1. Kyle McCanney Adam Baumann
NY Lake Comparison
Kyle McCanney
Adam Baumann

2. Phosphorus Many forms of phosphorus We are concerned with SRP
Different techniques for each type
We are concerned with SRP
Soluble Reactive Phosphorus
Biologically available phosphorus
Nutrient uptake

3. Why Phosphorus? ATP and ADP Limiting Nutrient
Energy currency of the cell
Limiting Nutrient
Redfield ratio
Most limiting nutrient
Far less is available than what is needed
Indicator of trophic state of lake

4. SRP Measurement React the lake samples with a combined reagent
Form a phospho-antimony-molybdate complex (in acidic medium)
Further reduced by ascorbic acid to form a blue colored complex
Absorbs light around 880nm

5. Quantification of SRP Make known standard solutions of phosphate
Cover range of phosphate concentrations expected
Measure absorbance's at 880nm
Treated same as samples will be
Plot absorbance vs. concentration
To be used to quantify unknown samples

6. MAGIC MAGnesium Induced Coprecipitation Addition of NaOH to samples
Precipitates Brucite [Mg(OH)2], pulling soluble P with it
Samples are centrifuged and precipitate is acidified
Allows for lower detection limit
Freshwater samples?

8. Arbutus and Rich Diel Vertical Migration of Zooplankton
Proximate cause = light
Ultimate cause = avoid predation
We sampled during the day
Most zooplankton found below irradiance level
corresponds to lower nutrient levels at these depths

9. Green Green lakes phosphorus data looks unique
However, most zooplankton found at concentration consistent with Rich and Arbutus
Also below level of irradiance

10. Measurements and Errors
Nitrogen levels
Compare nutrient information
Error
Too many people sampling too many different parameters
First time technique users