Section 7-1Section 7-1

Aquatic EnvironmentsAquatic Environments

Core Case Study:Core Case Study:Why Should We Care About Coral Reefs?Why Should We Care About Coral Reefs?

Coral reefs form in Coral reefs form in clear, warm coastal clear, warm coastal waters of the waters of the tropics and tropics and subtropics.subtropics. Formed by Formed by

massive colonies massive colonies of polyps.of polyps.

Finding Nemo

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 Coral Reefs?Why Should We Care About Coral Reefs?

Help moderate atmospheric temperature by Help moderate atmospheric temperature by removing COremoving CO22 from the atmosphere. from the atmosphere.

Act as natural barriers that help protect 14% Act as natural barriers that help protect 14% of the world’s coastlines from erosion by of the world’s coastlines from erosion by battering waves and storms.battering waves and storms.

Provide habitats for a variety of marine Provide habitats for a variety of marine organisms.organisms.

AQUATIC ENVIRONMENTSAQUATIC ENVIRONMENTS Saltwater and freshwater aquatic life zones Saltwater and freshwater aquatic life zones

cover almost three-fourths of the earth’s cover almost three-fourths of the earth’s surfacesurface

Figure 6-2Figure 6-2

AQUATIC ENVIRONMENTSAQUATIC ENVIRONMENTS

Figure 6-3Figure 6-3

WATER’S IMPORTANCE, WATER’S IMPORTANCE, AVAILABILITY, AND RENEWALAVAILABILITY, AND RENEWAL

Comparison of Comparison of population sizes population sizes and shares of the and shares of the world’s freshwater world’s freshwater among the among the continents.continents.

Figure 14-2Figure 14-2

Categorization of Aquatic BiomesCategorization of Aquatic Biomes Physical characteristicsPhysical characteristics• Salinity Salinity

• DepthDepth

• Water flowWater flow

Temperature (not used for categorization)Temperature (not used for categorization)

Types of Biomes Types of Biomes Freshwater Freshwater • Streams Streams • RiversRivers• LakesLakes• WetlandsWetlands

Marine (saltwater)Marine (saltwater)• EstuariesEstuaries• Coral Reefs Coral Reefs • Open Ocean Open Ocean

What Kinds of Organisms Live in What 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 compounds Decomposers: breakdown organic compounds

(mostly bacteria).(mostly bacteria).

PhytoplanktonPhytoplankton Description – small drifting plantsDescription – small drifting plants Niche – they are producers that support Niche – they are producers that support

most aquatic food chainsmost aquatic food chains Example – cyanobacteria & many types of Example – cyanobacteria & many types of

algaealgae

ZooplanktonZooplankton Description – herbivores that feed on Description – herbivores that feed on

phytoplankton or other zooplanktonphytoplankton or other zooplankton Niche – food stock for larger consumersNiche – food stock for larger consumers Example – krill; small crustaceansExample – krill; small crustaceans

NektonNekton Description – larger, strong-Description – larger, strong-

swimming consumersswimming consumers Niche – top consumers in the Niche – top consumers in the

aquatic ecosystemaquatic ecosystem Example – fish, turtles, and whalesExample – fish, turtles, and whales

BenthosBenthos

Description – bottom-dwelling Description – bottom-dwelling creaturescreatures

Niche – primary consumers, Niche – primary consumers, decomposersdecomposers

Example – barnacles, oysters, and Example – barnacles, oysters, and lobsterslobsters

Life in most aquatic systems is found in Life in most aquatic systems is found in surface, 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.

The Ocean

Life in LayersLife in Layers

Section 7-2Section 7-2

Saltwater Life ZonesSaltwater Life Zones

SALTWATER LIFE ZONESSALTWATER LIFE ZONES The oceans that occupy The oceans that occupy

most of the earth’s surface most of the earth’s surface provide many ecological provide many ecological and economic services.and economic services.

Scientists estimate that Scientists estimate that marine systems provide marine systems provide $21 trillion in goods and $21 trillion in goods and services per year – 70% services per year – 70% more than terrestrial more than terrestrial ecosystems.ecosystems.

Figure 6-4Figure 6-4

The Coastal Zone: The Coastal Zone: The coastal zoneThe coastal zone• The warm, nutrient-rich, shallow water The warm, nutrient-rich, shallow water • Extends from the high-tide mark on land to Extends from the high-tide mark on land to

the gently sloping, shallow edge of the the gently sloping, shallow edge of the continental shelf.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 the world’s ocean area

• Contains 90% of all marine species.Contains 90% of all marine species. Provides numerous ecological and economic Provides numerous ecological and economic

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

The Coastal ZoneThe Coastal Zone

Figure 6-5Figure 6-5

Estuaries and Coastal Wetlands: Estuaries and Coastal Wetlands:

Estuaries include river Estuaries include river mouths, inlets, bays, mouths, inlets, bays, sounds, salt marshes in sounds, salt marshes in temperate zones and temperate zones and mangrove forests in mangrove forests in tropical zones.tropical zones.

Figure 6-7Figure 6-7

Estuaries and Coastal Wetlands: Estuaries and Coastal Wetlands: Estuaries and coastal marshes provide Estuaries 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 waves and Reduce storm damage by absorbing waves and

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

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

Rocky and Sandy Shores: Rocky and Sandy Shores:

Organisms experiencing daily low and high Organisms experiencing daily low and high tides have a number of ways to survive under tides have a number of ways to survive under harsh and changing conditions.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 low Intertidal 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 in Organisms in intertidal zone intertidal zone develop specialized develop specialized niches to deal with niches to deal with daily changes in:daily changes in: TemperatureTemperature SalinitySalinity Wave actionWave action

Figure 6-9Figure 6-9

Threats to Threats to Coral Reefs:Coral Reefs:Increasing Increasing StressesStresses

Biologically Biologically diverse and diverse and productive coral productive coral reefs are being reefs are being stressed by stressed by human activities.human activities.

Figure 6-11Figure 6-11

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

Natural Capital Degradation

Coral Reefs

Effects of Human Activities on Marine Effects of Human Activities on Marine Systems: Red AlertSystems: Red Alert

Human activities Human activities are destroying or are destroying or degrading many degrading many ecological and ecological and economic services economic services provided by the provided by the world’s coastal world’s coastal areas.areas.

Figure 6-13Figure 6-13

Section 7-3Section 7-3

Freshwater Life ZonesFreshwater Life Zones

FRESHWATER LIFE ZONESFRESHWATER LIFE ZONES

Freshwater life zones Freshwater life zones include:include: Standing (lentic) Standing (lentic)

waterwater such as lakes, such as lakes, ponds, and inland ponds, and inland wetlands.wetlands.

Flowing (lotic) Flowing (lotic) systemssystems such as such as streams and rivers. streams and rivers.

Figure 6-14Figure 6-14

Flowing Water EcosystemsFlowing Water Ecosystems

Because of different environmental Because of different environmental conditions in each zone, a river is a conditions in each zone, a river is a system of different ecosystems.system of different ecosystems.

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

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 sea Water flowing from mountains to the sea creates different aquatic conditions and creates different aquatic conditions and habitats. habitats.

Figure 6-17Figure 6-17

Headwater Stream CharacteristicsHeadwater Stream Characteristics

A narrow zone of cold, clear water that A narrow zone of cold, clear water that rushes over waterfalls and rapids. Large rushes over waterfalls and rapids. Large amounts of oxygen are present. Fish amounts of oxygen are present. Fish are also present. Ex. trout.are also present. Ex. trout.

Downstream CharacteristicsDownstream Characteristics

Slower-moving water, less oxygen, Slower-moving water, less oxygen, warmer temperatures, and lots of warmer temperatures, and lots of algae and cyanobacteria.algae and cyanobacteria.

Energy SourceEnergy Source

GravityGravity

Standing Water Standing Water EcosystemsEcosystems

Lakes, ponds, etc.Lakes, ponds, etc.

Life in LayersLife in Layers

Life in most aquatic systems is found in Life in most aquatic systems is found in surface, 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.

Lakes: Water-Filled DepressionsLakes: Water-Filled Depressions

Lakes are large natural bodies of standing Lakes are large natural bodies of standing freshwater formed from precipitation, runoff, and freshwater formed from precipitation, runoff, and groundwater seepage consisting of:groundwater seepage consisting of: Littoral zoneLittoral zone (near shore, shallow, with rooted plants).(near shore, shallow, with rooted 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).

Littoral ZoneLittoral Zone

A shallow area near the shore, to the A shallow area near the shore, to the depth at which rooted plants stop depth at which rooted plants stop growing. Ex. frogs, snails, insects, growing. Ex. frogs, snails, insects, fish, cattails, and water lilies.fish, cattails, and water lilies.

Limnetic ZoneLimnetic Zone

Open, sunlit water that extends to the Open, sunlit water that extends to the depth penetrated by sunlight.depth penetrated by sunlight.

Profundal ZoneProfundal Zone

Deep, open water where it is Deep, open water where it is too dark for photosynthesis.too dark for photosynthesis.

Lakes: Water-Filled DepressionsLakes: Water-Filled Depressions

Figure 6-15Figure 6-15

Lakes: Water-Filled DepressionsLakes: Water-Filled Depressions

During summer and winter in deep temperate During summer and winter in deep temperate zone lakes the become stratified into zone lakes the become stratified into temperature 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 lake Oxygen is brought from the surface to the lake

bottom and nutrients from the bottom are brought bottom and nutrients from the bottom are brought to the top.to the top.

What causes this overturning?What causes this overturning?

Thermal StratificationThermal Stratification

The temperature difference in deep The temperature difference in deep lakes where there are warm lakes where there are warm summers and cold winters.summers and cold winters.

Causes of Thermal StratificationCauses of Thermal Stratification

During the summer, During the summer, lakes become stratified lakes become stratified into different into different temperature layers that temperature layers that resist mixing because resist mixing because summer sunlight warms summer sunlight warms surface waters, making surface waters, making them less dense.them less dense.

ThermoclineThermocline

The middle layer The middle layer that acts as a barrier that acts as a barrier to the transfer of to the transfer of nutrients and nutrients and dissolved oxygen.dissolved oxygen.

Fall TurnoverFall Turnover

As the temperatures begin to drop, the As the temperatures begin to drop, the surface layer becomes more dense, and surface layer becomes more dense, and it sinks to the bottom. This mixing it sinks to the bottom. This mixing brings nutrients from the bottom up to brings nutrients from the bottom up to the surface and sends oxygen to the the surface and sends oxygen to the bottom.bottom.

Spring TurnoverSpring Turnover

As top water warms and ice melts, As top water warms and ice melts, it sinks through and below the it sinks through and below the cooler, less dense water, sending cooler, less dense water, sending oxygen down and nutrients up.oxygen down and nutrients up.

Freshwater WetlandsFreshwater Wetlands

Freshwater Inland Wetlands: Freshwater Inland Wetlands: Vital SpongesVital Sponges

Inland wetlands act Inland wetlands act like natural like natural sponges that sponges that absorb and store absorb and store excess water from excess water from storms and provide storms and provide a variety of wildlife a variety of wildlife habitats.habitats.

Figure 6-18Figure 6-18

Freshwater Inland Wetlands: Freshwater Inland Wetlands: Vital SpongesVital Sponges

Filter and degrade pollutants.Filter and degrade pollutants. Reduce flooding and erosion by Reduce flooding and erosion by

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

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

recreation.recreation.

MarshesMarshes

An area of temporarily flooded, often An area of temporarily flooded, often silty land beside a river or lake.silty land beside a river or lake.

SwampsSwamps

A lowland region permanently covered A lowland region permanently covered with water.with water.

Prairie PotholesPrairie Potholes

These are depressions that hold water out These are depressions that hold water out on the prairie, especially up north in on the prairie, especially up north in Canada. It is a very good duck habitat.Canada. It is a very good duck habitat.

Peat Moss BogPeat Moss Bog A wet area that over time fills in (the last A wet area that over time fills in (the last

stage of succession is peat moss). It can stage of succession is peat moss). It can be very deep. In Ireland, they burn this for be very deep. In Ireland, they burn this for wood.wood.

Importance of freshwater wetlandsImportance of freshwater wetlands

They filter & purify water.They filter & purify water.

Habitat for many animals and Habitat for many animals and plants.plants.

Historical AspectsHistorical Aspects

Developers and farmers want Congress to Developers and farmers want Congress to revise the definition of wetlands. This would revise the definition of wetlands. This would make 60-75% of all wetlands unavailable for make 60-75% of all wetlands unavailable for protection. protection.

The Audubon Society estimates that The Audubon Society estimates that wetlands provide water quality protection wetlands provide water quality protection worth $1.6 billion per year, and they say if worth $1.6 billion per year, and they say if that wetlands are destroyed, the U.S. would that wetlands are destroyed, the U.S. would spend $7.7 billion to $31 billion per year in spend $7.7 billion to $31 billion per year in additional flood-control costs.additional flood-control costs.

EstuariesEstuaries

Estuary DefinitionEstuary DefinitionA partially enclosed area of coastal A partially enclosed area of coastal

water where sea water mixes with water where sea water mixes with freshwater.freshwater.

Salt MarshesSalt Marshes The ground here is saturated with water and The ground here is saturated with water and

there is little oxygen, so decay takes place there is little oxygen, so decay takes place slowly. It has a surface inlet and outlet, and slowly. It has a surface inlet and outlet, and contains many invertebrates. It is also the contains many invertebrates. It is also the breeding ground for many ocean animals. Ex. breeding ground for many ocean animals. Ex. crabs and shellfish.crabs and shellfish.

Mangrove ForestsMangrove Forests These are along warm, These are along warm,

tropical coasts where there is tropical coasts where there is too much silt for coral reefs to too much silt for coral reefs to grow. It is dominated by salt-grow. It is dominated by salt-tolerant trees called tolerant trees called mangroves (55 different mangroves (55 different species exist). It also helps to species exist). It also helps to protect the coastline from protect the coastline from erosion and provides a erosion and provides a breeding nursery for some breeding nursery for some 2000 species of fish, 2000 species of fish, invertebrates, and plants.invertebrates, and plants.

                                  

Importance of EstuariesImportance of Estuaries

Just one acre of estuary provides $75,000 Just one acre of estuary provides $75,000 worth of free waste treatment, and has a value worth of free waste treatment, and has a value of about $83,000 when recreation and fish for of about $83,000 when recreation and fish for food are included. food are included.

Prime Kansas farmland has a top value of Prime Kansas farmland has a top value of $1,200 and an annual production value of $1,200 and an annual production value of $600.$600.

Overview QuestionsOverview Questions What are the basic types of aquatic life zones What are the basic types of aquatic life zones

and what factors influence the kinds of life they and what factors influence the kinds of life they contain?contain?

What are the major types of saltwater life zones, What are the major types of saltwater life zones, and how do human activities affect them?and how do human activities affect them?

What are the major types of freshwater life What are the major types of freshwater life zones, and how do human activities affect zones, and how do human activities affect them?them?