Stream Ecology

Steam Flow Straight paths Parallel to bed Water moves In tiny circles Little mixing Of water Much mixing Of water

Velocity ______________: Distance water flows during a period of time (m/sec) Determines the type of flow Slow moving  ________________ flow Swift moving  ________________ flow Also determines the _____________ which the water will carry.

Sediment Load Sediment movement ______________________: Sediment carried in solution Dissolved minerals ______________________: Suspension Silt and clay Most sediment are suspended ___________________: Sediment carried on the bottom Sand Gravel Pebbles

River Deposits Sediment drop as a river or stream slow down. __________: Deposits formed when a stream slows down around a bend. Made of sand and gravel _____________________: Part of a river valley covered during a flood. Very fertile areas

Factors that Affect Freshwater Ecosystems _____________________: Non-living factors ________________________

Temperature Small changes in water ______________ can directly or indirectly affect the flora (plants) and fauna (animals) in a stream. Must measure at different locations along the stream in order to indicate a source of ___________________. Sources of thermal pollution ______________________ (Power plants) Runoff from __________________________

Temperature Factors Affecting Water Temperature ________________________________ ______________________ _________________________ (Other streams entering)

Temperature Temperature affects Amount of ___________________________ in the water ___________________ water holds more DO _____________ and ___________ prefer colder water because they require more DO _____________________ water holds less DO The rate of __________________ increases as the temperature of the water goes up. ______________________ The _______________ the water, the greater the conductivity We will use ________ as our unit of temperature

Current & Velocity ________________ are carried in the current and must be used quickly or they will be lost to the organism. Organisms must have adaptations to help them live in the current _____________________

Current & Velocity ________________: Change in distance over time. Velocity changes with the steams course and depth. Factors Affecting Stream Velocity _______________ ___________________________________

Current & Velocity Affect on organisms __________  Little effect __________  Limited to calm water

Substrate ______________: Material organisms live in, on, or around. Stream substrates _____________  Algae, small pieces of dead organisms _____________  Rocks, pebbles, sand, silt, mud

Substrate _________________ Most are ____________ living On the surface of rocks In the sandy river/stream beds ________________ may serve as a substrate for insect larva

Sunlight More light  more ___________________

Turbidity _______________: Water clarity Suspended matter includes: A measure of the amount of _______________________ in the water. Suspended matter includes: ______________

Turbidity Sources of turbidity Effects of turbidity ____________________ Effects of turbidity Reduces water ______________ Decreases __________________ Increases ___________________

Dissolved solids Most enter steams and rivers from groundwater Examples of dissolved solids ____: Plant nutrient ____: Needed in fish bones/mollusks shells ____ ____: Plant nutrient (> 0.03 ppm adds to plant growth) ____: Needed by diatoms and sponges for shells ____: Plant nutrient (Unpolluted water < 4 ppm)

Conductivity ____________________ is the measure of the ability of water to allow electricity to pass through it. Conductivity ______________ with the presence of _________________ dissolved solids like: _______________ The conductivity of a stream is affected by the ___________ of the ground through which the stream flow ______________ Low conductivity ______________ Higher conductivity

Conductivity Conductivity is measured in units called _____________________________________. Distilled water- _____________ Rivers in U.S. _______________ Healthy streams _____________

Dissolved Oxygen ________________________ is a measure of the concentration of oxygen gas dissolved in the water. Dissolved oxygen can enter water by ______________________________. ______________________________ _______________________________ Dissolved oxygen can be removed from water by _________________________________

Dissolved Oxygen Factors affecting DO _______________________ The ______ the temperature, the _____ DO the water can hold _________________ The _________ the salinity, the ______ DO in the water The _______ the salinity, the ___________ the DO in the water __________________ As atmospheric pressure _______________ the amount of DO ______________ As atmospheric pressure ______________ the amount of DO ________________

Dissolved Oxygen Units of measure for DO DO Levels and Aquatic Life _________________: Percentage of DO that will dissolve in a sample of water at a given temperature. _______________: Amount of oxygen dissolved in water DO Levels and Aquatic Life ____ mg/L: not enough oxygen to support life. ____ mg/L: only a few fish and aquatic insects can survive. _____ mg/L: good for many aquatic animals, low for cold water fish _____ mg/L: very good for most stream fish

Dissolved Oxygen ______________________________: Measure of the quantity of DO used by bacteria during decomposition.

pH ____: A measure of how acidic or basic the water is. pH is the concentration of _____________in a sample. Scale from ____________ 1-6 ______________ 7 _______________ 8-14 _____________ Optimum pH for aquatic organisms ranges between ___________

pH Factors affecting pH _____________________________ ______________________________ During the day, _________________ removes ____ thereby making the water more __________________ During the night, __________ levels ______________ and pH becomes more _________________ ___________________ (carbonic acid, nitric acid, sulfuric acid)

pH 3 Factors Hurting the pH of PA streams PA receives high amount of _________________ ______________ in PA add to the acidity of water ______________ is abundant

Nutrients ________________ are essential for the proper functioning of a stream ecosystem. Excess nutrients, however, can lead to problems. Nutrients found in an aquatic ecosystem ________________: Excessive amounts can lead to eutrophication ________________

Nutrients Factors Affecting Nutrient Levels: ______________________

Nutrients Acceptable Levels of Nutrients ___________________: Less than 1 mg/L ___________________: Less than 0.05 mg/L ___________________: Average 30 mg/L

Benthic Macroinvertebrates _________________________: Large aquatic invertebrates that live on the bottom of a stream or river. Often _________________________ Certain species are indicators of “___________________” Other species are indicators of “____________________”

Algae & Animal-like Protists _________________: Plant-like protists _______________- Producers capable of photosynthesis Base of most aquatic food chains

Algae & Animal-like Protists Classification of Protists _______________________: Protists that feed on decayed organic material _______________________: Protists that eat other protists.

Zooplankton

Invertebrates _______________: Flies, beetles, water striders ______________ of many insects are aquatic Adults may move on land _______________: Freshwater clams, snails _______________: Aquatic worms, nematodes

Vertebrates ________________: Require water in order to reproduce. Salamanders Frogs ________________

Invertebrates: A Closer Look 3 Classes of Aquatic Macroinvertebrates _______________ Organisms: Pollution-intolerant Indicates GOOD WATER QUALITY _______________ Organisms: Somewhat tolerant to water pollution Indicates AVERAGE WATER QUALITY, SLIGHTLY POLLUTED _______________ Organisms: Pollution-tolerant Indicates POOR WATER QUALITY

Invertebrates: A Closer Look CLASS I Organisms: Stonefly nymph Caddisfly larva Water penny Riffle beetle Mayfly nymph Dobsonfly nymph “Hellgrammite”

Invertebrates: A Closer Look Class II Organisms Beetle larva Sowbug Damselfly nymph Dragonfly nymph Cranefly larva Clams Crayfish Scud

Invertebrates: A Closer Look Class III Organisms Midge fly larva Snails Leech Aquatic worms