science unit c topic 2 Flashcards
What are the two biological indicators and examples of each?
Microbiological indicators ex bacteria such as escherichia coli
aquatic indicators ex shrimp, worms, mollusks, clam
- Lots of organims=?
- Less organisms=?
- low Ph=?
- Lots of worms=?
1.healthier water condition and lots of 02
2.may be condition problems
3.no fish(as pH decreases so do the amount of all
organisms)
4.lower 02 levels
why is dissolved 02 good?
essential for the life of aquatic organisms because they all need oxygen
four factors that affect the amount of 02?
water temp~as temp gets warmer 02 levels go down
turbulence due to wind or speed of moving water~ faster flow to increase oxygen
amount of photosynthesis~more photosynthesis more oxygen
number of organims~more organisms more oxygen required
levels of oxygen
less than 2ppm is no life 2 ppm~worms 4 ppm~more organisms 6 ppm~more organisms 8 ppm~ healthy lots, lots of fish
whats ppm
a small unit of a chemical
problems with phosphorus and nitrogen?
and sources?
helpful but not it too big of quantities
sources are sewage runoff or fertilizer runoff
normal pH of snow and rain
5.6
what Ph to fish start to die?
4.5
Why does the pH of lakes decrease?
Acid runoffs, acidic precipitation, acid rain+acidic snow melting into lakes
what are some soil effects on the aquatic system?
soil+water don’t have enough base to neutralize acidic snow or acidic rain
what is spring acid shock?
acidic snow builds up in winter and melts in spring. lots of acidic water with low pH runs into lakes at one time shocking the system
Pesticides and water?
harmful when not getting broken down in the environment
how to organisms respond to pesticides?
develop resistance because they reproduce so fast
How do pesticides affect aquatic environments?
very toxic in water even in small amounts
what are toxins?
the poison that produces serious health problems or death
Whats LD50 used for? and what does Ld and 50 mean?
to compare toxins? LD=lethal dose 50=50%
What does Ld50 do?
amount of substance given to organisms that kills 50% of the population at a specific dosage
Will all organisms die at the same LD50%
No, all organisms will have different tolerances
As LD50 increases, what does toxicity levels do?
They decrease
What are heavy metals? examples?
five or more times heavier than an equal volume of water examples are copper, lead, mercury, cadmium, zinc, nickel
where are heavy metals found?
natural~rocks, soil, water made~batteries, pipes, fertilizers
how do heavy metal get into the water
leach in fertilizers or pipes
Sulfur dioxide name
SO2
How does sulfur dioxide form?
oxygen combines with sulfur