Pennsylvania Drainage PatternsPennsylvania Drainage PatternsMany drainage patterns in the west are dendritic because of massive sedimentary rock Many drainage patterns in the west are dendritic because of massive sedimentary rock

layers.layers.

The drainage patterns in the south -central part of the state tend to be rectangular The drainage patterns in the south -central part of the state tend to be rectangular primarily because of ancient faults the formed during the formation of the Appalachian primarily because of ancient faults the formed during the formation of the Appalachian Mountains.Mountains.

The south-east drainage patterns are trellis patterns. These patterns form as a result of The south-east drainage patterns are trellis patterns. These patterns form as a result of folding that occurred when the Appalachian’s formed. Erosion of the rock material left folding that occurred when the Appalachian’s formed. Erosion of the rock material left resistant rock layers alternating with non-resistant rock layers. Streams now flow in the resistant rock layers alternating with non-resistant rock layers. Streams now flow in the non-resistant rock valleys. non-resistant rock valleys.

In Potter County there is an unnamed hill marks the boundary between three of In Potter County there is an unnamed hill marks the boundary between three of Pennsylvania’s major drainage basins. Pennsylvania’s major drainage basins.

1.One drains to the north through the St. Lawrence River1.One drains to the north through the St. Lawrence River

2. A second drains S-W to the Gulf of Mexico2. A second drains S-W to the Gulf of Mexico

3. The Third drains east to the Atlantic3. The Third drains east to the Atlantic

Diagram View

More realistic view

PA watershedsPA watershedsThe state’s freshwater systems are divided into The state’s freshwater systems are divided into 104 watersheds.104 watersheds.

  Five Major WatershedsFive Major Watersheds1 ) 1 ) Great Lakes Basin Great Lakes Basin – only 1% of this basin lies within PA. – only 1% of this basin lies within PA.

Sub-basinsSub-basins• Erie Basin – includes Conneaut, Elk, and Walnut CreeksErie Basin – includes Conneaut, Elk, and Walnut Creeks• Genesee Basin - drains into Lake OntarioGenesee Basin - drains into Lake Ontario

Five Major WatershedsFive Major Watersheds2) 2) Ohio River Basin Ohio River Basin – PA’s 2– PA’s 2ndnd largest largest watershed. Headwaters in the Ohio River and watershed. Headwaters in the Ohio River and Allegheny & Mongahela Rivers that meet in Allegheny & Mongahela Rivers that meet in Pittsburgh.Pittsburgh.

This basin includesThis basin includes::• Tionesta Creek, Mahoning Creek, Stony Creek Tionesta Creek, Mahoning Creek, Stony Creek

River, the Lower and Upper Youghiogheny River, the Lower and Upper Youghiogheny Rivers, Beaver River, and the Upper Ohio Rivers, Beaver River, and the Upper Ohio River.River.

Five Major WatershedsFive Major Watersheds3) 3) Susquehanna/Chesapeake Basin Susquehanna/Chesapeake Basin – largest – largest

watershed in PA covering 46% of the state. The watershed in PA covering 46% of the state. The largest river is the Susquehanna with has its largest river is the Susquehanna with has its headwaters in New York’s Otsego Lake and its headwaters in New York’s Otsego Lake and its mouth at Chesapeake Bay.mouth at Chesapeake Bay.

Major tributaries includeMajor tributaries include::• Lackawanna, Conestoga, West Branch Lackawanna, Conestoga, West Branch

Susquehanna, and Juniata Rivers, Also Loyalsock Susquehanna, and Juniata Rivers, Also Loyalsock and Tuscarora Creeksand Tuscarora Creeks

Five Major WatershedsFive Major Watersheds

4) 4) Potomac Basin Potomac Basin – Does not flow through – Does not flow through Pennsylvania, but a portion of its basin is Pennsylvania, but a portion of its basin is located within the state.located within the state.

PA tributaries includePA tributaries include::• Shenandoah RiverShenandoah River• Marsh, Wills, Tonaloway, Licking, Rock, Marsh, Wills, Tonaloway, Licking, Rock,

Conocochegue, and Antietam CreeksConocochegue, and Antietam Creeks

Five Major WatershedsFive Major Watersheds

5) 5) Delaware Basin Delaware Basin – Pa’s third largest – Pa’s third largest watershedwatershed

Tributaries includeTributaries include::• Lackawanna RiverLackawanna River• Upper, Middle, and Lower Lehigh RiversUpper, Middle, and Lower Lehigh Rivers• Maiden and Brandy Wine CreeksMaiden and Brandy Wine Creeks

Stream BiologyStream Biology

Three dominant groups of organisms in stream Three dominant groups of organisms in stream communities.communities.

1. Algae – and other Protists1. Algae – and other Protists

2. Invertebrates2. Invertebrates

3. Vertebrates3. Vertebrates

Stream BiologyStream Biology

• AlgaeAlgae – producers or autotrophs – producers or autotrophs• Animal-like Protists including:Animal-like Protists including:• Ciliates and paramecia – eat bacteria and algaeCiliates and paramecia – eat bacteria and algae• Amoeba – Protist – engulf their foodAmoeba – Protist – engulf their food• Protists – are called saprotrophs – Protists – are called saprotrophs – feed on feed on

decayed organic matterdecayed organic matter. Some Protists are called . Some Protists are called raptorsraptors because they eat other Protists. because they eat other Protists.

InvertebratesInvertebrates Common typesCommon types::• InsectsInsects – flies and beetles occur in almost every stream – flies and beetles occur in almost every stream

• MollusksMollusks• WormsWorms• The larval stage of flies and beetles live in water. Adult forms live The larval stage of flies and beetles live in water. Adult forms live

on land. on land. • ExceptionException – water strider stays on the surface of the water. – water strider stays on the surface of the water. • Some flies are shredders – eat tissue of other organisms/organic Some flies are shredders – eat tissue of other organisms/organic

matter and wood. Other flies are predators eating their prey matter and wood. Other flies are predators eating their prey whole or piercing its tissue and sucking out the fluid.whole or piercing its tissue and sucking out the fluid.

• MollusksMollusks – feed on algae and plants. Are primary consumers. – feed on algae and plants. Are primary consumers.

VertebratesVertebrates • Amphibians Amphibians – salamanders and frogs – go through various life – salamanders and frogs – go through various life

stages in the stream. stages in the stream. • Frogs – predators – insect eaters – with a sticky tongue Frogs – predators – insect eaters – with a sticky tongue

adaptation adaptation • Salamanders and Newts Salamanders and Newts – insect eaters and their larvae– insect eaters and their larvae• FishFish – are the dominant freshwater vertebrate – are the dominant freshwater vertebrate• GrazersGrazers – algae eating fish – algae eating fish• StrainersStrainers or Suckers depending on how they feed  or Suckers depending on how they feed • Predator fish Predator fish – Pike, Pickeral, Gars, Bullhead– Pike, Pickeral, Gars, Bullhead• Detritivores Detritivores – feed on shredding sediments and filter their – feed on shredding sediments and filter their

food from those sediments.food from those sediments.

Factors That Affect Freshwater Factors That Affect Freshwater EcosystemsEcosystems

Interactions between the biotic and abiotic factors determine the Interactions between the biotic and abiotic factors determine the numbers and kinds of organisms in the fresh water ecosystem.numbers and kinds of organisms in the fresh water ecosystem.

Abiotic factors that affect biodiversityAbiotic factors that affect biodiversity

1 – temperature1 – temperature

2 – current & velocity2 – current & velocity

3 – substrate3 – substrate

4 – stream order4 – stream order

5 – amount of sunlight5 – amount of sunlight

6 – turbidity6 – turbidity

7 – quantities of dissolved substances7 – quantities of dissolved substances

8 – ph8 – ph

9 – organic matter9 – organic matter

Stream OrderStream Order• Streams form over time as runoff flows along tiny Streams form over time as runoff flows along tiny

channels called rills. Rills flow into larger streams and channels called rills. Rills flow into larger streams and eventually into rivers. eventually into rivers.

• The smallest streams are called first order streams with The smallest streams are called first order streams with flow into second order streams which flow into third flow into second order streams which flow into third order streams which flow into fourth order streams and order streams which flow into fourth order streams and so on. so on.

• In Pennsylvania 80% of all streams are first and second In Pennsylvania 80% of all streams are first and second order streams.order streams.

• The size or order of a stream relates directly to the The size or order of a stream relates directly to the organisms that inhabit the ecosystem.organisms that inhabit the ecosystem.

Stream OrderStream Order• 11stst order streams - largest insect populations and order streams - largest insect populations and

little if any fishlittle if any fish• 3rd order streams – are dominated by plants and 3rd order streams – are dominated by plants and

game fishgame fish• Larger streams – contain diverse populations of Larger streams – contain diverse populations of

algae, fish, and other aquatic organisms.algae, fish, and other aquatic organisms.

TemperatureTemperatureTemperature differences are caused by:Temperature differences are caused by:

1 – velocity of the water1 – velocity of the water

2 – depth2 – depth

3 – amount of vegetation near stream banks3 – amount of vegetation near stream banks

4 – seasonal changes – for example snow melt4 – seasonal changes – for example snow melt

5 – natural springs5 – natural springs– Temperature affects the kinds and numbers of species in a Temperature affects the kinds and numbers of species in a

stream. stream. – Carp and catfish can live in a wide range of temperatures.Carp and catfish can live in a wide range of temperatures.– Protists, algae, and trout survive only in certain temperatures.Protists, algae, and trout survive only in certain temperatures.

Current and VelocityCurrent and Velocity• Streams are unidirectional meaning they flow in one direction. Streams are unidirectional meaning they flow in one direction.

– In this way they carry their load as well as nutrients stream organisms need. If they In this way they carry their load as well as nutrients stream organisms need. If they do not “capture” their nutrients quickly, they must wait for the stream to bring do not “capture” their nutrients quickly, they must wait for the stream to bring more. more.

• The flow of water exerts a force on organisms in the stream. The flow of water exerts a force on organisms in the stream. – Mollusks can resist this force. Its muscular foot enables it to attach itself to rocks, Mollusks can resist this force. Its muscular foot enables it to attach itself to rocks,

plants, and the streambed itself. plants, and the streambed itself.

• Some fish are streamlined so they can move with or against the current. Some fish are streamlined so they can move with or against the current. • Keep in mind that the velocity of the stream is an abiotic factor. Keep in mind that the velocity of the stream is an abiotic factor.

– A stream’s velocity changes with its course and its depth. The widening of a river A stream’s velocity changes with its course and its depth. The widening of a river and a smoothing of its bed actually cause an increase in average stream velocity and a smoothing of its bed actually cause an increase in average stream velocity towards its mouth. Stream velocity is lower at the water’s surface and where the towards its mouth. Stream velocity is lower at the water’s surface and where the water meets the stream meets the channel bed. Stream velocity is most rapid in the water meets the stream meets the channel bed. Stream velocity is most rapid in the middle of the water column due to least resistance. middle of the water column due to least resistance.

• Most species of fish are unaffected by the velocity and can live nearly anywhere. Most species of fish are unaffected by the velocity and can live nearly anywhere. Insects are usually restricted to calmer waters.Insects are usually restricted to calmer waters.

SubstrateSubstrate• Substrate is the material that organisms live in, on, or around. It contains Substrate is the material that organisms live in, on, or around. It contains

both organic and inorganic particles. both organic and inorganic particles. • Organic substrate Organic substrate – contains algae and other small particles of matter.– contains algae and other small particles of matter.• Inorganic substrate Inorganic substrate – contains rocks, pebbles, silt, sand, and mud that – contains rocks, pebbles, silt, sand, and mud that

make up the stream channel. make up the stream channel. • Most invertebrates live in or under the rocky substrate. Freshwater Most invertebrates live in or under the rocky substrate. Freshwater

sponges live their lives attached to the tops and sides of rocks. Other sponges live their lives attached to the tops and sides of rocks. Other sponges attach to the sides and bottom of the stream. sponges attach to the sides and bottom of the stream.

• Some organisms live in the substrate. One type of dragonfly larva lives in Some organisms live in the substrate. One type of dragonfly larva lives in the sandy substrate of riverbeds and gathers the oxygen it needs by way the sandy substrate of riverbeds and gathers the oxygen it needs by way of a siphon. of a siphon.

• Bullheads often live deep within gravelly substrates. Bullheads often live deep within gravelly substrates. • In some cases, stream organisms use plants as substrates. Example: midge In some cases, stream organisms use plants as substrates. Example: midge

flies.flies.

SunlightSunlight

• The amount of light a stream receives also The amount of light a stream receives also affects the biodiversity of the stream. affects the biodiversity of the stream.

• Plants rely on photosynthesis to make their Plants rely on photosynthesis to make their energy. An area in a stream that is darker energy. An area in a stream that is darker generally has fewer organisms. generally has fewer organisms.

TurbidityTurbidity• The amount of sunlight that penetrates a body of water The amount of sunlight that penetrates a body of water

depends on the stream’s clarity or turbidity. depends on the stream’s clarity or turbidity. – Turbidity reflects the amount of suspended matter in the Turbidity reflects the amount of suspended matter in the

water. Suspended material in the water includes: silt, clay, water. Suspended material in the water includes: silt, clay, small organisms (plankton), and organic debris.small organisms (plankton), and organic debris.

Factors that affect stream turbidity includesFactors that affect stream turbidity includes::• Increase in erosionIncrease in erosion• Periods of high waterPeriods of high water• Large amounts of melting snowLarge amounts of melting snow• Heavy rainHeavy rain

TemperatureTemperature

• Also affects turbidity.Also affects turbidity.• Cold snowmelt entering the stream carries Cold snowmelt entering the stream carries

large amounts of sediment. large amounts of sediment. • Warm stream waters promote plankton Warm stream waters promote plankton

growth. growth.

Dissolved SaltsDissolved SaltsSome of a streams load is a dissolved load or materials dissolved in the stream’s Some of a streams load is a dissolved load or materials dissolved in the stream’s

water. Some of the dissolved load enters the stream as the water flows into the water. Some of the dissolved load enters the stream as the water flows into the riverbed. Most of the dissolved load enters the stream from groundwater.riverbed. Most of the dissolved load enters the stream from groundwater.

Some of the dissolved load includes:Some of the dissolved load includes:

These elements are essential to the organisms that live in the stream.These elements are essential to the organisms that live in the stream.

Magnesium – plant growthMagnesium – plant growth

Calcium – critical in fish bones and mollusk shellsCalcium – critical in fish bones and mollusk shells

IronIron

SodiumSodium

Potassium – plant growthPotassium – plant growth

SulfurSulfur

Silicon – used by microscopic diatoms to make their shells and by sponges to make Silicon – used by microscopic diatoms to make their shells and by sponges to make their spiculestheir spicules

Nitrogen Nitrogen

Phosphorus – plant growthPhosphorus – plant growth

Dissolved SaltsDissolved Salts

• In excess nitrogen and phosphorus stimulate In excess nitrogen and phosphorus stimulate plant and algae growth. plant and algae growth.

• Excess algal growth is called an algal bloom. Excess algal growth is called an algal bloom. Algal blooms deplete oxygen levels in the Algal blooms deplete oxygen levels in the water and can result in the death of many water and can result in the death of many organismsorganisms.

Dissolved GasesDissolved Gases• Streams contain dissolved oxygen and carbon dioxide. Streams contain dissolved oxygen and carbon dioxide.

• Dissolved oxygen is important in determining the biodiversity of a stream. Dissolved oxygen is important in determining the biodiversity of a stream. • Oxygen enters the water from the air. Oxygen enters the water from the air.

– The amount of oxygen dissolved in the stream depends on the temperature The amount of oxygen dissolved in the stream depends on the temperature of the water. of the water.

• Cooler water holds more dissolved oxygen than does warm water. Cooler water holds more dissolved oxygen than does warm water. • The amount of dissolved oxygen also depends on photosynthesis and The amount of dissolved oxygen also depends on photosynthesis and

respiration.respiration.• Beetles get oxygen directly from the water or use air tubes to get oxygen from Beetles get oxygen directly from the water or use air tubes to get oxygen from

the air. Worms and other invertebrates absorb oxygen through their skins. the air. Worms and other invertebrates absorb oxygen through their skins. • The streams current also affects the oxygen level. Slower stream current The streams current also affects the oxygen level. Slower stream current

means less oxygen is available to organisms in the water. means less oxygen is available to organisms in the water. • Organisms have adapted to compensate for the lower amount of oxygen.Organisms have adapted to compensate for the lower amount of oxygen.

AdaptationsAdaptationsOrganisms have adapted to compensate for a lower amount of Organisms have adapted to compensate for a lower amount of

oxygen.oxygen.

1 – Many organisms can increase the current that flows over their 1 – Many organisms can increase the current that flows over their respiratory structures. respiratory structures.

– Mayflies move their gills back and forth to increase the Mayflies move their gills back and forth to increase the available oxygen.available oxygen.

2 – Some insects have small holes in their shells that enable them to 2 – Some insects have small holes in their shells that enable them to create a current through their bodies when oxygen levels are create a current through their bodies when oxygen levels are low. low.

• The decomposition of organic matter also affects the oxygen The decomposition of organic matter also affects the oxygen content of the water. Oxygen is used up during decomposition. content of the water. Oxygen is used up during decomposition. This process occurs faster in warmer water.This process occurs faster in warmer water.

Carbon DioxideCarbon Dioxide

• Most of the carbon dioxide in stream water Most of the carbon dioxide in stream water comes either from the atmosphere or comes either from the atmosphere or groundwater. groundwater. – Decomposition and respiration are the other two Decomposition and respiration are the other two

sources. Oxygen is used up during decomposition. This sources. Oxygen is used up during decomposition. This process occurs faster in warmer water.process occurs faster in warmer water.

• As plants photosynthesize and organisms absorb As plants photosynthesize and organisms absorb carbonate minerals from the water, carbon carbonate minerals from the water, carbon dioxide is removed from a stream.dioxide is removed from a stream.

Organic MatterOrganic MatterMost organic matter in a stream is used for food. Most organic matter in a stream is used for food.

Organic matter includesOrganic matter includes::• AlgaeAlgae• PlanktonPlankton• Bits of leavesBits of leaves• Decaying woodDecaying wood• Decaying organismsDecaying organisms

Too many nutrients can decrease the oxygen levels. Too few Too many nutrients can decrease the oxygen levels. Too few nutrients cause organisms to begin to travel to other nutrients cause organisms to begin to travel to other parts of the stream in search of food. parts of the stream in search of food.

pHpH• The Ph of a solution is the measure of its concentration The Ph of a solution is the measure of its concentration

of specific hydrogen ions. of specific hydrogen ions. • Ph ranges for 0-14Ph ranges for 0-14• Ph of 7 is neutralPh of 7 is neutral• Ph higher than 7 is a basePh higher than 7 is a base• Ph lower than 7 is an acidPh lower than 7 is an acid• Pure water has a Ph of 7 and is neutral. Pure water has a Ph of 7 and is neutral. • Most rain water is slightly acidic. Most rain water is slightly acidic. • Most stream organisms can tolerate small changes in ph. Most stream organisms can tolerate small changes in ph.

However, if a stream becomes acidic populations of However, if a stream becomes acidic populations of organism will become reduced. organism will become reduced.

PA pH BalancePA pH BalanceShort term acidic effects include Short term acidic effects include fish killsfish kills and and decreases in insect decreases in insect

populationspopulations. .

Acid mine drainage results in the deaths of many bottom dwelling Acid mine drainage results in the deaths of many bottom dwelling organisms. organisms.

Acid mine drainage is not only acidic, but contains heavy metals and other Acid mine drainage is not only acidic, but contains heavy metals and other pollutants. These substances settle to the bottom of the stream channel pollutants. These substances settle to the bottom of the stream channel and becomes trapped in the sediments. These substances enter and becomes trapped in the sediments. These substances enter organisms through the process of diffusion. organisms through the process of diffusion.

Pennsylvania’s streams are susceptible to acidification for three reasonsPennsylvania’s streams are susceptible to acidification for three reasons::

1 – Pennsylvania receives some of the most acidic rainfall in the U.S.1 – Pennsylvania receives some of the most acidic rainfall in the U.S.

2 – Rocks in Pennsylvania contain minerals that contribute to acidification.2 – Rocks in Pennsylvania contain minerals that contribute to acidification.

3 – Pennsylvania has many coalmines.3 – Pennsylvania has many coalmines.

• Fortunately many streams buffer or prevent large changes in Ph.Fortunately many streams buffer or prevent large changes in Ph.