Watersheds and Wetlands

Watersheds and Wetlands

Chapter 1

Big Blue Marble¾ of the Earth’s surface covered in water

Water is the most common substance on earth and the MOST IMPORTANT

Where is the water?If the world’s total water supply were in a 200 L drum. . .

• Ocean Water: 97.2%• Glaciers and ice caps: 2.11%

• Groundwater: 0.62%

• Lakes: 0.009%

• Atmospheric moisture: 0.001%

• Rivers: 0.0001%

Fresh Water:

Water can exist as:Solid = Ice

Liquid = Water

Gas = Steam

Changes of State

S

G

L

Depos

ition

Condensation

Solidification

Vaporization

Subli

mation

Melting

Several of these processes are part of the:

WATERCYCLE

Also known as the Hydrologic Cycle

• Evaporation: Change of statefrom liquid to gas over a periodof time at various temperatures• Transpiration: Plants releasewater vapor from their leaves • Precipitation: liquid or solid

water that falls from atmosphere to Earth

• In PA… ½ of our annual 42” rainfall is returned to atmosphere via evaporation and transpiration

• Runoff: Precipitation that runs off the ground back into streams, rivers or oceans• Groundwater: Precipitation thatseeps into the ground and isstored beneath the Earth’ssurface• 22% of Earth’s freshwater is groundwater• In PA.. 1 billion gallons of groundwater is used EACH DAY in households, industries, agriculture and mining

Groundwater Contamination

Groundwater Contamination• Contaminants from natural

sources• As water travels over soil and rocks

it dissolves certain minerals and carries them away

• “Hard water” is water that has highconcentrations of Calcium• High concentrations of iron makewater “brown” and metallic tasting • High concentrations of hydrogen sulfide

gives water “rotten egg” odor and taste

Groundwater Contamination• Contaminants from human activities

• As population gets more dense and we “take over” more and more space wecontaminate the water supply

• Poorly installed and maintained septics• Pesticides and fertilizers used on farms

and lawns• Landfills, chemical spills, leaking storage

tanks, salts used on icy roads

Stream Characteristics

Water Flow OrderPrecipitation falls

Water travels along “rills” which are grooves eroded in

the ground by water over time

Rills merge and empty into creeks and streams

Water Flow Order

Creeks and streams feed into rivers

Rivers flow into oceans

The place where a stream or river begins is called

it’s source

The place where a stream or river ends by

flowing into another body of water is called it’s

mouth

Laminar flow: occurs when water moves in straight paths that are parallel to the stream’s channel or bed. Very

little mixingTurbulent flow: occurs when water moves in

tiny circular paths as it flows downstream. Much

more mixing

A stream’s velocity, or the distance

water flows during some period of

time, determines the type of flow

LOW VELOCITY (move slowly)

streams have mostly Laminar flow

HIGH VELOCITY (move quickly)

streams have mostly Turbulent flow

Sediment LoadDissolved Load Suspended

LoadBed Load

Sediment that is “dissolved” in solution

Sediment that is “suspended” in solution

Sediment that is carried along the

bottom of the channelEarth materials that dissolve in the water as it runs over rocks

and soil

Materials such as silt and clay that is carried by water but does not

dissolve in it

Larger materials such as sand, gravel,

pebbles and boulders

Comes from ground water that returns to the Earth’s surface

Constitutes the majority of the river or streams

load comes from banks as water erodes

Sand and gravel “skip” along bed

pebbles and boulders roll and slide along

bed

Sediment LoadSediment: particles that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid.

Sediment is carried in streams and rivers in three ways

Watershed

Also known as a drainage basin

Region OF LAND that contributes water to a stream, lake or other body of water

Watersheds are surrounded by divides

Divide: any ridge between two streams along which precipitation

runs off.The Continental Divide-splits North

America and some of Central America in two watersheds

Watersheds can also be very small

Five of the Major Watersheds in PAPA State water plan: 104

watershedsWe will be focusing on 5 that are considered to be Major Watersheds

Great Lakes Basin (Erie and Genesee)Ohio River BasinSusquehanna/Chesapeake BasinPotomac BasinDelaware Basin

Great Lakes BasinOnly about 1% of this basin

actually lies in PA

Divided into two sub-basins; Erie Basin and Genesee Basin

Rivers and streams in both basins drain to the North into the Great

Lakes

Ohio River BasinPA’s second largest watershed

Ohio River is largest in this watershed

Susquehanna/Chesapeake BasinPA’s largest watershedCovers 46% of the state

Largest river: Susquehanna

Potomac BasinPotomac River does not flow

through PA PA’s Shenandoah River is the

Potomac River’s largest tributary

Delaware Basin 3rd largest watershed in PA

Delaware river and it’s tributaries supply most of New York City’s

freshwater needs

Stream Biology

Ecosystem: all the plants, animals and micro organisms in an area that function together with the non-living factors of that environment

Streams and Rivers are aquatic ecosystems

AlgaePlant like organisms (Protists)Producers: Make their own food

(also known as autotrophs)Use energy from sun and dissolved

nutrients to make foodBase of most aquatic food chains

Animal Like ProtistsSimple organisms that have same

characteristics as animalsEat bacteria, sediments that contain

bacteria and algaeSaprotrophs: feed on decayed

organic materialRaptors: protists that eat other protists

CiliatesParamecia

Amoeba

InvertebratesOrganisms that do not have a back

boneInsects: Flies and beetles found in

nearly every stream or riverLarval stage lives in waterAdults: Most live on land surrounding stream; some live on water surface(water striders)

Invertebrates

Shredders: Eat tissue of other organisms; organic matter; wood(bite and chew)

Predators: ingest prey whole or piercetissues and suck out fluids

FliesSome shreddersSome predators

BeetlesSome saprotrophsSome predators

Freshwater mollusks and some aquatic worms Spend entire lives in waterMost feed on algae and plants(Primary consumers, herbivores

eat producers)Some eat other animals

(Secondary consumers, carnivores)Some eat both plants and animals

(Secondary consumers, omnivores)

Vertebrates

Organisms that have a back boneAmphibians; such as salamanders,

frogs, turtles, newtsFish; such as pike, trout, pickerel,

bullheads, bluegill, bass, sunfishcatfish, perch and suckers

Amphibians

Depend on water at various stages of their life cyclesMost adults live on landMost adults are predators

FishSome are primary consumers of algae

•Grazers•Strainers•Suckers

Some are predatorsSome are detritivores: feed by

shredding sediments or filter food directly from sediments

Class Activity:Identifying Macro

Invertebrates!!http://people.virginia.edu/~sos-iwla/Stream-Study/Key/MacroKeyIntro.HTML

Notes on Factors that Affect Freshwater Ecosystems

WetlandsWetland: an area that contains unique types of soil, is home to plants adapted to the wet environment, and contains water all year or certain times during the year

Types of wetlandsSoil Plants Organisms

Bogvery acidic

Little oxygen

Scrub-shrub wetland

Decomposed plant material called peat or muck

Predominantly mosses; shrubs;

evergreens; water lilies; cranberries;

blueberriesTrees less than 20

feet tall

Few fishFrogs TurtlesInsects

Certain birds

SwampForested wetlands

Drains slowlySome; nutrient rich

but not all

Classified by trees:Conifers; cedars,

pines, sprucesHardwoods; maples

willows, aspens, birches, elms, oaksTrees can be more

than 20 feet tall

White tail deerraccoonsheronsegrets

woodpeckersSnakes, frogs

turtles

Types of wetlandsSoil Plants Organisms

MarshForms at mouth of river or areas of

poor drainageEmergent wetlands

Nutrient rich GrassesSedges

BulrushesCattails

Plants rooted in soil but emerge above

water

BeaversFrogsTurtles

Raccoons Muskrats

OpossumsBirds, insects

Wetlands at work Habitat: home to many species

many threatened or endangeredFood Factories: plants in wetlands serve base of wetland food websSpawning Grounds and Nurseries:Many organisms reproduce hereCycling Nutrients: plants use carbon

dioxide, produce oxygen, cyclenitrogen and phosphorus

Wetlands at work Buffer Zones: act as “natural sponges”, absorb excess runoff and release it back to environment slowly; Wetlands in coastal areas absorb energy of waves and stormsprotecting mainlandPollution Control: Reduce sediment by slowing water movement; many wetland plants store carbon insteadof polluting air with carbon dioxide

Factors That Affect Wetlands and WatershedsHuman Activities:

•Agriculture•Urbanization and construction•Mining•Industry•Waste Disposal

Agriculture:•Harvesting•Irrigation ditches•Animal wastes•Overgrazing (erosion of soil) which

increases sediment that runs off •Chemicals used in pesticides and

fertilizers

Urbanization and Construction•Covering soil with concrete increases

runoff that carries pollutants•Construction of roads and bridges overwetlands; increases runoff and restricts movements of organisms•Paints, cleaners, salt, herbicides used

along roads damage wetlands by increasing turbidity, lowering pH, and decreasing dissolved oxygen

•Canals, ditches, levees divert water from it’s natural flow

Mining:•Mining of substances directly from

wetlands such as phosphorus andpeat

•Mining of rocks and minerals: acid drainage; heavy metals; sedimentIndustry:•Construction; reduces wetland acreage•Pollutants•Water intake, draining of wetlands•Water release, thermal pollution which

can lead to algal blooms

Waste Disposal:•Landfills: solid waste; toxic leakage•Sludge and Wastewater Treatment;

•Introduce of biological pathogensto wetlands

•Rich in nitrogen and phosphoruswhich cause Algal blooms

Factors That Affect Wetlands and WatershedsNatural Events:

•Floods•Erosion and Deposition•Drought•Volcanic Eruptions•Fires•Wind•Global Climate Change

Floods:•Positive impact:

•Move nutrients and organic materials downstream

•Deposit silt into river banks•Change shape and size of river channel;

form new channels•Negative impact:

•Destroy riverbanks•Carry organisms away from natural habitat•Landslides; increases sediment

Erosion and Deposition•Erosion, sediment movement, and deposition all happen as water flows over land•Changes in precipitation causes more erosion which can change size and shape of stream or river channel•Channel changes affects velocity, discharge

and stream biology

Drought•Drought: period in which the amount of precipitation that falls in and area is lower than normal•Reduce the volume of the water

•Lower volume affects clarity, salinity, temperature, pH and amount of sediment•Some bodies of water disappear; causing loss of breeding and feeding grounds

Volcanic Eruptions

•Massive mudslides that cutoff streams and rivers•Vegetation loss changes stream biology•Ash changes pH of water and increases turbidity•Temperature changes and ash kill organisms

Fires•Damage or destroy vegetation; causing increase in runoff and erosion•Loss of habitat•Increase temperature of water•Can be BENEFICIAL; pine tree reproduction

Wind•Carry and drop sediment•Affects evaporation of water

Global Climate Changes•Natural large scale changes in climate occur about every 10,000 years•Cooler climate; freshwater locked in ice and glaciers•Warmer climate; melt off increases sea level; causes flooding; causes salt water to move into fresh water wetlands

•Changes the salinity of wetlands•Salt-tolerant species replace freshwater organisms•Vegetation covered and dies changing wetlands into open water