2.1 - Monitoring Water Quality Flashcards
Define:
Monitoring
Keeping track of something for a specific purpose
Is clarity a good indicator of water quality?
Clarity is not a good indicator of water quality. CLear water can be harmful, such as a lake affected by acid rain.
How does the government determine water quality?
The government determines water quality based on what the water is used for:
- Human drinking water
- Recreation
- Livestock drinking water
- Irrigation
- Protection of aquatic life
How are organisms living in the water of use to scientists?
Scientists can use organisms living in the water to help determine it’s quality
What is an example of a microscopic organism (bacteria) that can cause illness if they are present in large numbers?
Microscopic organisms (bacteria) can cause illness if they are present in large numbers Ex. E. coli
What are aquatic invertebrates? (Provide examples)
Have no backbone. Include: crustaceans, insects, worms and mollusks
How can the presence or absence of aquatic invertebrates indicate water quality?
Because these organisms require certain living conditions to survive, their presence or absence can be used as an indicator of water quality.
- Ex. Insects thrive in water high in dissolved in O2
- Ex. Worms thrive in polluted water (low dissolved O2)
______ in water decreases as ______ increases and as _________ decreases
Diversity in water decreases as acidity increases and as dissolved O2 decreases
True or false: Water in the environment contains very few different compounds. The most commonly monitored are: - Dissolved Oxygen - Nitrogen and Phosphorous - Acidity - Pesticides - Toxins - Heavy Metals
False. Water in the environment contains many different compounds. The following are most commonly monitored:
- Dissolved Oxygen
- Nitrogen and Phosphorous
- Acidity
- Pesticides
- Toxins
- Heavy Metals
Dissolved oxygen is a chemical indicator that is commonly monitored. Describe its importance.
It varies, but most organisms need 5 mg/L (5ppm) of dissolved O2 to survive.
Dissolved O2 depends on:
- Temperature
- Turbulence (more water movement =. More dissolved O2)
- Amount of photosynthesis
- Number of organisms using up O2
Nitrogen and Phosphorous are chemical indicators that are commonly monitored. Describe its importance.
- Sewage outfalls (runoff pipes from factories and industry) and fertilizer runoff can add nitrogen and phosphorus to water systems
- Too much nitrogen and phosphorus in the water can reduce dissolved O2
- Higher concentrations of these nutrients leads to increase growth of algae and plants (algal bloom)
- As the plant matter dies, the bacteria that decompose it increase, using up dissolved O2
- As O2 levels decrease, fish and insects die
Acidity is a chemical indicator that is commonly monitored. Describe its importance.
- Normal precipitation has a pH of 5.6, because CO2 from the air dissolves into form weak carbonic acid.
- Acid rain or snow has a pH lower than 5.6
- When it falls on water systems, it lowers their pH. - Most fish die if the water’s pH drops to 4.5
- In places where the soil and water lack natural bases to help neutralize the acid, the forests and lakes suffer damage
- Ex. Canadian Shield
- Spring acid shock occurs when acidic snow and ice melt in the spring, dramatically lowering the pH of water in a short amount of time.
- Harmful to eggs and young fish
Pesticides are chemical indicators that are commonly monitored. Describe their importance
- Most modern pesticides are designed to break down in the soil within one season. However, they can last longer in the tissues of some organisms.
- Sometimes, insect populations become pesticide-resistant and then new pesticides have to be used.
- Several pesticides mixed together can have a cumulative effect and become very toxic (poisonous)
Toxins are chemical indicators that are commonly monitored. Describe their importance.
Toxins - Substances that cause serious health problems or death when introduced into an organism
LD50
- Used to measure toxins
- The amount of a substance that causes 50% of test animals to die (LD stands for lethal dose)
- States as amount given per unit of body mass
- The lower the number, the more toxic
Heavy metals are chemical indicators that are commonly monitored. Describe their importance.
- Have a density of 5g/cm3 or more
- Ex. Copper, lead, zinc, mercury, cadmium, nickel
- Heavy metals occur naturally, but are also processed into products used by humans. If they enter the water supply, they can accumulate in the food chain.
- Heavy metals are especially toxic to children, as they can affect development and cause brain damage or even death
