temperature dissolved oxygen (do) oxygen (do) ph nitrogen phosphates turbidity bio- indicators water...

TEMPERATURETEMPERATURE

DISSOLVEDDISSOLVEDOXYGEN (DO)OXYGEN (DO)

pHpH NITROGENNITROGEN

PHOSPHATESPHOSPHATES

TURBIDITYTURBIDITY

BIO-BIO-INDICATORSINDICATORS

Water Quality FactorsWater Quality Factors

TEMPERATURE

EFFECTS:changes rate of photosynthesischanges rate of respirationchanges DO in water

cold water holds more DOhot 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

MICKEYMOUSE = Water

Fish needOxygen

Less Oxygen =Less fish

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:

1. Decomposers chow down

2. Decomposers take up oxygen

3. Decomposers reproduce, taking up more oxygen

4. No more oxygen for other animals

5. 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 140 = highly acidic (HCl)7 = neutral (pure water)14 = highly basic (bleach)

Seawater pH ranges from 7.5 – 8.5Average pH of ocean water = 7.8pH of natural water = 6.5 – 8.5Optimal range for life = 6.5 – 8.2

pH

US Northeastern rain pH = 4.3

Rain elsewhere in US pH = 5.0 – 5.6

pH

pHSOURCES 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

NITROGENNITROGEN

OUR HAPPY POND IS OUR HAPPY POND IS NOW “DEAD”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)

PHOSPHATESPHOSPHATES

OUR HAPPY POND IS OUR HAPPY POND IS NOW “DEAD”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

HUMAN DUMPING:

Clay

Silt

Industrial waste

Raw sewage

SOURCES:

Human dumping

Construction

Soil erosion

Nitrate pollution

Phosphate pollution

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