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47 Cards in this Set

  • Front
  • Back
[ dissolved oxygen in H20 ] range from
0 - 18 ppm
The higher the amount of dissolved oxygen, _________
the more diverse the species of plants and animals
The cooler the water, ______
the more oxygen it can hold
percent saturation
amount of oxygen that can be dissolved in water at any particular temp
Total saturation
under unpolluted conditions, the water is holding as much oxygen as it can
Super-saturation typically occurs in _______
areas of high turbulence
Whitewater rapids indicate _______
water is oxygenating
Oxygen levels in ________ are more constant than _____/_______ because _______
Oxygen levels in streams are more constant than lakes/ponds because oxygen enters lakes/ponds during the day (photosynthesis) while oxygen mixes into streams day and night as water travels over rocks
Diurnal variation
dissolved oxygen [ ]s in ponds/rivers with large populations of aquatic plants fluctuate dramatically from day to night (at night, plants use O2 in respiration and produce O2 in the day through photosynthesis)
Dissolved O2 is depleted when ____ and ____ are abundant.
bacteria and algae (they consume O2 when decomposing organic material)
living index of water quality
organisms provide this because each one has its own threshold dissolved O2 level below which it cannot survive
Organisms are sensitive to dissolved O2 levels, especially (3) ______
young fish
fish eggs
One unit change in pH represents a ______ change in acidity
ten fold
pH of unpolluted precipitation
acid deposition
acid rain
soil that contains ____ can neutralize acid rain
extremes in pH
above 8.5

below 6.5
effects of extreme pH on aquatic life (name 4)
-bones of fish become soft
-females unable to lay eggs
-gills clogged w. mucus
-shells of snails dissolve
alkalinity predicts
BUFFERing capacity of H2O
As alkalinity increases, ________ increases
Hardness indicates
soluble Ca2+, Mg2+, Fe content
Hardness does NOT directly affect these 2 things

____ water tends to be more biologically productive because _____
hard water; because ions that cause hardness are used in plant metabolism
T or F

Hardness is the best criterion for determining water quality

Alkalinity is a better criterion than hardness.
Bacteria turns ammonia into
nitrate (NO3-)
Unpolluted water has a nitrate concentration of
< 1 ppm
nonpoint source pollution
organic pollutants (ie: sewage, manure) with high levels of nitrate whose sources are difficult to "pinpoint"
_____% of nitrates that enter the nation's waterways come from nonpoint source pollution
Nitrate levels greater than ___ ppm can damage aquatic organisms in a healthy lake or stream.
10 ppm
massive growth of algae and other plants due to excess nitrates
Bloom causes water to (2)
-become murky

-raise its temp
Phosphates originate from (4)
-by-product of potato processing
-cattle feedlot runoff
-human sewage
____% of phosphates entering the nation's surface H2O are from nonpoint sources
Clean water should contain _____ ppm of phosphate
< 0.1 ppm

phosphate and point-one both start with P!
Total phosphorous tests are the best test to use because _______
they measure organic and inorganic phosphorous
Salty runoff's negative effects (3)
-kills roadside/aquatic vegetation
-damage fish fry and eggs in lakes
-creates chemical barrier preventing O2 from reaching deeper waters
Unpolluted water has chloride levels of ___ to ____ ppm.
8 - 12 ppm
Water with ____ ppm of chlorine is considered undrinkable.
250 ppm
Aquatic organisms that are sensitive to dissolved O2 and CO2 are more likely to be found in unpolluted ______ than in ______.
Streams; ponds
cloudiness in water caused by suspended solid matter that scatters light passing through the water
Turbidity caused by (3)
-sediment from disturbed/eroded soil
-microscopic plankton
-high pop of bottom-feeding fish like carp
Effects of turbidity (5)
-block out light needed for photosynthesis
-bury eggs of fish
-smother benthic creatures
-carry nutrients and pesticides throughout water system
-absorb heat from sunlight and raise surface water temp (dec. amt. of O2)
bottom dwelling
Higher temp. cause
metabolism to inc. creating greater O2 demand
warm weather: water at bottom is _____ than water at surface
cold weather: water at bottom is _____ than water at surface
temperature effects (5)
-egg incubation