake Victoria has lost their endemic fish Lake Victoria has lost their endemic fish species to large introduced predatory fish.species to large introduced predatory fish.

Figure 12-1Figure 12-1

Core Case Study: A Biological Roller Core Case Study: A Biological Roller Coaster Ride in Lake VictoriaCoaster Ride in Lake Victoria

Reasons for Lake Victoria’s loss of Reasons for Lake Victoria’s loss of biodiversity:biodiversity: Introduction of Nile perch.Introduction of Nile perch. Lake experienced algal blooms from nutrient Lake experienced algal blooms from nutrient

runoff.runoff. Invasion of water hyacinth has blocked sunlight Invasion of water hyacinth has blocked sunlight

and deprived oxygen.and deprived oxygen. Nile perch is in decline because it has eaten its Nile perch is in decline because it has eaten its

own food supply.own food supply.

Three General Patterns of Marine Three General Patterns of Marine BiodiversityBiodiversity

The greatest marine biodiversity occurs in coral The greatest marine biodiversity occurs in coral reefs, estuaries, and the deep-ocean floorreefs, estuaries, and the deep-ocean floor

Biodiversity is higher near coasts than in the open Biodiversity is higher near coasts than in the open sea because of the greater variety of producers and sea because of the greater variety of producers and habitats in coastal areashabitats in coastal areas

Biodiversity is higher in the bottom region of the Biodiversity is higher in the bottom region of the ocean than in the surface region because of the ocean than in the surface region because of the greater variety of habitats and food sources on the greater variety of habitats and food sources on the ocean bottomocean bottom

HUMAN IMPACTS ON AQUATIC HUMAN IMPACTS ON AQUATIC BIODIVERSITYBIODIVERSITY

Human activities have destroyed, disrupted Human activities have destroyed, disrupted or degraded a large proportion of the world’s or degraded a large proportion of the world’s coastal, marine and freshwater ecosystems.coastal, marine and freshwater ecosystems. Approximately 20% of the world's coral reefs Approximately 20% of the world's coral reefs

have been destroyed.have been destroyed. During the past 100 years, sea levels have risen During the past 100 years, sea levels have risen

10-25 centimeters.10-25 centimeters. We have destroyed more than 1/3 of the world’s We have destroyed more than 1/3 of the world’s

mangrove forests for shipping lanes.mangrove forests for shipping lanes.

Shrimp farms in areas that were once mangrove

forests

Additional ways humans degrade our ocean

environment

HUMAN IMPACTS ON AQUATIC HUMAN IMPACTS ON AQUATIC BIODIVERSITYBIODIVERSITY

Area of ocean before and after a trawler net, Area of ocean before and after a trawler net, acting like a giant plow, scraped it.acting like a giant plow, scraped it.

Figure 12-2Figure 12-2

HUMAN IMPACTS ON AQUATIC HUMAN IMPACTS ON AQUATIC BIODIVERSITYBIODIVERSITY

Harmful invasive species are an increasing Harmful invasive species are an increasing threat to marine and freshwater biodiversity.threat to marine and freshwater biodiversity. Bioinvaders are blamed for about 2/3 of fish Bioinvaders are blamed for about 2/3 of fish

extinctions in the U.S. between 1900-2000.extinctions in the U.S. between 1900-2000. Almost half of the world’s people live on or Almost half of the world’s people live on or

near a coastal zone and 80% of ocean water near a coastal zone and 80% of ocean water pollution comes from land-based human pollution comes from land-based human activities.activities.

Asian Rice Eel

Population Growth and PollutionPopulation Growth and Pollution Each year plastic items Each year plastic items

dumped from ships and dumped from ships and left as litter on beaches left as litter on beaches threaten marine life.threaten marine life.

It’s just a plastic bag! It can’t hurt anyone.

Sea turtle off the coast of Florida

What can you do to make sure this does

not continue?

Overfishing and Extinction: Overfishing and Extinction: Gone Fishing, Fish GoneGone Fishing, Fish Gone

About 75% of the world’s commercially About 75% of the world’s commercially valuable marine fish species are over fished valuable marine fish species are over fished or fished near their sustainable limits.or fished near their sustainable limits. Big fish are becoming scarce.Big fish are becoming scarce. Smaller fish are next.Smaller fish are next. We throw away 30% of the fish we catch.We throw away 30% of the fish we catch. We needlessly kill sea mammals and birds.We needlessly kill sea mammals and birds.

Human impacts on marine biodiversity• Coral reef destruction• Sea level rising• Destruction of mangrove forests• Trawler nets destroying ocean floor• Invasive species• Coastal development• Trash• Overfishing

Industrial fish harvesting methodsIndustrial fish harvesting methods

Trawler fishing: dragging net along ocean floorTrawler fishing: dragging net along ocean floor

Purse-seine fishing: surround fish with netPurse-seine fishing: surround fish with net

Long-line fishing: 80 miles of fishing line with Long-line fishing: 80 miles of fishing line with thousands of baited hooksthousands of baited hooks

Drift-net fishing: 80 miles of drifting nets below the Drift-net fishing: 80 miles of drifting nets below the surfacesurface

Problems with industrial fish harvesting Problems with industrial fish harvesting methodsmethods

Trawler fishing: like clear-cutting forest; destroys Trawler fishing: like clear-cutting forest; destroys ocean floor; captures endangered seals and turtlesocean floor; captures endangered seals and turtles

Purse-seine fishing: kills hundreds of dolphinsPurse-seine fishing: kills hundreds of dolphins

Long-line fishing: hooks endangered sea turtles, Long-line fishing: hooks endangered sea turtles, albatross, pilot whales, sharks, dolphinsalbatross, pilot whales, sharks, dolphins

Drift-net fishing: kills non-target fish species and Drift-net fishing: kills non-target fish species and marine mammalsmarine mammals

Fig. 12-A, p. 255

Fish farming in cage

Trawler fishing

Spotter airplane

Sonar

Trawl flap

Trawl lines

Purse-seine fishing

Trawl bagFish school

Drift-net fishingLong line fishing

Lines with hooks

Fish caught by gills

Deep sea aquaculture cage

Float Buoy

Trawler fishing

By-catch

Purse-seine fishing

Long-line fishing

Several countries have banned the use of drift nets or they

are carefully monitoring the use of

drift nets

Drift-nets catch and

kill anything caught in

its net

Why is it Difficult to Protect Aquatic Why is it Difficult to Protect Aquatic Biodiversity?Biodiversity?

Rapid increasing human impacts, the Rapid increasing human impacts, the invisibility of problems, citizen unawareness, invisibility of problems, citizen unawareness, and lack of legal jurisdiction hinder protection and lack of legal jurisdiction hinder protection of aquatic biodiversity.of aquatic biodiversity. Human ecological footprint is expanding.Human ecological footprint is expanding. Much of the damage to oceans is not visible to Much of the damage to oceans is not visible to

most people.most people. Many people incorrectly view the oceans as an Many people incorrectly view the oceans as an

inexhaustible resource.inexhaustible resource.

PROTECTING AND SUSTAINING PROTECTING AND SUSTAINING MARINE BIODIVERSITYMARINE BIODIVERSITY

Laws, international treaties, and education Laws, international treaties, and education can help reduce the premature extinction of can help reduce the premature extinction of marine species.marine species.

Since 1989 the U.S. government has Since 1989 the U.S. government has required offshore shrimp trawlers to use turtle required offshore shrimp trawlers to use turtle exclusion devices (TEDs).exclusion devices (TEDs). Sea turtle tourism brings in almost three times as Sea turtle tourism brings in almost three times as

much money as the sale of turtle products.much money as the sale of turtle products.

PROTECTING AND SUSTAINING PROTECTING AND SUSTAINING MARINE BIODIVERSITYMARINE BIODIVERSITY

Six of the world’s Six of the world’s seven major turtle seven major turtle species are species are threatened or threatened or endangered endangered because of human because of human activities.activities.

Figure 12-4Figure 12-4

Laws and international treaties protecting Laws and international treaties protecting marine biodiversitymarine biodiversity

CITESCITES Global Treaty on Migratory SpeciesGlobal Treaty on Migratory Species Marine Mammal Protection ActMarine Mammal Protection Act ESAESA Whale Conservation and Protection ActWhale Conservation and Protection Act International Convention on Biological International Convention on Biological

DiversityDiversity

Exclusive Economic Zone

PROTECTING AND SUSTAINING PROTECTING AND SUSTAINING MARINE BIODIVERSITYMARINE BIODIVERSITY

Fully protected marine reserves make up less Fully protected marine reserves make up less than 0.3% of the world’s ocean area.than 0.3% of the world’s ocean area. Studies show that fish populations double, size Studies show that fish populations double, size

grows by almost a third, reproduction triples and grows by almost a third, reproduction triples and species diversity increases by almost one fourth.species diversity increases by almost one fourth.

Some communities work together to develop Some communities work together to develop integrated plans for managing their coastal integrated plans for managing their coastal areas.areas.

Integrated Coastal Management• Fisheries scientists• Conservationists• Citizens• Business interests• Developers• Politicians

Competing for the same resource – identify shared problems and goals and attempt to develop workable, cost-effective, and adaptable solutions that preserve biodiversity and environmental quality while meeting economic and social needs.

Revamping Ocean PolicyRevamping Ocean Policy

Two recent studies called for an overhaul of Two recent studies called for an overhaul of U.S. ocean policy and management.U.S. ocean policy and management. Develop unified national policy.Develop unified national policy. Double federal budget for ocean research.Double federal budget for ocean research. Centralize the National Oceans Agency.Centralize the National Oceans Agency. Set up network of marine reserves.Set up network of marine reserves. Reorient fisheries management towards Reorient fisheries management towards

ecosystem function.ecosystem function. Increase public awareness.Increase public awareness.

Fig. 12-7, p. 261

SolutionsManaging Fisheries

Fishery Regulations

Set catch limits well below the maximum sustainable yield

Improve monitoring and enforcement of regulationsEconomic Approaches

Sharply reduce or eliminate fishing subsidies

Charge fees for harvesting fish and shellfish from publicly owned offshore waters

Certify sustainable fisheriesProtected Areas

Establish no-fishing areas

Establish more marine protected areas

Rely more on integrated coastal management

Consumer Information

Label sustainably harvested fish

Publicize overfished and threatened species

Bycatch

Use wide-meshed nets to allow escape of smaller fish

Use net escape devices for sea birds and sea turtles

Ban throwing edible and marketable fish back into the sea

Aquaculture

Restrict coastal locations for fish farms

Control pollution more strictly

Depend more on herbivorous fish species

Nonnative Invasions

Kill organisms in ship ballast water

Filter organisms from ship ballast water

Dump ballast water far at sea and replace with deep-sea water

PROTECTING, SUSTAINING, AND PROTECTING, SUSTAINING, AND RESTORING WETLANDSRESTORING WETLANDS

Requiring government permits for filling or Requiring government permits for filling or destroying U.S. wetlands has slowed their destroying U.S. wetlands has slowed their loss, but attempts to weaken this protection loss, but attempts to weaken this protection continue.continue.

Figure 12-8Figure 12-8

Fig. 12-9, p. 264

Solutions

Protecting Wetlands

Legally protect existing wetlands

Steer development away from existing wetlands

Use mitigation banking only as a last resort

Require creation and evaluation of a new wetland before destroying an existing wetland

Restore degraded wetlands

Try to prevent and control invasions by nonnative species

Case Study: Case Study: Restoring the Florida EvergladesRestoring the Florida Everglades

The world’s largest ecological restoration The world’s largest ecological restoration project involves trying to undo some of the project involves trying to undo some of the damage inflicted on the Everglades by damage inflicted on the Everglades by human activities.human activities. 90% of park’s wading birds have vanished.90% of park’s wading birds have vanished. Other vertebrate populations down 75-95%.Other vertebrate populations down 75-95%. Large volumes of water that once flowed through Large volumes of water that once flowed through

the park have been diverted for crops and cities.the park have been diverted for crops and cities. Runoff has caused noxious algal blooms. Runoff has caused noxious algal blooms.

Restoring the Restoring the Florida Florida

EvergladesEverglades

The project has The project has been attempting been attempting to restore the to restore the Everglades and Everglades and Florida water Florida water supplies.supplies.

Figure 12-10Figure 12-10

PROTECTING, SUSTAINING, AND PROTECTING, SUSTAINING, AND RESTORING LAKES AND RIVERSRESTORING LAKES AND RIVERS

Lakes are difficult to manage and are Lakes are difficult to manage and are vulnerable to planned or unplanned vulnerable to planned or unplanned introductions of nonnative species.introductions of nonnative species.

For decades, invasions by nonnative species For decades, invasions by nonnative species have caused major ecological and economic have caused major ecological and economic damage to North America’s Great lakes.damage to North America’s Great lakes. Sea lamprey, zebra mussel, quagga mussel, Sea lamprey, zebra mussel, quagga mussel,

Asian carp. Asian carp.

PROTECTING, SUSTAINING, AND PROTECTING, SUSTAINING, AND RESTORING LAKES AND RIVERSRESTORING LAKES AND RIVERS

Dams can provide many human benefits but Dams can provide many human benefits but can also disrupt some of the ecological can also disrupt some of the ecological services that rivers provide.services that rivers provide. 119 dams on Columbia River have sharply 119 dams on Columbia River have sharply

reduced (94% drop) populations of wild salmon.reduced (94% drop) populations of wild salmon. U.S. government has spent $3 billion in U.S. government has spent $3 billion in

unsuccessful efforts to save the salmon.unsuccessful efforts to save the salmon. Removing hydroelectric dams will restore native Removing hydroelectric dams will restore native

spawning grounds.spawning grounds.

PROTECTING, SUSTAINING, AND PROTECTING, SUSTAINING, AND RESTORING LAKES AND RIVERSRESTORING LAKES AND RIVERS

We can help sustain freshwater fisheries by We can help sustain freshwater fisheries by building and protecting populations of building and protecting populations of desirable species, preventing over-fishing, desirable species, preventing over-fishing, and decreasing populations of less desirable and decreasing populations of less desirable species.species.

A federal law helps protect a tiny fraction of A federal law helps protect a tiny fraction of U.S. wild and scenic rivers from dams and U.S. wild and scenic rivers from dams and other forms of development.other forms of development. National Wild and Scenic Rivers Act (1968).National Wild and Scenic Rivers Act (1968).

Fig. 12-11, p. 267

• Deliver nutrients to sea to help sustain coastal fisheries

• Deposit silt that maintains deltas

• Purify water

• Renew and renourish wetlands

• Provide habitats for wildlife

Natural Capital

Ecological Services of Rivers

The End