Sustaining Aquatic Biodiversity FMS 2013 APES Chapter 13.

Sustaining Aquatic Biodiversity

FMS 2013APES

Chapter 13

Key Concepts

Economic and ecological importance

Effects of human activities

Protecting and sustaining aquatic diversity

Protecting and sustaining fisheries

Protecting and restoring wetlands

Case Study: A Biological Roller Coaster Ride in Lake Victoria

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

Case Study: A Biological Roller Coaster Ride in Lake Victoria

1980s – 500 species of fish

80% were cichlids (algae eating fish with slightly different niches)

50% of Cichlid species have gone extinct since

A Biological Roller Coaster Ride in Lake Victoria

• Reasons for Lake Victoria’s loss of biodiversity:– Introduction of Nile perch.– Loss of native cichlid species– 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.

AQUATIC BIODIVERSITY

• We know fairly little about the biodiversity of the world’s marine and freshwater systems.

• The world’s marine and freshwater systems provide important ecological and economic services.

The Importance of Aquatic Biodiversity

• The most biologically The most biologically diverse habitats diverse habitats include:include:– Coral reefsCoral reefs– EstuariesEstuaries– Deep ocean floorDeep ocean floor

– Huge diversity of Huge diversity of habitats and food habitats and food sourcessources

– Highest near the coast Highest near the coast ( variety habitats ( variety habitats and producers )and producers )

– 25,000 fish species25,000 fish species

The Importance of Aquatic Biodiversity:Ecological and Economic

• Food ItemsFood Items– 6% of total protein; 6% of total protein;

16% of animal protein16% of animal protein

• Many ChemicalsMany Chemicals– CosmeticsCosmetics

• from seaweedfrom seaweed– Medicines and DrugsMedicines and Drugs

• Antibiotics and Antibiotics and anticancer drug, anticancer drug, adhesives, bone adhesives, bone reconstructive reconstructive materialsmaterials

• seaweed, sponges, seaweed, sponges, mollusks, coral mollusks, coral barnacles, and other barnacles, and other fishfish

Human Impacts on Aquatic Biodiversity

• Species loss and endangermentSpecies loss and endangerment• Marine habitat loss and degradationMarine habitat loss and degradation• Freshwater habitat loss and Freshwater habitat loss and

degradationdegradation• OverfishingOverfishing• Nonnative speciesNonnative species• Pollution and climate changePollution and climate change

Species Loss and Endangerment

• Overfishing• Habitat destruction• Pollution• Freshwater species at greater risk

– Mussels, crayfish, amphibians, fish

Marine Habitat Loss and Degradation

• 53% of coastal wetlands in US have 53% of coastal wetlands in US have disappeareddisappeared– AgricultureAgriculture– Coastal developmentCoastal development

• 58% of world’s coral reefs are 58% of world’s coral reefs are threatenedthreatened– Coastal developmentCoastal development– PollutionPollution– Warmer ocean temperaturesWarmer ocean temperatures

• Two-thirds of US estuaries are at risk Two-thirds of US estuaries are at risk from pollutionfrom pollution

• 35% of world’s mangroves have 35% of world’s mangroves have disappeareddisappeared

Freshwater Habitat Loss and Degradation

• The world has lost more than half of its inland wetlands– Agricultural and urban development

• 60% of the world’s larger rivers are fragmented by dams, diversions, and canals

• Flood control levees and dikes– Alter and destroy aquatic habitats– Disconnect rivers from their floodplains– Eliminate wetlands and backwaters

(spawning areas)

Overfishing

• 75% of the world’s 200 75% of the world’s 200 commercially valuable marine fish commercially valuable marine fish species are overfishedspecies are overfished

• Overfishing leads to Overfishing leads to commercial commercial extinctionextinction

• Depletions and extinction of Depletions and extinction of species unintentionally caught as species unintentionally caught as bycatchbycatch

Non-native Species

• Deliberate or accidental introduction Deliberate or accidental introduction into coastal waters, lakes and wetlandsinto coastal waters, lakes and wetlands– purple loosestrifepurple loosestrife– Asian swamp eelAsian swamp eel– zebra musslezebra mussle

• Displace or cause extinction of native Displace or cause extinction of native speciesspecies– 68% of fish extinctions68% of fish extinctions

Pollution and Climate Change

• Major pollution threatsMajor pollution threats– OilOil– Acid depositionAcid deposition– Plant nutrientsPlant nutrients– Toxic chemicalsToxic chemicals– Coastal Coastal

developmentdevelopment– Sediment and soil Sediment and soil

erosionerosion

Climate Change couldClimate Change could

alter migration and alter migration and feeding patternsfeeding patterns

increase ocean increase ocean temperaturetemperature

raise sea levelsraise sea levels

• 44% comes from runoff from developed 44% comes from runoff from developed coastal areascoastal areas

PROTECTING AND SUSTAINING MARINE BIODIVERSITY

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

Figure 12-4Figure 12-4

Protect endangered and Protect endangered and threatened speciesthreatened species

• Example: Sea turtleExample: Sea turtle– Turtle extrusion devices (TEDs)Turtle extrusion devices (TEDs)

Loggerhead

Olive ridley

Leatherback

Hawksbill

Green turtleKemp's Ridley

Black turtle

Australian flatback

Shrimp trawler

Area enlarged right

Turtle Extrusion Device

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

Human Demand for Seafood is Outgrowing the Sustainable Yield

for most Fisheries

Commercial Extinction

When it is no longer profitable to continue fishing the affected species.

Domino Effect of Losing CodFishermen turned to fishing sharks

Shark populations in the N. Atlantic declined by 99%

Sharks are important apex predators that hunt rays and skates.

Subsequently – ray and skate populations exploded, which caused a decline in Bay Scallops

Class Activity4 groups: Trawlers, Purse Seine, Long Line, Drift Net

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.

Sucks to be a whale

Whales are easy to kill because of their large size and that they need to come to the surface to breath.

Overharvesting has driven the Blue Whale close to biological extinction

Blue Whales Continued….

What is Being Done?• 1946 – the IWC

(International Whaling Commission) set out to regulate whaling• Set quotas to prevent

overharvesting and commercial extinction.

• Problem: No power of enforcement = ignored!

Case Study:Holding Out Hope for Marine Turtles

Of the 7 species of marine turtles, 6 are either critically endangered or endangered.

Example: Leatherback

Case Study:Holding Out Hope for Marine Turtles

Leatherback Problems

Survived for roughly 100 million years, but faces possible extinction

Stable in Atlantic, but declined by 95% in PacificBottom trawlers are destroying the coral gardens that

serve as their feeding groundsThey are hunted for meat, leather, and eggsThey drown in nets, on lines, and in trapsThey choke on plasticArtificial lights disorient hatchlings and end up predatedSea levels flooding nesting habitats and disrupt migration

patterns

Case Study:Holding Out Hope for Marine Turtles

How are we protecting them?

Turning off lights during hatching seasonNesting areas roped off

Since 1991, US gov’t requires offshore shrimp trawlers to use turtle excluder devices (TEDs) that help keep sea turtles from being caught in nets or allow them to escape.

In 2004, US gov’t banned long-lining for swordfish off Pacific coast to help save dwindling sea turtle populations there.

Case Study:Holding Out Hope for Marine TurtlesHow are we protecting them?

Playa Junquillal, NW coast of Costa Rica, use ecotourism instead of selling turtle products.

In 2004, volunteers and the WWF biologists, went out to find and rescue turtle nests in Costa Rica before they could be poached, and built hatcheries to protect the eggs. Prior, all nests were poached, a year later, none were poached.

Marine sanctuaries protect ecosystems and speciesBy international law, a country’s offshore

fishing zone extends this far from its shores:370 km (200 nautical miles)

Foreign fishing vessels can take certain quotas of fish within such zones with the government’s permission called:Exclusive economic zones

Ocean areas beyond such zones have laws and treaties pertaining to them, but they are hard to monitor and enforce. These areas are called:The high seas

Marine sanctuaries protect ecosystems and speciesSince 1986, the IUCN has helped to establish

a global system of marine protected areas (MPAs)- areas of ocean partially protected from human activities. There are more than 4,000 MPAs worldwide.

“Partially Protected” they still allow:DredgingTrawler fishingOther ecologically harmful resource extraction

activities

Marine sanctuaries protect ecosystems and speciesHowever, In 2007, California began

establishing the nation’s most extensive network of MPAs in which fishing will be banned or strictly limited.

Establishing a global network of marine reserves: an ecosystem approach to marine sustainabilityThe primary objective of this ecosystem approach is to protect and sustain the whole marine ecosystem for current and future generations instead of focusing primarily on protecting individual species.

Establishing a global network of marine reserves: an ecosystem approach to marine sustainabilityMarine reserves are fully protected and off-

limits to human activities to enable these areas to recover.

A global network would include large reserves on the high seas (near upwelling sites), and a mixture of smaller reserves in coastal zones (near commercial fishing areas).

Sites can be temporary or moveable (migrating species).

Establishing a global network of marine reserves: an ecosystem approach to marine sustainabilityStudies show that within fully protected

marine reserves, commercially valuable fish populations double, fish size grows by almost a third, fish reproduction triples, and species diversity increases by 25%.

These positive changes could happen within 2-4 years and last for decades.

Establishing a global network of marine reserves: an ecosystem approach to marine sustainabilityReserves also help nearby fisheries because

fish move in and out of reserve and larvae float on currents to fishing grounds.

Establishing a global network of marine reserves: an ecosystem approach to marine sustainabilityIn 2009, a group of Pacific island nations put

4 areas of international waters off limits to fishing to save world’s last great tuna stocks.

In 2008, Kiribati established a reserve the size of California between Fiji and Hawaii.

In 2006, the US created a large reserve NW of the Hawaiian Islands.

Establishing a global network of marine reserves: an ecosystem approach to marine sustainabilityDespite all of this, less than 1% of the world’s

oceans are in marine reserves and only 0.1% fully protected.

Many marine scientists call for 30 – 50% protection with protected corridors between them.

In 2004, a study by a team of U.K. scientists showed it would cost the same as the subsidies that promote overfishing.

Some Marine Systems Can Be RestoredThe example of reef restoration by a

restaurant owner in Israel is an application of:Reconciliation ecology

Another example is Japan attempting to restore its largest coral reef- 90% died- by seeding it with new corals.

Other ecosystems that could be restored:Mangrove forestsCoastal marshesSea-grass beds

Protecting marine biodiversity requires commitments from individuals and communitiesWhat can individuals and communities do?

Monitor and regulate fishing and coastal land development

Greatly reduce pollution from land-based activitiesThink about what you put on your lawns and the

kinds of waste generatedChoose sustainably harvested and farmed seafoodReduce carbon footprint

Protecting marine biodiversity requires commitments from individuals and communitiesOne emerging strategy is a community based

effort to develop and use coastal resources more sustainably and it is called:Integrated coastal managementAustralia manages its Great Barrier Reef

Marine Park in this way.US example: Chesapeake Bay Program

Protecting marine biodiversity requires commitments from individuals and communitiesThe overall aim of these programs is for

fishers, business owners, developers, scientists, citizens, and politicians to identify shared problems and goals in their use of marine resources.

This requires short-term trade-offs!

Key Concepts

Economic and ecological importance

Effects of human activities

Protecting and sustaining aquatic diversity

Protecting and sustaining fisheries

Protecting and restoring wetlands

Estimating and monitoring fishery populations is the first stepThere are many methods of estimating populations of fish and

shellfish:Maximum sustained yield (MSY) model

Maximum # of fish that can be harvested from a fish stock without causing the population to decline.

Optimum sustained yield (OSY) concept Takes into account interactions between species

Multispecies Management approach Takes into account predation and competition

Computer models for managing multispecies fisheries in large marine systems

There are uncertainties built into using any of these approaches, so environmental scientists suggest using the precautionary principle, closing some over-fished areas until they recover and we have more information.

Some communities cooperate to regulate fish harvestsMany fishing communities have developed

allotment and enforcement systems for controlling fish catches in which each fisher gets a share of the total allowable catch. These are called:

Catch-share systems

Some communities cooperate to regulate fish harvestsWith influx of large modern fishing boats,

community management systems have been replaced by co-management systems (communities and gov’t work together).

Here, gov’t sets quotas for species and divides among communities. May limit fishing season or type of gear used. Usually community manages inshore fisheries and the gov’t manages offshore.

Government subsidies can encourage overfishingA 2006 study estimates the gov’t around the

world give a total of about $30 – 34 billion per year in subsidies to fishers to keep businesses running.

Of that, $20 billion helps them buy ships, fuel, and fishing equipment, the remaining to research and management of fisheries.

Some argue that it encourages overfishing, resulting in too many boats chasing too little fish.

Some countries are using individual transfer rights (ITRs), or fish shares, you get a quota and can sell/lease your shares.

Consumer choices can help sustain fisheries and aquatic biodivesityAn important component of sustaining aquatic

biodiversity and ecosystem services is bottom-up pressure from consumers demanding:Sustainable seafood

Know how and where caughtIs it certified by the Marine Stewardship

Council and have the eco-label “Fish Forever”?Does it have a certified label of sustainable

aquaculture or fish farming?

Coastal and inland wetlands are disappearing around the worldU.S. has lost more than half of its coastal and

inland wetlands since 1900.New Zealand has lost 92% of its original

coastal wetlandsItaly has lost 95%

Coastal and inland wetlands are disappearing around the worldDrained, filled in, or covered over to create

fields, cities, suburbs, and roadsDestroyed to extract minerals, oils, and

natural gas, and to eliminate breeding grounds for insects that cause disease.

Rising sea levels

Coastal and inland wetlands are disappearing around the worldAs of 2006 New Jersey is the 11th most populated

state in the nation, but the most densely populated, with 1,174 residents per square mile.

Since the 1780's, the state has lost approximately 39% of it's wetlands, from an estimated 1,500,000 acres down to 915,960 acres of wetlands in the 1980's.

Wetlands in New Jersey face significant pressures, including development and pollution; more than half of the 109 Superfund sites in New Jersey are adjacent to wetlands.

Despite a strong state program, wetlands are still being lost in New Jersey, at a rate of approximately 138 acres a year between 1988 and 2001, according to the NJ DEP.

We can preserve and restore wetlandsZoning laws:

US requires a permit to fill in wetlands occupying more than 1.2 hectares (3 acres) or to deposit dredged material on them. Helped cut annual wetland loss by 80% since 1969

Mitigation Banking is a policy that allows destruction of existing wetlands as long as an equal area of the same type is created or restored.

Difficult to do

Most restored wetlands fail or do not perform their ecological functions – However, Army Corp. of Engineers and private investors make huge profits failing!

Must be created or restored before existing wetlands destroyed

Case Study: Can We Restore the Florida Everglades?Between 1962 and 1971, US Army Corps of

Engineers straightened and built a canal on Kissimmee River

Work done to the river dried out much of the Everglades and then converted to farmland

Population increased; more developmentMuch of Everglades drained, diverted, paved

over, polluted by agricultural runoff, and invaded by many species.

Case Study: Can We Restore the Florida Everglades?Outcomes:

Everglades half the sizeVulnerable to summer wildfires90% of wading birds gonePopulations of vertebrates from deer to turtles down

75-95%Florida Bay now saltier and warmer due to diversion

of fresh water for crops and citiesAlgal blooms, sometimes covering 40% of the bay,

due to nutrient output from farms and citiesBay and Florida Keys coral reefs, diving, fishing, and

tourism affected

Case Study: Can We Restore the Florida Everglades?In 1990, Florida’s state gov’t and the US

gov’t agreed on the world’s largest ecological restoration project known as the Comprehensive Everglades Restoration Plan (CERP).

Case Study: Can We Restore the Florida Everglades?Goals of the plan:

Restore curving flow of Kissimmee RiverRemove 250 miles of canals and levees

blocking water south of Lake OkeechobeeBuy 93 sq mi of farmland and allow it to be

floodedCreate 18 large reservoirs and underground

storageBuild new canals, reservoirs, and pumping

systems to catch water flowing out to sea and return it to Everglades

Case Study: Can We Restore the Florida Everglades?Plan is beginning to unravel

2003, sugarcane growers convinced FL gov’t to increase amount of phosphorus and to extend deadline for reducing from 2006 to 2016

Experienced cost overruns Funding, esp. fed. Gov’t has fallen short

Far behind on almost every component of the project

Case Study: Can We Restore the Florida Everglades?Bottom Line:

Prevention of environmental harm works better and is less costly then trying to undo it

When we intervene in nature, unitended and often harmful consequences usually result.

Classic case of where the precautionary principle should have been used!

Freshwater ecosystems are under major threatsUse HIPPCO

40% of the world’s rivers have been dammed or otherwise engineered

Many of the world’s wetlands have been destroyed

Aquatic species have been crowded out of at least ½ of the world’s freshwater habitat areas

Invasive species, pollution, climate change threaten many ecosystems

Increasing human population and projected climate change make these matters worse

Case Study: Can the Great Lakes Survive Repeated Invasions by Alien Species?The Great Lakes are the world’s largest body

of fresh water.Since the 1920s, they have been invaded by at

least 162 nonnative speciesOne of the biggest threats is the sea lamprey, a

parasite of almost any fish, depleting many species, like trout

US and Canada use chemicals to kill sea lamprey larvae that costs $15 million per year

Case Study: Can the Great Lakes Survive Repeated Invasions by Alien Species?Another invader: the zebra mussel from Europe from

ballast water!Has no known enemies in the Great LakesDisplaced many mussel species and thus depleted food

supply for other speciesClogged irrigation pipes, shut down water intake pipes,

fouled beaches, jammed ships’ rudders, grown in huge masses on boat hulls, piers, pipes, rocks…everywhere!

Costs US and Canada $1 billion/year or $114,000 per hour

Case Study: Can the Great Lakes Survive Repeated Invasions by Alien Species?Another mussel: guagga mussel from RussiaCan survive greater depths and tolerate more

extremes than zebra musselsHave rapidly replaced many other bottom-

dwellers in Lake Michigan, reducing food supply

It is now found all the way in the Colorado River and its reservoir system

Case Study: Can the Great Lakes Survive Repeated Invasions by Alien Species?The Asian or grass carp brought up by catfish

farmers from the south to help remove suspended matter and algae from their aquaculture farm ponds

Flooding released them into the Mississippi RiverHave moved north to the Illinois River and some

found in Lake MichiganProlific swimmers, voracious appetite, can

jump/collide, have no natural predators

Managing river basins is complex and controversialRivers and streams’ ecological and economic

services disrupted by:OverfishingPollutionDamsWater withdrawl for irrigation

Managing river basins is complex and controversialColumbia River (runs through SW Canada and NW

US) an example of this disruptionHas 119 dams (19 as hydroelectric power) and

supplies water to major urban areas and large irrigation projects

Reduced populations of wild salmon by interfering with mature fish returning to spawn

Drop in population by 94% since dams were built9 species of salmon listed as endangered or

threatenedGov’t has spent $3 billion to save them to no avail

Managing river basins is complex and controversialSnake River (State of Washington) another

example of this disruptionConservationists, native American tribes, and

commercial salmon fishers want the gov’t to remove four small hydroelectric dams to restore salmon spawning habitat

Farmers, barge operators, and aluminum workers argue that removing the dams would hurt local economies by reducing irrigation water, eliminate shipping, and reducing supply of cheap electricity

We can protect freshwater ecosystems by protecting watershedsLakes and streams receive many of their

nutrients from ecosystems of bordering land such as: from falling leaves, animal feces, and pollutants generated by people.

All these inputs are washed into bodies of water by rainstorms and melting snow.

Therefore, to protect rivers and streams, we must protect its watershed from excessive inputs.

We can protect freshwater ecosystems by protecting watershedsIn 1968, National Wild and Scenic Rivers ActWild rivers: those relatively inaccessibleScenic rivers: those of great scenic value that

are free of dams, mostly undeveloped, and only accessible in a few places

These rivers are protected from widening, straightening, dredging, filling, and damming

Only keeps 3% rivers free-flowing and 1% protected

Freshwater fisheries need better protectionSustainable management involves

Supporting populations of commercial and sport fish species

Preventing such species from being overfishedReducing or eliminating invasive species

Traditionally done by:Regulate time and length of fishing seaonsRegulate the number and size of fish that can

be taken

Freshwater fisheries need better protectionOther techniques:

Building, stocking, and protecting reservoirs and ponds with fish

Preventing sediment buildup and pollutionControlling predators, parasites, and diseases

by improving habitats, breeding genetically resistant fish varieties, using antibiotics and disinfectants

Hatcheries can also be used to restock bodies of water with fish