1. Chemicals are recycled between organic matter and abiotic reservoirs
Chemicals are recycled between organic matter and abiotic reservoirs
Nutrients recycle between
Organisms and abiotic reservoirs
4 basic steps in cycling 3
Consumers 2
Producers 1
Detritivores
Nutrients
available
to producers 4
Figure 37.15
Abiotic reservoir

2. Biochemical Cycles Involve both abiotic and biotic components
Can be local or global cycles
Soil is main reservoir in local cycles (Phosphorus)
Air or Gases are reservoirs in global cycles (Carbon, Nitrogen & Water)

3. Water moves through the biosphere in a global cycle
Transport over land
Solar energy
Net movement of water vapor by wind
Runoff and
groundwater
Percolation
through soil
Precipitation over land
Evaporation and
transpiration from
land
Precipitation
over ocean
Figure 37.16
Evaporation from ocean
Water moves through the biosphere in a global cycle
Solar heat
Drives the global water cycle of precipitation, evaporation, and transpiration

4. What does the level of the chemicals we’re testing tell us about the Chaska Creek?
We will test:
Ammonia
Dissolved Oxygen
Carbon Dioxide pH
Nitrates
Phosphates
Total Hardness

5. The carbon cycle depends on photosynthesis and respiration
The carbon cycle depends on photosynthesis and respiration
Carbon is taken from the atmosphere (CO2)by photosynthesis
Used to make organic molecules, and returned to the atmosphere by cellular respiration
Carbon compounds in animal waste, plant litter & dead organism is consumed by detritivores and they return the carbon via cellular respiration.
CO2 in atmosphere
Photosynthesis
Cellular
respiration
Burning of fossil fuels and wood
Carbon compounds in water
Detritus
Primary
consumers
Higher-level
Decomposition
Figure 37.17

6. Why measure Dissolved Oxygen?
O2 is essential to life
Sources are photosynthesis and air (surface current)
The higher the stream flow the more dissolved oxygen
Depleted by
Decomposition of dead organisms and waste
Respiration of plants and animals
Lower the temperature the more O2 water can hold.
Warm water fish need 02 levels of 4 ppm (parts per million)
Cold water fish (trout, walleye) need 02 levels of 5 ppm

7. Why measure Carbon Dioxide (CO2)?
CO2 is needed for photosynthesis
Co2 is harmful in high concentrations.
Fish must get ride of CO2 and take in O2
Very hard to do is CO2 is in high concentrations
CO2 is 200 times more soluble in water as O2
Normally less than 10 ppm in streams

8. Why measure pH?
pH is a measure of acidity (7 is neutral, 1 is the most acidic and 14 is the least acidic “basic”)
Problems occur if more acidic than 5 and more “basic” than 8.5)
CO2 from cellular respiration and decomposition lowers pH, so polluted water is typically more acidic (because of higher rate of decomposition)
You may need to use it determining ammonia levels. (we’ll talk about this later)

9. The nitrogen cycle relies heavily on bacteria
The nitrogen cycle relies heavily on bacteria
Various bacteria in soil
Convert gaseous N2 to compounds that plants use: ammonium (NH4+) and nitrate (NO3–)
Detritivores
Decompose organic matter and recycle nitrogen to plants
An ingredient of proteins & nucleic acids = important to organisms
Atmosphere is 80% Nitrogen, making it a large reservoir
Nitrogen in atmosphere (N2)
Nitrogen fixation
Nitrogen-fixing
bacteria in root
nodules of legumes
Detritivores
Decomposition
Ammonium (NH4+)
Nitrates
(NO3–)
Assimilation
by plants
Denitrifying
bacteria
soil bacteria
Nitrifying
Figure 37.18

10. Why measure Nitrates? Nitrates are essential for plant growth
High levels are signs of pollution from fertilizer or sewage
Too much nitrate = algal blooms = decrease in oxygen levels
Nitrate is a limiting factor on plant growth
Decreases oxygen because oxygen is used up in the process of decaying all the algal growth and cellular respiration of animals
Good levels would be under 1 mg/L
High levels can cause “Blue Babies” – umbilical cord around neck

11. Why measure Ammonia?
Ammonia is a major metabolic waste produce from fish
Important to test because even small amount can cause stress to fish and damage their gills
Two types in water:
Total Ammonia (NH4+) – Ionized Ammonia
Unionized Ammonia (NH3) – this is toxic to fish
Temperature and pH effect how much of this is present
Sources of ammonia in waters include:
runoff of animal wastes
fertilizers from farm land
the discharge of sewage effluents
dairy shed effluents
food-processing wastes such as those from freezing works.

12. Ammonia Continued…
Test kit will measure Total Ammonia (Ionized Ammonia)
Ammonia levels should be at ZERO
If not at zero we have to use temperature and pH to calculate the Unionized Ammonia levels using this chart…

13. Total Ammonia (level from kit) x multiplication factor (from table) = Unionized Ammonia Level
Levels higher than .05 mg/l = fish being damaged
Levels 2.0 mg/l or higher = fish will die

14. How to manage an Ammonia Problem
Add phosphorus to the water
Will increase plant growth
Plants will recycle the ammonia in the water
This should only be done in small amount, because of the risk of creating an algae bloom

15. The phosphorus cycle depends on the weathering of rock (rock & soil is the reservoir)
Phosphorus and other soil minerals
Are recycled locally
In soil they are inorganic
Plant convert them into organic compounds for consumers to eat
Phosphorus is an ingredient of nucleic acids, phospholipids, and ATP.
It is a mineral component of teeth & bone.
Weathering
of rocks
Geologic
uplift
Runoff
Sedimentation
Leaching
Soil
Plant uptake
of PO43–
Consumption
Decomposition
Rain
Plants
Figure 37.19

16. Why measure Phosphates?
Enters waterways from
waste
Detergents
Poorly treated sewage
Disturbed soil (construction sites)
Usually less than .1 ppm (part per million)
Algae and plants take in phosphates easily so its hard to detect the source
Can cause algal blooms and eutrophication (Death of a Lake)

17. Why measure Total Hardness?
It’s a measure of calcium and magnesium
Source is rock and soil
0-50ppm = soft water
50 – 100 ppm = moderately hard
200 + = very hard water
Algae prefer hard water
Fish are stimulated to spawn when water softens after a heavy rain or melting snow!