chapter 6 miller

8/14/2019 Chapter 6 Miller

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Chapter 6Chapter 6

Aquatic BiodiversityAquatic Biodiversity



Chapter Overview QuestionsChapter Overview Questions

What are the basic types of aquatic life zonesWhat are the basic types of aquatic life zonesand what factors influence the kinds of lifeand what factors influence the kinds of lifethey contain?they contain?

What are the major types of saltwater lifeWhat are the major types of saltwater lifezones, and how do human activities affectzones, and how do human activities affectthem?them?

What are the major types of freshwater lifeWhat are the major types of freshwater lifezones, and how do human activities affectzones, and how do human activities affectthem?them?



Updates OnlineUpdates Online

The latest references for topics covered in this section can be found atThe latest references for topics covered in this section can be found atthe book companion website. Log in to the book’s e-resources page atthe book companion website. Log in to the book’s e-resources page atwww.thomsonedu.com to access InfoTrac articles.www.thomsonedu.com to access InfoTrac articles.

InfoTrac: Down the bayou: a marine biologist, a community,InfoTrac: Down the bayou: a marine biologist, a community,and the resolve to preserve an ocean's bounty. Taylor Sisk.and the resolve to preserve an ocean's bounty. Taylor Sisk.Earth Island Journal Earth Island Journal , Autumn 2006 v21 i3 p27(6)., Autumn 2006 v21 i3 p27(6).

InfoTrac: A scourge of the '70s returns to Great Lakes.InfoTrac: A scourge of the '70s returns to Great Lakes. TheThe

Christian Science Monitor Christian Science Monitor , March 30, 2006 p14., March 30, 2006 p14.

InfoTrac: The fate of the ocean. Julia Whitty.InfoTrac: The fate of the ocean. Julia Whitty. Mother Jones,Mother Jones, March-April 2006 v31 i2 p32(15).March-April 2006 v31 i2 p32(15).

National Oceanic and Atmospheric Administration: FisheriesNational Oceanic and Atmospheric Administration: Fisheries

Amazon Conservation Association: Amazon Rivers ProjectAmazon Conservation Association: Amazon Rivers Project



Core Case Study:Core Case Study:

Why Should We Care About CoralWhy Should We Care About Coral

Reefs?Reefs?

Coral reefs form inCoral reefs form in

clear, warmclear, warmcoastal waters of coastal waters of the tropics andthe tropics and

subtropics.subtropics. Formed byFormed by

massive coloniesmassive coloniesof polyps.of polyps.

Figure 6-1Figure 6-1



Fig. 6-1a, p. 126



Fig. 6-1b, p. 126



Core Case Study:Core Case Study:

Why Should We Care About CoralWhy Should We Care About Coral

Reefs?Reefs?

Help moderate atmospheric temperature byHelp moderate atmospheric temperature by

removing COremoving CO22 from the atmosphere.from the atmosphere. Act as natural barriers that help protect 14% of Act as natural barriers that help protect 14% of

the world’s coastlines from erosion bythe world’s coastlines from erosion by

battering waves and storms.battering waves and storms. Provide habitats for a variety of marineProvide habitats for a variety of marine

organisms.organisms.



AQUATIC ENVIRONMENTSAQUATIC ENVIRONMENTS

Saltwater and freshwater aquatic life zonesSaltwater and freshwater aquatic life zonescover almost three-fourths of the earth’scover almost three-fourths of the earth’ssurfacesurface



http://slidepdf.com/reader/full/chapter-6-miller 9/55Fig. 6-2, p. 127

Land–ocean hemisphereOcean hemisphere



AQUATIC ENVIRONMENTSAQUATIC ENVIRONMENTS




What Kinds of Organisms Live inWhat Kinds of Organisms Live in

Aquatic Life Zones?Aquatic Life Zones? Aquatic systems contain floating, drifting,Aquatic systems contain floating, drifting,

swimming, bottom-dwelling, and decomposer swimming, bottom-dwelling, and decomposer organisms.organisms. Plankton: important group of weakly swimming,Plankton: important group of weakly swimming,

free-floating biota.free-floating biota.• Phytoplankton (plant), Zooplankton (animal),Phytoplankton (plant), Zooplankton (animal),

Ultraplankton (photosynthetic bacteria)Ultraplankton (photosynthetic bacteria)

Necton: fish, turtles, whales.Necton: fish, turtles, whales. Benthos: bottom dwellers (barnacles, oysters).Benthos: bottom dwellers (barnacles, oysters). Decomposers: breakdown organic compoundsDecomposers: breakdown organic compounds

(mostly bacteria).(mostly bacteria).



Life in LayersLife in Layers

Life in most aquatic systems is found inLife in most aquatic systems is found insurface, middle, and bottom layers.surface, middle, and bottom layers.

Temperature, access to sunlight for Temperature, access to sunlight for

photosynthesis, dissolved oxygen content,photosynthesis, dissolved oxygen content,nutrient availability changes with depth.nutrient availability changes with depth. Euphotic zone (upper layer in deep water Euphotic zone (upper layer in deep water

habitats): sunlight can penetrate.habitats): sunlight can penetrate.



SALTWATER LIFE ZONESSALTWATER LIFE ZONES

The oceans thatThe oceans thatoccupy most of theoccupy most of theearth’s surfaceearth’s surface

provide manyprovide manyecological andecological andeconomic services.economic services.




Natural Capital

Climate moderation Food

Animal and petfeed

Pharmaceuticals

Harbors andtransportation routes

Coastal habitats for humans

Recreation

Employment

Oil and natural gas

Minerals

Building materials

CO2 absorption

Nutrient cycling

Scientific

information

Marine Ecosystems

Ecological

Services

Economic

Services

Geneticresources andbiodiversity

Habitats and

nursery areas

Reduced stormimpact (mangroves,barrier islands,coastal wetlands)

Waste treatment



The Coastal Zone:The Coastal Zone:

Where Most of the Action IsWhere Most of the Action Is The coastal zone: the warm, nutrient-rich,The coastal zone: the warm, nutrient-rich,

shallow water that extends from the high-tideshallow water that extends from the high-tidemark on land to the gently sloping, shallowmark on land to the gently sloping, shallow

edge of the continental shelf.edge of the continental shelf. The coastal zone makes up less than 10% of The coastal zone makes up less than 10% of

the world’s ocean area but contains 90% of allthe world’s ocean area but contains 90% of allmarine species.marine species. Provides numerous ecological and economicProvides numerous ecological and economic

services.services. Subject to human disturbance.Subject to human disturbance.



The Coastal ZoneThe Coastal Zone


Hi h tid



D a r

k n

e s

s

T w i l i g h t

P h

o t o

s y

n t h

e s

i s

Sun

Continentalshelf

EstuarineZone

High tide

Low tide

CoastalZone

Bathyal Zone

Euphotic Zone

Abyssal

Zone

Sea level

OpenSea



Marine EcosystemsMarine Ecosystems

Scientists estimateScientists estimatethat marine systemsthat marine systemsprovide $21 trillion inprovide $21 trillion in

goods and servicesgoods and servicesper year – 70% moreper year – 70% morethan terrestrialthan terrestrial

ecosystems.ecosystems.




Estuaries and Coastal Wetlands:Estuaries and Coastal Wetlands:

Centers of ProductivityCenters of Productivity Estuaries include river Estuaries include river

mouths, inlets, bays,mouths, inlets, bays,

sounds, salt marshessounds, salt marshesin temperate zonesin temperate zones

and mangrove forestsand mangrove forests

in tropical zones.in tropical zones.


Herring gulls


http://slidepdf.com/reader/full/chapter-6-miller 21/55Fig. 6-7a, p. 131

All consumers

and producersto decomposers

Secondary to

higher-levelconsumer

Primary to

secondaryconsumer

Producer to

primaryconsumer

Soft-shelledclam

Bacteria

Clamworm

Zooplankton andsmall crustaceans

Smelt

MarshPeriwinkle

Phytoplankton

Herring gulls

Snowy

Egret

Peregrine falcon

Cordgrass

Short-billedDowitcher


http://slidepdf.com/reader/full/chapter-6-miller 22/55Fig. 6-7b, p. 131



Mangrove Forests (Stopped)Mangrove Forests (Stopped)

Are found alongAre found alongabout 70% of about 70% of gently slopinggently sloping

sandy and siltysandy and siltycoastlines incoastlines intropical andtropical and

subtropicalsubtropicalregions.regions.




Estuaries and Coastal Wetlands:Estuaries and Coastal Wetlands:

Centers of ProductivityCenters of Productivity Estuaries and coastal marshes provideEstuaries and coastal marshes provide

ecological and economic services.ecological and economic services. Filter toxic pollutants, excess plant nutrients,Filter toxic pollutants, excess plant nutrients,

sediments, and other pollutants.sediments, and other pollutants. Reduce storm damage by absorbing wavesReduce storm damage by absorbing waves

and storing excess water produced by stormsand storing excess water produced by stormsand tsunamis.and tsunamis.

Provide food, habitats and nursery sites for Provide food, habitats and nursery sites for many aquatic species.many aquatic species.



Rocky and Sandy Shores:Rocky and Sandy Shores:

Living with the TidesLiving with the Tides

Organisms experiencing daily low and highOrganisms experiencing daily low and high

tides have evolved a number of ways totides have evolved a number of ways to

survive under harsh and changing conditions.survive under harsh and changing conditions. Gravitational pull by moon and sun causes tides.Gravitational pull by moon and sun causes tides. Intertidal Zone: area of shoreline between lowIntertidal Zone: area of shoreline between low

and high tides.and high tides.



Rocky and Sandy Shores:Rocky and Sandy Shores:

Living with the TidesLiving with the Tides

Organisms inOrganisms in

intertidal zoneintertidal zone

develop specializeddevelop specializedniches to deal withniches to deal with

daily changes in:daily changes in:

TemperatureTemperature SalinitySalinity Wave actionWave action




Fig. 6-9, p. 132

Rocky Shore Beach

Sea star Hermit crab Shore crab

AnemoneSea urchin

Sculpin

Nudibranch

Low tide

Monterey flatworm

Kelp Sea lettuce

Barnacles

Mussel

Periwinkle

High tide



Fig. 6-9, p. 132

Barrier Beach

Peanut worm

Beach flea

Tiger Beetle

Dwarf Olive

Clam

High tide

GhostShrimpMole

Shrimp

Sandpiper

Moon

snail

Sand dollar White sand

macoma

Blue crab

Low tideSilversides



Barrier IslandsBarrier Islands

Low, narrow, sandy islands that form offshoreLow, narrow, sandy islands that form offshore

from a coastline.from a coastline. Primary and secondary dunes on gentlyPrimary and secondary dunes on gently

sloping sandy barrier beaches protect landsloping sandy barrier beaches protect land

from erosion by the sea.from erosion by the sea. Figure 6-10Figure 6-10



Fig. 6-10, p. 133

Ocean Beach

Primary

Dune

Secondary

DuneTrough Back Dune

Bay or

LagoonLimited

recreationand walkways

Intensiverecreation,no building

Intensiverecreation

Most suitablefor development

Taller shrubs and treesTaller shrubs

Grasses or

shrubs

No directpassage

or building

No directpassage

or building

No filling

Bay shore



Threats toThreats to

Coral Reefs:Coral Reefs:

IncreasingIncreasingStressesStresses

BiologicallyBiologicallydiverse anddiverse andproductive coralproductive coralreefs are beingreefs are being

stressed bystressed byhuman activities.human activities.


Gray reef shark



Fig. 6-11, p. 134

All consumer

and producersto decomposers

Secondary to

higher-levelconsumer

Primary to

secondaryconsumer

Producer to

primaryconsumer

Green sea

turtle

Sea nettle

Blue

tangs

Fairy basslet

Sergeant major

Brittle star Banded coralshrimp

Algae

Phytoplankton

Coney

Morayeel

Blackcap basslet

Bacteria

Zooplankton

Sponges

Symbiotic

algae

Hard corals

Parrot fish

y

Natural Capital Degradation



Fig. 6-12, p. 135

Ocean warming

Soil erosion

Algae growth from fertilizer runoff

Mangrove destruction

Bleaching

Rising sea levels

Increased UV exposure

Damage from anchors

Damage from fishing and diving


Coral Reefs



Biological Zones in the Open Sea:Biological Zones in the Open Sea:

Light RulesLight Rules

Euphotic zoneEuphotic zone: brightly lit surface layer.: brightly lit surface layer. Nutrient levels low, dissolved ONutrient levels low, dissolved O

22high,high,

photosynthetic activity.photosynthetic activity. Bathyal zoneBathyal zone: dimly lit middle layer.: dimly lit middle layer.

No photosynthetic activity, zooplankton and fishNo photosynthetic activity, zooplankton and fish

live there and migrate to euphotic zone to feed atlive there and migrate to euphotic zone to feed atnight.night.

Abyssal zone Abyssal zone: dark bottom layer.: dark bottom layer. Very cold, little dissolved OVery cold, little dissolved O

22..



Effects of Human Activities on MarineEffects of Human Activities on Marine

Systems: Red AlertSystems: Red Alert

Human activitiesHuman activitiesare destroying or are destroying or

degrading manydegrading manyecological andecological andeconomic serviceseconomic services

provided by theprovided by theworld’s coastalworld’s coastalareas.areas.





Fig. 6-13, p. 136

Half of coastal wetlands lostto agriculture and urbandevelopment

Over one-third of mangroveforests lost to agriculture,development, and

aquaculture shrimp farms

Beaches eroding because of coastal development andrising sea level

Ocean bottom habitatsdegraded by dredging andtrawler fishing

At least 20% of coral reefsseverely damaged and 30–50% more threatened


Marine Ecosystems

FRESHWATER LIFEFRESHWATER LIFE



FRESHWATER LIFEFRESHWATER LIFE

ZONES(STOPPED)ZONES(STOPPED)

Freshwater life zonesFreshwater life zonesinclude:include: Standing (lentic)Standing (lentic)

water water such as lakes,such as lakes,ponds, and inlandponds, and inland

wetlands.wetlands. Flowing (lotic)Flowing (lotic)

systemssystems such assuch asstreams and rivers.streams and rivers.


Natural Capital



Natural Capital

Fig. 6-14, p. 136

Food

Drinking water

Irrigation water

Hydroelectricity

Transportation

corridors

Recreation

Employment

Climate moderation

Nutrient cycling

Waste treatment

Flood control

Groundwater

recharge

Habitats for many

species

Genetic resources

and biodiversity

Scientific

information

Economic

Services

Freshwater Systems

Ecological

Services

Lakes: Water FilledLakes: Water Filled



Lakes: Water-FilledLakes: Water-Filled

Depressions(STOPPED 6-7)Depressions(STOPPED 6-7)

Lakes are large natural bodies of standingLakes are large natural bodies of standingfreshwater formed from precipitation, runoff,freshwater formed from precipitation, runoff,and groundwater seepage consisting of:and groundwater seepage consisting of:

Littoral zoneLittoral zone (near shore, shallow, with rooted(near shore, shallow, with rootedplants).plants).

Limnetic zoneLimnetic zone (open, offshore area, sunlit).(open, offshore area, sunlit). Profundal zoneProfundal zone (deep, open water, too dark for (deep, open water, too dark for

photosynthesis).photosynthesis). Benthic zoneBenthic zone (bottom of lake, nourished by dead(bottom of lake, nourished by dead

matter).matter).



Lakes: Water-Filled DepressionsLakes: Water-Filled Depressions

During summer and winter in deep temperateDuring summer and winter in deep temperatezone lakes the become stratified intozone lakes the become stratified intotemperature layers and will overturn.temperature layers and will overturn.

This equalizes the temperature at all depths.This equalizes the temperature at all depths. Oxygen is brought from the surface to the lakeOxygen is brought from the surface to the lake

bottom and nutrients from the bottom are broughtbottom and nutrients from the bottom are broughtto the top.to the top.

What causes this overturning?What causes this overturning?



Lake in Winter Lake in Winter



Lake in SpringLake in Spring



Lake in Summer Lake in Summer



Lakes: Water-Filled DepressionsLakes: Water-Filled Depressions




Fig. 6-15, p. 137

Pondsnail

Benthic zone

Profundal zone

Limnetic zone

Sunlight

Blue-winged

teal

Muskrat

Plankton

BloodwormsNorthern

pike Yellowperch

Diving

beetle

Littoral zone

Painted

turtle

Green

frog



Effects of Plant Nutrients on Lakes:Effects of Plant Nutrients on Lakes:

Too Much of a Good ThingToo Much of a Good Thing

Plant nutrients from a lake’s environmentPlant nutrients from a lake’s environmentaffect the types and numbers of organisms itaffect the types and numbers of organisms itcan support.can support.






Plant nutrients from a lake’s environmentPlant nutrients from a lake’s environmentaffect the types and numbers of organisms itaffect the types and numbers of organisms it

can support.can support. Oligotrophic Oligotrophic (poorly nourished) lake: Usually(poorly nourished) lake: Usuallynewly formed lake with small supply of plantnewly formed lake with small supply of plantnutrient input.nutrient input.

Eutrophic Eutrophic (well nourished) lake: Over time,(well nourished) lake: Over time,sediment, organic material, and inorganicsediment, organic material, and inorganicnutrients wash into lakes causing excessive plantnutrients wash into lakes causing excessive plantgrowth.growth.





Cultural eutrophicationCultural eutrophication::

Human inputs of nutrients from the atmosphereHuman inputs of nutrients from the atmosphereand urban and agricultural areas can accelerateand urban and agricultural areas can accelerate

the eutrophication process.the eutrophication process.

Freshwater Streams and Rivers:Freshwater Streams and Rivers:



Freshwater Streams and Rivers:Freshwater Streams and Rivers:

From the Mountains to the OceansFrom the Mountains to the Oceans

Water flowing from mountains to the seaWater flowing from mountains to the seacreates different aquatic conditions andcreates different aquatic conditions and

habitats.habitats. Figure 6-17Figure 6-17



Fig. 6-17, p. 139

Source Zone

Rain and

snowLake Glacier

Rapids

Waterfall

Tributary

Flood plain Oxbow

lake

Salt marsh

Delta Deposited

sediment

Ocean

SedimentWater

Floodplain Zone

Transition Zone

Case Study:Case Study:



Case Study:Case Study:

Dams, Wetlands, Hurricanes,Dams, Wetlands, Hurricanes,

and New Orleansand New Orleans Dams and levees have been built to controlDams and levees have been built to control

water flows in New Orleans.water flows in New Orleans.

Reduction in natural flow has destroyedReduction in natural flow has destroyednatural wetlands.natural wetlands. Causes city to lie below sea-level (up to 3Causes city to lie below sea-level (up to 3

meters).meters). Global sea levels have risen almost 0.3 metersGlobal sea levels have risen almost 0.3 meters

since 1900.since 1900.

F h t I l d W tl d



Freshwater Inland Wetlands:Freshwater Inland Wetlands:

Vital SpongesVital Sponges

Inland wetlandsInland wetlandsact like naturalact like natural

sponges thatsponges thatabsorb and storeabsorb and storeexcess water excess water

from storms andfrom storms and

provide a varietyprovide a varietyof wildlifeof wildlifehabitats.habitats.




Freshwater Inland Wetlands:Freshwater Inland Wetlands:

Vital SpongesVital Sponges

Filter and degrade pollutants.Filter and degrade pollutants.

Reduce flooding and erosion by absorbingReduce flooding and erosion by absorbing

slowly releasing overflows.slowly releasing overflows. Help replenish stream flows during dryHelp replenish stream flows during dry

periods.periods.

Help recharge ground aquifers.Help recharge ground aquifers. Provide economic resources and recreation.Provide economic resources and recreation.

f



Impacts of Human Activities onImpacts of Human Activities on

Freshwater SystemsFreshwater Systems

Dams, cities, farmlands, and filled-in wetlands alter Dams, cities, farmlands, and filled-in wetlands alter and degrade freshwater habitats.and degrade freshwater habitats. Dams, diversions and canals have fragmented about 40%Dams, diversions and canals have fragmented about 40%

of the world’s 237 large rivers.of the world’s 237 large rivers. Flood control levees and dikes alter and destroy aquaticFlood control levees and dikes alter and destroy aquatic

habitats.habitats. Cities and farmlands add pollutants and excess plantCities and farmlands add pollutants and excess plant

nutrients to streams and rivers.nutrients to streams and rivers. Many inland wetlands have been drained or filled for Many inland wetlands have been drained or filled for

agriculture or (sub)urban development.agriculture or (sub)urban development.

I t f H A ti itiI t f H A ti iti



Impacts of Human Activities onImpacts of Human Activities on

Freshwater SystemsFreshwater Systems

These wetlandsThese wetlands

have beenhave beenditched andditched and

drained for drained for croplandcropland

conversion.conversion.

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