What is Water Quality?

• the chemical, biological and physical status of a body of water

• how healthy the water is?

• lakes & ponds

• rivers & streams

• oceans

How do we measure whether water is HEALTHY or not?

• Temperature

• Turbidity

• pH

• Dissolved Oxygen

• Nitrates

• Phosphates

• Bioindicators

TEMPERATURE

HEALTHY WATER: 32^oF - 97^oF

UNHEALTHY WATER: below 32 degrees/above 97 degrees



TEMPERATURE

• Coral bleaching: the whitening of coral due to stress in the environment (like an increase in water temperature or UV radiation)

TEMPERATURE

• As water temperature increases , the amount of dissolved oxygen decreases

TURBIDITY

is a measure of how cloudy water is

What can cause TURBIDITY to INCREASE?

• plant plankton (phytoplankton) INCREASES - ALGAL BLOOM

• INCREASE in SEDIMENT or DIRT

• INCREASE in ANIMAL WASTE

When TURBIDITY is HIGH

• WATER will ABSORB MORE HEAT

• TEMPERATURE will INCREASE

• WARM water holds LESS OXYGEN

  
  

  so, HIGH TURBIDITY = LOW OXYGEN

  
  

pH

is the acidity of water

DISSOLVED OXYGEN

D.O.

the amount of oxygen water holds.

ON TEST

2 sources of Oxygen in water:

Atmosphere and plants in water

COOLER water

holds MORE D.O.

Algal Bloom

the decay process (when the algae die) uses a large amount of oxygen and can drop the DO levels to dangerously low amounts

CHANGES D.O. LEVELS

• TEMPERATURE change

• How DEEP the water is

• How many PLANTS are in water

NITRATES

are nitrogen-containing compounds used for plant growth (fertilizers)

NITRATE levels CHANGES

• When nitrates are added

  --- fertilizers

  --- animal waste

  
  

• Can cause algae to grow at rapid rates leading to algal blooms

PHOSPHATES

naturally occurring chemical compounds which contain phosphorus and oxygen

PHOSPHATE levels CHANGE

• When phosphates are added

  --- detergents

  --- cleaners

  --- animal waste

  
  

BIOINDICATORS

are organisms that live in water that are sensitive to pollution

are used to used to determine the health of an ecosystem

ON TEST

Few macrobiotics in water means that the water is not healthy

Number of BIOINDICATORS CHANGE

When bad things happen

--- TURBIDITY INCREASES

--- D.O. DECREASES

--- TEMPERATURE IS TOO HIGH or LOW

or changes too much

--- pH changes

--- POLLUTION IS PRESENT