Aquatic EcosystemsAquatic Ecosystems Ch. 7 Ch. 7

BellringerBellringer

ObjectivesObjectives

DescribeDescribe the factors that determine the factors that determine where an organism lives in an aquatic where an organism lives in an aquatic ecosystem.ecosystem.

DescribeDescribe the littoral zone and the benthic the littoral zone and the benthic zone that make up a lake or pond.zone that make up a lake or pond.

DescribeDescribe two environmental functions of two environmental functions of wetlands.wetlands.

DescribeDescribe one threat against river one threat against river ecosystems.ecosystems.

I. Freshwater EcosystemsI. Freshwater Ecosystems

The types of organisms in an aquatic The types of organisms in an aquatic ecosystem are mainly determined by ecosystem are mainly determined by the water’s the water’s salinitysalinity – the amount of – the amount of dissolved salts the water containsdissolved salts the water contains

Aquatic ecosystems are divided into Aquatic ecosystems are divided into freshwater and marine ecosystemsfreshwater and marine ecosystems

Freshwater – lakes, ponds, rivers, Freshwater – lakes, ponds, rivers, streams and streams and wetlandswetlands – areas – areas periodically underwaterperiodically underwater

Marine – coastal areas of marshes, Marine – coastal areas of marshes, swamps, coral reefs, ocean swamps, coral reefs, ocean

A. Characteristics of Aquatic A. Characteristics of Aquatic EcosystemsEcosystems

Factors such as temperature, Factors such as temperature, sunlight, oxygen, and nutrients sunlight, oxygen, and nutrients determine which organisms live in determine which organisms live in which areas of the waterwhich areas of the water

Aquatic ecosystems contain several Aquatic ecosystems contain several types of organisms that are grouped types of organisms that are grouped by their location and adaptations by their location and adaptations

Aquatic OrganismsAquatic Organisms

PlanktonPlankton – organisms that float near – organisms that float near the surface of the waterthe surface of the water

-two types of plankton-two types of plankton phytoplanktonphytoplankton – microscopic – microscopic

plants, and plants, and zooplanktonzooplankton – – microscopic animalsmicroscopic animals

-phytoplankton produce most of -phytoplankton produce most of the food for an aquatic the food for an aquatic

ecosystem ecosystem

Aquatic OrganismsAquatic Organisms

NektonNekton – free-swimming organisms – free-swimming organisms such as fish, turtles, and whalessuch as fish, turtles, and whales

BenthosBenthos – bottom-dwelling – bottom-dwelling organisms such as mussels, worms, organisms such as mussels, worms, and barnaclesand barnacles

-most live attached to hard surfaces-most live attached to hard surfaces

Aquatic OrganismsAquatic Organisms

Decomposers – organisms that break Decomposers – organisms that break down dead organisms are also part down dead organisms are also part of aquatic ecosystemsof aquatic ecosystems

B. Lakes and PondsB. Lakes and Ponds Lakes, ponds, and wetlands can form Lakes, ponds, and wetlands can form

naturally where groundwater reaches naturally where groundwater reaches the Earth’s surfacethe Earth’s surface

Beavers can create ponds by Beavers can create ponds by damming up streamsdamming up streams

B. Lakes and PondsB. Lakes and Ponds Humans create artificial lakes by Humans create artificial lakes by

damming flowing rivers and streams damming flowing rivers and streams to use them for power, irrigation, to use them for power, irrigation, water storage, and recreationwater storage, and recreation

Lakes and ponds can be structured Lakes and ponds can be structured into horizontal and vertical zonesinto horizontal and vertical zones

Aquatic ZonesAquatic Zones

Horizontal Zones:Horizontal Zones: Littoral zoneLittoral zone – near the shore, – near the shore,

nutrient-rich, aquatic life is diverse nutrient-rich, aquatic life is diverse and abundantand abundant

-plants such as cattails and -plants such as cattails and reeds are rooted in the water and reeds are rooted in the water and upper leaves and stems emerge from upper leaves and stems emerge from the waterthe water

Littoral zoneLittoral zone plants with floating leaves like pond liliesplants with floating leaves like pond lilies

-in the open water – plants, algae, and -in the open water – plants, algae, and some bacteria perform photosynthesissome bacteria perform photosynthesis

-Open water deep areas there is too little -Open water deep areas there is too little light for photosynthesis – bacterial light for photosynthesis – bacterial decomposers live theredecomposers live there

-fish adapted to live in cool, dark areas -fish adapted to live in cool, dark areas

Limnetic ZoneLimnetic Zone

Open area of lakeOpen area of lakeNo rooted vegetationNo rooted vegetation

Horizontal Zones:Horizontal Zones:

Benthic zone – the bottom of a Benthic zone – the bottom of a pond or lakepond or lake

-inhabited by decomposers, insect -inhabited by decomposers, insect larvae, clamslarvae, clams

EutrophicationEutrophication

EutrophicationEutrophication – an increase in – an increase in plant nutrients in an aquatic plant nutrients in an aquatic ecosystemecosystem

-a lake that has a large amount -a lake that has a large amount of plant growth due to nutrients – of plant growth due to nutrients – eutrophic lakeeutrophic lake

Eutrophic LakeEutrophic Lake -as the amount of plants and algae grows, -as the amount of plants and algae grows,

the number of bacteria feeding on the the number of bacteria feeding on the decaying organisms also grows, these decaying organisms also grows, these bacteria use the oxygen dissolved in the bacteria use the oxygen dissolved in the lake, the reduced amount of oxygen lake, the reduced amount of oxygen

-kills oxygen-loving organisms-kills oxygen-loving organisms

-accelerated by runoff-accelerated by runoff

-runoff is precipitation that carries -runoff is precipitation that carries sewage, fertilizers, or animals waste sewage, fertilizers, or animals waste from land into bodies of waterfrom land into bodies of water

A Lake EcosystemA Lake Ecosystem

C. Freshwater WetlandsC. Freshwater Wetlands

Freshwater wetlands Freshwater wetlands - areas of - areas of land that are covered with land that are covered with freshwater for at least part of the freshwater for at least part of the yearyear

2 main types Freshwater 2 main types Freshwater WetlandsWetlands

MarshesMarshes – contain nonwoody plants – contain nonwoody plants SwampsSwamps – contain woody plants like – contain woody plants like

trees and shrubstrees and shrubs

Freshwater WetlandsFreshwater Wetlands Wetlands performs several important Wetlands performs several important

environmental functionsenvironmental functions

-act as filters or sponges because they -act as filters or sponges because they absorb and remove pollutants from water absorb and remove pollutants from water that flows through themthat flows through them

-controls flooding by absorbing extra water -controls flooding by absorbing extra water when rivers overflow which protects farms when rivers overflow which protects farms and urban and residential areas from and urban and residential areas from damagedamage

-used by fish for feeding and spawning -used by fish for feeding and spawning “nurseries”“nurseries”

-home for native and migratory wildlife-home for native and migratory wildlife

Freshwater WetlandsFreshwater Wetlands

the vegetation traps carbon that the vegetation traps carbon that would otherwise be released as would otherwise be released as carbon dioxidecarbon dioxide

-used to produce commercially -used to produce commercially important products like cranberriesimportant products like cranberries

Freshwater WetlandsFreshwater Wetlands

LocationLocation Most freshwater wetlands in the US Most freshwater wetlands in the US

are in the southeastare in the southeast

-Florida Everglades is the largest -Florida Everglades is the largest freshwater wetlandfreshwater wetland

-marshes tend to occur on low, flat -marshes tend to occur on low, flat lands that have little water lands that have little water movementmovement

-in shallow waters, plant such as -in shallow waters, plant such as reeds, rushes and cattails root in reeds, rushes and cattails root in sediment and stick out above the sediment and stick out above the water year roundwater year round

ZonesZones

benthic zones of marshes are benthic zones of marshes are nutrient richnutrient rich

-there are several kinds of marshes -there are several kinds of marshes each which is characterized by its each which is characterized by its salinitysalinity– brackish marshes have slightly brackish marshes have slightly

salty watersalty water– salt marshes contain saltier watersalt marshes contain saltier water

SwampsSwamps -occur on flat, poorly drained land often near -occur on flat, poorly drained land often near

streamsstreams

-dominated by woody shrubs or water-loving -dominated by woody shrubs or water-loving treestrees

-ideal habitat for many amphibians such as frogs -ideal habitat for many amphibians such as frogs or salamanders, and reptiles like the American or salamanders, and reptiles like the American alligatoralligator

Wetlands were previously considered to be Wetlands were previously considered to be wastelands that provided breeding grounds for wastelands that provided breeding grounds for insects and so insects and so

many have been drained, filled, and cleared for many have been drained, filled, and cleared for farms or developmentfarms or development

ImportanceImportance

-the important role of wetlands as purifiers -the important role of wetlands as purifiers of wastewater and flood prevention is now of wastewater and flood prevention is now recognizedrecognized

-they are vitally important for wildlife -they are vitally important for wildlife habitatshabitats

-law and the federal government protect -law and the federal government protect many wetlands and most states now many wetlands and most states now prohibit destruction of certain wetlandsprohibit destruction of certain wetlands

Environmental Functions of Environmental Functions of WetlandsWetlands

D. RiversD. Rivers Many rivers originate from snow melt in the Many rivers originate from snow melt in the

mountainsmountains

-At the headwaters, a river is usually cold and full -At the headwaters, a river is usually cold and full of oxygen, and runs swiftly through a shallow of oxygen, and runs swiftly through a shallow riverbedriverbed

-As the river flows down a mountain, it may -As the river flows down a mountain, it may become warmer, wider, and slower and decrease become warmer, wider, and slower and decrease in oxygenin oxygen

-Change with the land and climate through which -Change with the land and climate through which it flowsit flows

-Runoff may wash nutrients and sediment from -Runoff may wash nutrients and sediment from the surrounding land and can affect the growth the surrounding land and can affect the growth and health of the organisms in the riverand health of the organisms in the river

Life in a riverLife in a river Near the churning headwaters, Near the churning headwaters,

mosses anchor themselves to rocksmosses anchor themselves to rocks

Plankton do not live in the Plankton do not live in the headwaters because the current is headwaters because the current is too strong for them to floattoo strong for them to float

Trout and minnows are adapted to Trout and minnows are adapted to the cold, oxygen-rich headwatersthe cold, oxygen-rich headwaters

-powerful swimmers-powerful swimmers

Life in a riverLife in a river

Downstream plankton can float in the Downstream plankton can float in the warmer, calmer waterswarmer, calmer waters

-other plants can set roots in the -other plants can set roots in the plant’s sedimentplant’s sediment

-catfish and carp also live in the -catfish and carp also live in the calmer waterscalmer waters

Rivers in dangerRivers in danger -industries use river water in -industries use river water in

manufacturing processes and as manufacturing processes and as receptacles for wastereceptacles for waste

-runoff from the land puts pesticides -runoff from the land puts pesticides and other poisons into rivers and and other poisons into rivers and coats riverbeds with toxic sedimentscoats riverbeds with toxic sediments

-dams also alter the ecosystems in -dams also alter the ecosystems in and around a riverand around a river

II. Marine EcosystemsII. Marine Ecosystems Located in coastal areas and in the Located in coastal areas and in the

open oceanopen ocean

A. Coastal WetlandsA. Coastal Wetlands Coastal wetlandsCoastal wetlands – land areas that – land areas that

are covered by salt water for all or are covered by salt water for all or part of the timepart of the time

-provide habitat and nesting -provide habitat and nesting areas areas for many fish and wildlifefor many fish and wildlife

Coastal WetlandsCoastal Wetlands

-absorbs excess rain which protects -absorbs excess rain which protects areas from floodingareas from flooding

-filters out pollutants and sediments -filters out pollutants and sediments

-provide recreational areas for -provide recreational areas for boating , fishing, and huntingboating , fishing, and hunting

EstuaryEstuary EstuaryEstuary – an area in which fresh – an area in which fresh

water from a river mixes with salt water from a river mixes with salt water from the oceanwater from the ocean

-traps nutrients -traps nutrients -very productive ecosystems -very productive ecosystems

because they are constantly because they are constantly receiving fresh nutrientsreceiving fresh nutrients

Support many marine organisms Support many marine organisms because they have lots of nutrients because they have lots of nutrients and receive lots of sunlightand receive lots of sunlight

Threats to estuariesThreats to estuaries

-in populated areas estuaries were -in populated areas estuaries were used to dump wastesused to dump wastes

-used as building sites-used as building sites

-sewage, industrial waste containing -sewage, industrial waste containing toxic chemicals, agricultural runoff toxic chemicals, agricultural runoff containing pesticides and fertilizerscontaining pesticides and fertilizers

EstuariesEstuaries

Salt marshesSalt marshes

Salt marshesSalt marshes – develop in estuaries – develop in estuaries where rivers deposit a load of mineral-rich where rivers deposit a load of mineral-rich sedimentssediments

-support clams, fish, and aquatic birds-support clams, fish, and aquatic birds -acts as a nursery in which many species -acts as a nursery in which many species

of shrimp, crabs, and fishes find protection of shrimp, crabs, and fishes find protection when they are smallwhen they are small

-absorb pollutants and protect inland -absorb pollutants and protect inland areasareas

Quick LABQuick LAB

Mangrove swampsMangrove swamps

Mangrove swampsMangrove swamps – located along – located along coastal areas of tropical and coastal areas of tropical and subtropical zones dominated by subtropical zones dominated by mangrove treesmangrove trees

-protect coastline from erosion and -protect coastline from erosion and reduce the damage from stormsreduce the damage from storms

-breeding ground for about 2000 -breeding ground for about 2000 animals speciesanimals species

Mangrove swampsMangrove swamps

-filled with waste and destroyed in -filled with waste and destroyed in many parts of the worldmany parts of the world

Rocky shores have more plants and Rocky shores have more plants and animals than sandy shores doanimals than sandy shores do

-rocks provide anchorage for -rocks provide anchorage for seaweed and the many animals that seaweed and the many animals that live on them like sea anemones, live on them like sea anemones, mussels, spongesmussels, sponges

Sandy shores dry out when the tide Sandy shores dry out when the tide goes outgoes out

Barrier islandsBarrier islands

Barrier islandsBarrier islands – run parallel to the – run parallel to the shore, and the long thin islands help shore, and the long thin islands help protect the mainland and the coastal protect the mainland and the coastal wetlandswetlands

Math PracticeMath Practice

BellringerBellringer

ObjectivesObjectives

ExplainExplain why an estuary is a very why an estuary is a very productive ecosystem.productive ecosystem.

CompareCompare salt marshes and salt marshes and mangrove swamps.mangrove swamps.

DescribeDescribe two threats to coral reefs.two threats to coral reefs. DescribeDescribe two threats to ocean two threats to ocean

organisms.organisms.

Coral ReefsCoral Reefs

Corals live only in clear, warm salt Corals live only in clear, warm salt water where there is enough light for water where there is enough light for photosynthesis.photosynthesis.

B. Coral ReefsB. Coral Reefs Coral reefsCoral reefs – limestone ridges built – limestone ridges built

by tiny coral animals called by tiny coral animals called coral coral polypspolyps. .

-Coral polyps secrete skeletons of -Coral polyps secrete skeletons of limestone (calcium carbonate) which limestone (calcium carbonate) which slowly accumulates to form coral slowly accumulates to form coral reefs.reefs.

Coral ReefsCoral Reefs -thousands of plant and animal species -thousands of plant and animal species

live in the cracks and crevices of the coral live in the cracks and crevices of the coral reefsreefs

Coral reefs are among the most diverse Coral reefs are among the most diverse ecosystems on Earthecosystems on Earth

Corals live only in clear and warm salt Corals live only in clear and warm salt water where there is enough light for water where there is enough light for photosynthesisphotosynthesis

-found in shallow tropical seas-found in shallow tropical seas

Coral ReefsCoral Reefs

-only the outer layer or a reef -only the outer layer or a reef contains living corals which build contains living corals which build their rock homes with the help of their rock homes with the help of photosynthetic algae photosynthetic algae

Corals use tentacles to capture their Corals use tentacles to capture their preyprey

Disappearing coral reefsDisappearing coral reefs

-productive but fragile ecosystems-productive but fragile ecosystems

-27% are in danger of destruction -27% are in danger of destruction from human activitiesfrom human activities

-if the water is too hot or too -if the water is too hot or too cold or if fresh water drains into the cold or if fresh water drains into the water surrounding the reef, the water surrounding the reef, the corals may diecorals may die

Disappearing coral reefsDisappearing coral reefs

-if the water is too muddy, polluted, -if the water is too muddy, polluted, or too high in nutrients the algae that or too high in nutrients the algae that live within the coral will live within the coral will

die or grow out of control killing the die or grow out of control killing the coralscorals

oil spills, sewage, pesticide, and silt oil spills, sewage, pesticide, and silt runoff have been linked to coral reef runoff have been linked to coral reef destructiondestruction

Disappearing coral reefsDisappearing coral reefs

overfishing can decimate the fish overfishing can decimate the fish populations and upset the balance of populations and upset the balance of a reef’s ecosystema reef’s ecosystem

-because coral reefs grow slowly a -because coral reefs grow slowly a reef may not be able to repair itself reef may not be able to repair itself after chunks of coral are destroyed after chunks of coral are destroyed by divers, fisheries, shipwrecks, ships by divers, fisheries, shipwrecks, ships dropping anchor, or people breaking dropping anchor, or people breaking off pieces of itoff pieces of it

C. OceansC. Oceans Much of the ocean’s life is Much of the ocean’s life is

concentrated in the top 100m or 330 concentrated in the top 100m or 330 ft because that is how far sunlight ft because that is how far sunlight can penetratecan penetrate

most life is in the shallow coastal most life is in the shallow coastal waterswaters

Plants and animals of the oceanPlants and animals of the ocean

OceansOceans in the open ocean phytoplankton grows in the open ocean phytoplankton grows

where there is enough light and nutrientswhere there is enough light and nutrients

-the open ocean is one of the least -the open ocean is one of the least productive of all ecosystemsproductive of all ecosystems

-zooplankton feed on phytoplankton, these -zooplankton feed on phytoplankton, these include jellyfish, tiny shrimp, larvae of fish include jellyfish, tiny shrimp, larvae of fish and bottom-dwelling organisms such as and bottom-dwelling organisms such as oysters and lobsters oysters and lobsters

Plants and Animals of OceansPlants and Animals of Oceans

OceansOceans fish feed on the plankton as to fish feed on the plankton as to

marine mammals like whalesmarine mammals like whales

-depths of the ocean are perpetually -depths of the ocean are perpetually dark so most food consists of dead dark so most food consists of dead organisms that fall from the surfaceorganisms that fall from the surface

-decomposers, filter-feeders, and the -decomposers, filter-feeders, and the organisms that eat them live in these organisms that eat them live in these deep areasdeep areas

Threats to the oceanThreats to the ocean

-Most ocean pollution arises from -Most ocean pollution arises from activities on landactivities on land

-plant nutrients runoff the land’s -plant nutrients runoff the land’s fertilized fields may cause algal fertilized fields may cause algal blooms some of which are poisonousblooms some of which are poisonous

-industrial waste and sewage discharged -industrial waste and sewage discharged into rivers is the biggest source of coastal into rivers is the biggest source of coastal pollution pollution

-overfishing and certain fishing methods -overfishing and certain fishing methods are also destroying some fish populationsare also destroying some fish populations

trawl nets can entangle organisms that are trawl nets can entangle organisms that are larger than net holes such as dolphins and larger than net holes such as dolphins and sea sea

turtles who need to breathe air can drown turtles who need to breathe air can drown in the netsin the nets

discarded fishing lines in the ocean can discarded fishing lines in the ocean can strangle and kill fish and sealsstrangle and kill fish and seals

Arctic and Antarctic EcosystemsArctic and Antarctic Ecosystems

arctic ecosystems depend on marine arctic ecosystems depend on marine ecosystems because nearly all the ecosystems because nearly all the food comes from the oceanfood comes from the ocean

Arctic OceanArctic Ocean Arctic Ocean is rich in nutrients from Arctic Ocean is rich in nutrients from

the surrounding land masses and it the surrounding land masses and it supports large populations of supports large populations of

plankton which feeds a rich diversity plankton which feeds a rich diversity of fish in the open water and under of fish in the open water and under the icethe ice

fish are food for ocean birds, whales, fish are food for ocean birds, whales, and sealsand seals

fish and seals also provide food for fish and seals also provide food for polar bears and people on landpolar bears and people on land

AntarcticAntarctic

Antarctic is the only continent never Antarctic is the only continent never colonized by humanscolonized by humans

governed by an international governed by an international commission and is used mainly for commission and is used mainly for researchresearch

No Polar BearsNo Polar Bears

AntarcticAntarctic

during the summer a few plants grow during the summer a few plants grow at the rocky edges of the continentat the rocky edges of the continent

-plankton form the basis of this food -plankton form the basis of this food web too which nourishes large web too which nourishes large numbers of fish, whales and birds numbers of fish, whales and birds such as such as penguinspenguins