pH TURBIDITY Water Quality Factors TEMPERATURE DISSOLVED OXYGEN (DO) PHOSPHATES BIO- INDICATORS pH NITROGEN

TEMPERATURE EFFECTS: changes rate of photosynthesis changes rate of respiration changes DO in water cold water holds more DO hot water holds less DO changes sensitivity of organisms to toxic waste, parasites, disease.

TEMPERATURE Thermal pollution = adding warm water to cold water. CAUSES OF THERMAL POLLUTION: Industry (nuclear power plants, paper mills) Urban Development (storm water runoff, construction, soil erosion)

DISSOLVED OXYGEN (DO) ORANGE = Oxygen MICKEY MOUSE = Water Less Oxygen = Less fish Fish need Oxygen

DISSOLVED OXYGEN (DO) TO INCREASE DO: Much of DO comes from atmosphere Some of DO comes from photosynthesis TO DECREASE DO: Add pollution Add organic waste

ORGANIC WASTE = LOW DO Organic waste = parts of once living things EXAMPLES OF ORGANIC WASTE: Sewage Farm runoff Discharge from food processing plants

HOW RAW SEWAGE LOWERS DO RAW SEWAGE GOES INTO WATER: Decomposers chow down Decomposers take up oxygen Decomposers reproduce, taking up more oxygen No more oxygen for other animals Nothing left but decomposer & sewage-filled water.

HEALTHY POND

RAW SEWAGE IS DUMPED

UNHEALTHY POND

pH pH = measure of concentration of hydrogen ions in a substance Tells whether substance is: ACID BASE NEUTRAL

pH Measured on scale from 0 to 14 0 = highly acidic (HCl) 7 = neutral (pure water) 14 = highly basic (bleach) Seawater pH ranges from 7.5 – 8.5 Average pH of ocean water = 7.8 pH of natural water = 6.5 – 8.5 Optimal range for life = 6.5 – 8.2

pH US Northeastern rain pH = 4.3 Rain elsewhere in US pH = 5.0 – 5.6

pH

pH SOURCES OF LOW pH IN WATER: Acid rain is cause of acid in thousands of lakes Burning fossil fuels has increased acid rain EFFECTS OF LOW pH IN WATER: Low pH directly kills fish pH < 5, most fish eggs die

NITROGEN Living organisms need nitrogen to make proteins Nitrates (NO3) & Nitrites (NO2) are compounds made of nitrogen & oxygen Some nitrogen in water is good The wrong amount is bad

NITROGEN SOURCES OF NITROGEN IN WATER: Human & animal waste fertilizer EFFECTS OF TOO MUCH NITROGEN: Lowers dissolved oxygen (DO).

NITROGEN – EUTROPHICATION Q: How does Nitrogen reduce the amount of DO? A: Eutrophication Nitrogen feeds algae (green stuff) Algae grows & grows Algae blocks sunlight Underwater plants die Algae die and decompose The decomposition takes up oxygen No DO for organisms, so they die

NITROGEN OUR HAPPY POND IS NOW “DEAD”

EUTROPHICATION

NITRATES

PHOSPHATES Phosphorus is an element like hydrogen or oxygen Phosphorus combines with other things to make phosphates Essential for living things Usually present in very small amounts Too much is bad

PHOSPHATES SOURCES OF PHOSPHATES IN WATER: Storm sewer runoff Soil erosion Fertilizer Forest fires Volcanic eruptions

PHOSPHATES

PHOSPHATES EFFECTS OF PHOSPHATES: Eutrophication (same as with nitrates)

PHOSPHATES OUR HAPPY POND IS NOW “DEAD”

EUTROPHICATION

PHOSPHATES

TURBIDITY Measures clearness of water Murky water = greater turbidity Caused by solids blocking sunlight Measured using a Secchi disk or turbidity meter

TURBIDITY

TURBIDITY SOURCES: Human dumping Construction Soil erosion Nitrate pollution Phosphate pollution HUMAN DUMPING: Clay Silt Industrial waste Raw sewage

TURBIDITY EFFECTS: Clogs fish gills Smothers eggs Makes water unlivable

BIO-INDICATORS Bio-indicators = organisms that help determine health of water. Presence or absence tells something about the water. Not always an accurate way to measure water quality. Accurate in telling environmental stress

BIO-INDICATORS HOW HUMANS AFFECT BIO-INDICATORS: Over-fishing Industrial pollution Poor farming practices Adding foreign species

BIO-INDICATORS

BIO-INDICATORS