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Chapter 11Chapter 11
Sustaining Aquatic Sustaining Aquatic BiodiversityBiodiversity
Mola Mola!
Chapter Overview QuestionsChapter Overview Questions
What do we know about aquatic biodiversity, and What do we know about aquatic biodiversity, and what is its what is its economiceconomic and and ecological ecological importance?importance?
How are How are human activitieshuman activities affecting aquatic affecting aquatic biodiversity?biodiversity?
How can we How can we protect and sustainprotect and sustain marinemarine biodiversitybiodiversity??
How can we How can we manage and sustainmanage and sustain the world’s the world’s marine marine fisheriesfisheries??
Chapter Overview Questions (cont’d)Chapter Overview Questions (cont’d)
How can we How can we protect, sustain, and restoreprotect, sustain, and restore wetlandswetlands??
How can we How can we protect, sustain, and restoreprotect, sustain, and restore lakes, rivers, and freshwater fisherieslakes, rivers, and freshwater fisheries??
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 many of its endemic Lake Victoria has lost many of its endemic fish species to large introduced predatory fish species to large introduced predatory fish, the fish, the Nile perch.Nile perch.
Figure 12-1Figure 12-1
Lake Victoria CichlidsLake Victoria Cichlids
Figure 12-1Figure 12-1
Astatotilapia latifasciata
About 200 of 400 Lake Victoria endemic cichlid species have become extinct since the introduction of the Nile perch.
Pundamilia nyererei
Haplochromis sp. 44 "Red Tail"
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 Introduction of Nile perchNile perch.. Lake experienced Lake experienced algal bloomsalgal blooms from from nutrient nutrient
runoff.runoff. InvasionInvasion of of water hyacinthwater hyacinth has blocked sunlight 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 (!)
AQUATIC BIODIVERSITYAQUATIC BIODIVERSITY
We know fairly littleWe know fairly little about the biodiversity of about the biodiversity of the world’s marine and freshwater systems.the world’s marine and freshwater systems.
We know more about deep spaceWe know more about deep space than the than the abyssal zones of the ocean (why?).abyssal zones of the ocean (why?). The greatest The greatest marine biodiversitymarine biodiversity occurs in occurs in coral coral
reefsreefs, , estuariesestuaries and the and the deep ocean floordeep ocean floor.. Biodiversity is higher near the Biodiversity is higher near the coast and surfacecoast and surface
because of because of habitathabitat and and food source varietyfood source variety.. The world’s marine and freshwater systems The world’s marine and freshwater systems
provide important provide important ecologicalecological and and economic economic services.services.
AQUATIC BIODIVERSITYAQUATIC BIODIVERSITY About About 50%50% of the of the
world’s people depend world’s people depend on the sea as their on the sea as their primary source of food.primary source of food.
Indonesian fishing prau
Lake Victoria fishers
Georgia shrimper
AQUATIC BIODIVERSITYAQUATIC BIODIVERSITY About About 90% of fish spawn90% of fish spawn in the world’s coral reefs, in the world’s coral reefs,
mangrove swampsmangrove swamps, coastal wetlands, or rivers., coastal wetlands, or rivers.
Coastal Wetlands: Salt marsh or Coastal Wetlands: Salt marsh or MangrovesMangroves
Coastal Wetlands: Salt marsh or Coastal Wetlands: Salt marsh or MangrovesMangroves
Coastal Wetlands: Salt marsh or Coastal Wetlands: Salt marsh or MangrovesMangroves
Snook!
Kayaking MangrovesKayaking Mangroves
Kayaking MangrovesKayaking Mangroves
Kayaking MangrovesKayaking Mangroves
HUMAN IMPACTS ON AQUATIC HUMAN IMPACTS ON AQUATIC BIODIVERSITYBIODIVERSITY
Human activities have Human activities have destroyed, disrupted destroyed, disrupted or degradedor degraded a large proportion of the world’s a large proportion of the world’s coastal, marine and freshwater ecosystems.coastal, marine and freshwater ecosystems. Approximately Approximately 20% of the world's coral reefs20% 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
1.0-2.5 centimeters.1.0-2.5 centimeters. We have destroyed more than We have destroyed more than 1/3 of the world’s 1/3 of the world’s
mangrove forests, mangrove forests, mostly mostly for for shipping lanesshipping lanes.. Shrimp farmingShrimp farming is a big, new threat to mangroves is a big, new threat to mangroves
Area of ocean before and after a Area of ocean before and after a trawler nettrawler net passed by. passed by.Note: East coast shrimp trawlers work in relatively open areas Note: East coast shrimp trawlers work in relatively open areas
and do not do this much damageand do not do this much damage
Figure 12-2Figure 12-2
HUMAN IMPACTS ON AQUATIC HUMAN IMPACTS ON AQUATIC BIODIVERSITYBIODIVERSITY
HUMAN IMPACTS ON AQUATIC HUMAN IMPACTS ON AQUATIC BIODIVERSITYBIODIVERSITY
Harmful invasive speciesHarmful invasive species are an increasing 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 halfAlmost half of the world’s people live on or of the world’s people live on or near a coastal zone and near a coastal zone and 80% of ocean water 80% of ocean water pollutionpollution comes from land-based human comes from land-based human activities.activities.
Population Growth and PollutionPopulation Growth and Pollution Each year Each year plasticplastic items items
dumped from ships and dumped from ships and washing in to the ocean washing in to the ocean from land threaten from land threaten marine life.marine life.
““Red tide”Red tide” is a toxic is a toxic algae bloom that is algae bloom that is exacerbatedexacerbated by excess by excess nutrients entering the nutrients entering the water from terrestrial water from terrestrial sourcessources Figure 12-3Figure 12-3
Population Growth and Pollution:Population Growth and Pollution:Excess NutrientsExcess Nutrients
Since 1860, humans Since 1860, humans have have doubled the flow doubled the flow of nitrogenof nitrogen, mostly as , mostly as nitrate fertilizers, into nitrate fertilizers, into the ocean.the ocean.
Figure 12-3Figure 12-3
N P K
NitrogenPotassium
“potash”Phosphorous
Overfishing and Extinction: Overfishing and Extinction: Gone Fishing, Fish GoneGone Fishing, Fish Gone
About About 75%75% of the world’s commercially of the world’s commercially valuable marine fish species are valuable marine fish species are over fishedover 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
(bycatch)(bycatch) We needlessly kill sea mammals and birds.We needlessly kill sea mammals and birds.
Overfishing and Extinction: Overfishing and Extinction: Gone Fishing, Fish GoneGone Fishing, Fish Gone
Commercial depletionCommercial depletion occurs when a species occurs when a species has been over fished to the point where it is has been over fished to the point where it is no longer profitable as a fishery.no longer profitable as a fishery.
Overfishing and Extinction: Overfishing and Extinction: Gone Fishing, Fish GoneGone Fishing, Fish Gone
Review! When too many people using the Review! When too many people using the same resource in a way that makes sense for same resource in a way that makes sense for them as individuals results in the collapse of them as individuals results in the collapse of the resource, it is called…the resource, it is called…
The Tragedy of the CommonsThe Tragedy of the Commons
Fig. 12-A, p. 255
Fish farming in cage
Trawler fishing
Spotter airplane
SonarTrawl flap
Trawl lines
Purse-seine fishing
Trawl bag
Fish school
Drift-net fishing a.k.a. gill netting
Long line fishing
Lines with hooks
Fish caught by gills
Deep sea aquaculture cage
Float Buoy
Why is it Difficult to Protect Aquatic Biodiversity?Why is it Difficult to Protect Aquatic Biodiversity? HumanHuman ecological footprint ecological footprint is increasing so is increasing so
rapidlyrapidly Much damage done to oceans is Much damage done to oceans is “invisible” “invisible” to to
most peoplemost people Most citizens are unaware Most citizens are unaware of the scope and of the scope and
severity of the problemsseverity of the problems Lack of Lack of legal jurisdictionlegal jurisdiction Many people Many people incorrectly viewincorrectly view the oceans as the oceans as
an an inexhaustible resource.inexhaustible resource.
PROTECTING AND SUSTAINING PROTECTING AND SUSTAINING MARINE BIODIVERSITYMARINE BIODIVERSITY
Laws, international treaties, and educationLaws, 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 required offshore shrimp trawlers to use turtle turtle exclusion devicesexclusion devices (TEDs) (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.
Turtle Excluder Devices (TEDs)Turtle Excluder Devices (TEDs)
Turtle Excluder Devices (TEDs)Turtle Excluder Devices (TEDs)
Turtle Excluder Devices (TEDs)Turtle Excluder Devices (TEDs)
Bycatch Reduction Devices (BRDs)Bycatch Reduction Devices (BRDs)
Bycatch Reduction Devices (BRDs)Bycatch Reduction Devices (BRDs)
PROTECTING AND SUSTAINING PROTECTING AND SUSTAINING MARINE BIODIVERSITYMARINE BIODIVERSITY
Six of the world’s seven Six of the world’s seven major turtle species are major turtle species are threatened or threatened or endangered because of endangered because of human activities.human activities.
*beach development*beach development
*harvesting eggs*harvesting eggs
*turtle shell jewelry*turtle shell jewelry
*leather made of flippers*leather made of flippers
Figure 12-4Figure 12-4
Case Study: The Florida Manatee and Case Study: The Florida Manatee and Water HyacinthsWater Hyacinths
Manatee can eat Manatee can eat unwanted Water unwanted Water Hyacinths.Hyacinths.
Endangered due to:Endangered due to: Habitat loss.Habitat loss. Entanglement from fishing Entanglement from fishing
lines and nets.lines and nets. Hit by speed boats.Hit by speed boats. Stress from cold.Stress from cold. Low reproductive rateLow reproductive rate
Figure 12-BFigure 12-B
Case Study: Commercial WhalingCase Study: Commercial Whaling
After many of the After many of the world’s whale world’s whale species were species were overharvested, overharvested, commercial commercial whaling was whaling was banned in 1960, banned in 1960, but the ban may but the ban may be overturned.be overturned.
Figure 12-6Figure 12-6
Japan has a significant whaling industry and whale meat market
Case Study: Case Study: Commercial WhalingCommercial Whaling
Despite ban, Japan, Despite ban, Japan, Norway, and Iceland kill Norway, and Iceland kill about 1,300 whales of about 1,300 whales of certain species for certain species for “scientific purposes”.“scientific purposes”. Although meat is still sold Although meat is still sold
commercially.commercially.
Figure 12-5Figure 12-5
Fig. 12-5, p. 258
Toothed whales *Sperm whale with squid
Killer whale
NarwhalBottlenose dolphin
Baleen whales
Blue whale
Fin whaleBowhead whale
Right whale
Sei whale
Humpback whale
Gray whale
*Minke whale
PROTECTING AND SUSTAINING PROTECTING AND SUSTAINING MARINE BIODIVERSITYMARINE BIODIVERSITY
Fully Fully protected marine reservesprotected marine reserves make up less than make up less than 0.3% of the world’s ocean area.0.3% of the world’s ocean area.
Marine Reserves Work:Marine Reserves Work: Studies show that in protected areas:Studies show that in protected areas:
• fish populations doublefish populations double• fish size grows by almost a thirdfish size grows by almost a third• reproduction triples reproduction triples • 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 plansintegrated plans for managing their coastal areas. for managing their coastal areas.
Revamping Ocean PolicyRevamping Ocean Policy
Two recent studies called for an Two recent studies called for an overhaul of overhaul of U.S. ocean policy and managementU.S. ocean policy and management.. Create a Create a National Oceans AgencyNational Oceans Agency within the within the
Executive Office of the PresidentExecutive Office of the President Develop Develop unified national policyunified national policy.. Double federal budgetDouble federal budget for ocean research. for ocean research. Set up Set up network of marine reservesnetwork of marine reserves.. Reorient fisheries management towards Reorient fisheries management towards
ecosystem functionecosystem function.. Increase public awarenessIncrease public awareness..
MANAGING AND SUSTAINING MANAGING AND SUSTAINING MARINE FISHERIESMARINE FISHERIES
There are a number of ways to There are a number of ways to manage manage marine fisheriesmarine fisheries more sustainably and protect more sustainably and protect marine biodiversity.marine biodiversity.
Some fishing communities regulate fish Some fishing communities regulate fish harvests on their own and others work with harvests on their own and others work with the government to regulate them.the government to regulate them. Modern fisheries have weakenedModern fisheries have weakened the ability of the ability of
many coastal communities to regulate their own many coastal communities to regulate their own fisheries.fisheries.
Fig. 12-7, p. 261
SolutionsManaging Fisheries
FISHERY REGULATIONS
Set catch limits well below the maximum sustainable yield
Improve monitoring and enforcement of regulations
ECONOMIC APPROACHES
Sharply reduce or eliminate fishing subsidies
Charge fees for harvesting fish and shellfish from publicly owned offshore waters
Certify sustainable fisheries
PROTECTED 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, sea turtles, and bycatch fish
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
NON-NATIVE 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
PROTECTING, SUSTAINING, AND PROTECTING, SUSTAINING, AND RESTORING WETLANDSRESTORING WETLANDS
The US has lost The US has lost more than 50%more than 50% of our original wetlands of our original wetlands
Figure 12-8Figure 12-8
PROTECTING, SUSTAINING, AND PROTECTING, SUSTAINING, AND RESTORING WETLANDSRESTORING WETLANDS
Mitigation bankingMitigation banking allows wetlands to be developed allows wetlands to be developed as long as an equal area of wetland is created or as long as an equal area of wetland is created or restoredrestored At least 50% of wetland mitigation projects failAt least 50% of wetland mitigation projects fail Mitigation has worked in Coastal Georgia salt marshesMitigation has worked in Coastal Georgia salt marshes
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
Case Study: Case Study: Restoring the Florida EvergladesRestoring the Florida Everglades
The The world’s largestworld’s largest ecological restoration ecological restoration projectproject involves trying to undo some of the involves trying to undo some of the damage inflicted on the Everglades by damage inflicted on the Everglades by human activities.human activities. Large volumes of waterLarge volumes of water that once flowed through that once flowed through
the park have been the park have been diverted for crops and citiesdiverted for crops and cities.. 90% of park’s 90% of park’s wading birdswading birds have vanished. have vanished. Other vertebrate populationsOther vertebrate populations down 75-95%. down 75-95%. Runoff has caused Runoff has caused noxious algal bloomsnoxious algal blooms in in
nearby coastal waters.nearby coastal waters.
Restoring the Restoring the Florida Florida
EvergladesEverglades
The the The the US Army US Army Corps of EngineersCorps of Engineers has been has been attempting to attempting to restore the 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 Lakes are difficult to managedifficult to manage and are and are vulnerable to planned or unplanned vulnerable to planned or unplanned introductions of nonnative species.introductions of nonnative species.
For decades, For decades, invasions by nonnative speciesinvasions 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.
Columbia Columbia River:River:
FormerFormer(Future?)(Future?)Salmon Salmon Habitat Habitat
PROTECTING, SUSTAINING, AND PROTECTING, SUSTAINING, AND RESTORING LAKES AND RIVERSRESTORING LAKES AND RIVERS
Sept-Dec
In stream gravel Jan-April
Emerge May-June
A few months to 2 years
Migrate to ocean in April- Aug
Mature in ocean 2-5 yrs
Migrate to “natal stream”
Spawn Sept-Nov
PROTECTING, SUSTAINING, AND PROTECTING, SUSTAINING, AND RESTORING LAKES AND RIVERSRESTORING LAKES AND RIVERS
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
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 River119 dams on Columbia River have sharply have sharply
reduced (94% drop) populations of reduced (94% drop) populations of wild salmonwild salmon.. U.S. government has spent $3 billion in U.S. government has spent $3 billion in
unsuccessful effortsunsuccessful efforts to save the salmon. to save the salmon. Removing hydroelectric damsRemoving hydroelectric dams will restore native will restore native
spawning grounds (economic implications?)spawning grounds (economic implications?)
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 protectingbuilding and protecting populations of populations of desirable species, desirable species, preventing over-fishingpreventing over-fishing, , and and decreasing populationsdecreasing populations of less desirable 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).
National Wild and Scenic Rivers ActNational Wild and Scenic Rivers Act 2% of US rivers remain 2% of US rivers remain
free flowingfree flowing 0.2% of US rivers are 0.2% of US rivers are
protected by the Wild protected by the Wild and Scenic Rivers Actand Scenic Rivers Act
Smith River, CA
Vermillion River, IL
National Wild and Scenic Rivers ActNational Wild and Scenic Rivers Act
Skagit River, North Cascade Mountains, WA
National Wild and Scenic Rivers ActNational Wild and Scenic Rivers Act Wild Rivers-Wild Rivers- untamed and untamed and inaccessible except inaccessible except
by trailby trail; no widening, straightening, dredging, ; no widening, straightening, dredging, filling, or damming; filling, or damming; no motor boats allowedno motor boats allowed
Scenic Rivers-Scenic Rivers- of great scenic value and of great scenic value and accessible by a few roadsaccessible by a few roads; free of dams, mostly ; free of dams, mostly undeveloped; undeveloped; no motor boats allowedno motor boats allowed
Recreational Rivers-Recreational Rivers- easily accessibleeasily accessible; may ; may have some dams or shore development; have some dams or shore development; motor motor boats allowed.boats allowed.
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