reu 2013 incubation project
DESCRIPTION
The Effects of Nutrient Deposition on Alpine Lakes. REU 2013 Incubation Project. Katie Husk Advisor: Dr. Diane McKnight. Presentation: Katie Husk Diane McKnight, Katherina Hell, Rylee Archuleta 2013 Environmental REU. Outline. Introduction Site Description Project Overview Methods - PowerPoint PPT PresentationTRANSCRIPT
REU 2013 Incubation ProjectKatie HuskAdvisor: Dr. Diane McKnight
The Effects of Nutrient Deposition on Alpine Lakes
Presentation: Katie Husk
Diane McKnight, Katherina Hell, Rylee Archuleta2013 Environmental REU
Outline•Introduction•Site Description•Project Overview•Methods•Project
Shortcomings•Results•Future
Considerations
Background•Alpine lakes are important indicators of
climate change▫Harsh conditions ▫Small changes in atmospheric composition
result in drastic changes in algae types/quantities
▫Ice out timing/lake temperature▫Nutrient deposition from snowmelt
Green Lake 4• Alpine lake- el 11,700ft• Oligotrophic• Part of Boulder Watershed• 4 mi East of Continental
Divide• West of large metropolitan
area– Denver, Fort Collins, Colorado Springs
• Part of NWT-LTER since 1951
• Studied by INSTAAR since 2000
Regular Sampling- Every Week by INSTAAR• Samples
▫ DOC▫ DOM▫ Nutrients▫ Phytoplankton▫ Chlorophyll a
• Measurements▫ pH▫ Conductivity▫ Light▫ DO▫ Temperature▫ Secchi Depth
• Locations▫ Inlet of Lake▫ Outlet of Lake▫ Surface▫ 3m▫ 9m
My Project• Incubate phosphorus
enriched carboys at 2m to test the effects of nutrient deposition on alpine lakes
• Hypothesis: Increased phosphorus deposition will accelerate the growth of algae, which will in turn affect the composition of the lake by adjusting the levels of DO, DOC, DOM pH, etc. as well as contribute to increased nitrogen uptake.
Why This Experiment?• Phytoplankton are phosphorus limited rather than
nitrogen limited (Gardner et al., 2008.)• Phosphorus deposition is linked to pollutants such as
aerosols and other anthropogenic sources• GL4 not directly influenced by anthropogenic activities• Nutrient deposition could affect quality of water from
watershed▫DOM-Alkalinity, Taste, Odor, Smell, Bi-products▫pH▫Lake eutrophication
• Could affect how water must be treated in the future
Incubation Methods• Construct Raft• Make NaH2PO4 Solution
▫ 0.1g/250mL• Spike carboys
▫ 2 Controls▫ 2 1.5umol/L (9mL
solution)▫ 2 3 umol/L (18mL
solution)▫ 2 5 umol/L (30mL
solution)• Sample each carboy• Hang carboys on raft to
incubate• Sample each carboy when
return to lake
Samples Taken▫ Chlorophyll a▫ Phytoplankton▫ DOC▫ Nutrients▫ DOM▫ pH▫ Conductivity▫ Temperature▫ DO▫ Light
Filtering and Processing Methods• Filtered and refrigerated at INSTAAR upon return
• Chlorophyll-a processed by Kathi• Nutrients processed by Kiowa Lab• Phytoplankton processed using FlowCam• DOC using fluorometer (3-D Fluorescence
Spectroscopy and UV-VIS Scan)
Where It All Went Wrong• Very late Ice-Out
▫ Could not begin until late July
• Weather▫ Battling the current ▫ Had to leave due to lightning▫ Less sun got to incubation
• Buoys and buoyant carboys▫ Couldn’t get to sink so
attached rocks▫ Too much weight for buoys,
entire raft sank▫ Only retrieved one 5 umol/L
and one 3 umol/L on return trip, from 4.9 meters
Temperature Profile in GL4
5 6 7 8 9 10 110.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
18-Jul 25-Jul
30-Jul
Temperature (°C)
Dis
tanc
e B
elow
Sur
face
(m
)
2m Cntrl A
Cntrl B
1.5A 1.5B 3A 3B 5A 5B 9.0
9.5
10.0
10.5
11.0
11.5
12.0t0
t5
Tem
pera
ture
(C)
pH Profile in GL4
5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.000
2
4
6
8
10
12
18-Jul
25-Jul
30-Jul
pH
Dis
tanc
e B
elow
Sur
face
(m
)
2m
Cntrl A
Cntrl B
1.5
A 1.5
B 3A
3B
5A
5B
5.00
5.50
6.00
6.50
7.00
7.50
8.00
8.50
9.00
9.50
t0
t5
pH
DO Profile in GL45 5.5 6 6.5 7 7.5 8
0
2
4
6
8
10
12
14
18-Jul 25-Jul
30-Jul
DO (mg/L)
Dep
th B
elow
Sur
face
(m
)
2m
Cntrl A
Cntrl B
1.5
A 1.5
B 3A
3B
5A
5B
4
4.5
5
5.5
6
6.5
7
7.5 t0
t5
DO
(m
g/L)
Fluorescence Index
2m Cntrl A Cntrl B 1.5A 1.5B 3A 3B 5A 5B1.30
1.35
1.40
1.45
1.50
1.55
t0
t5
Fluo
resc
ence
Ind
ex
Phytoplankton (Incomplete)Before Incubation After Incubation• About 10 slides/ 5mL• Mostly phytoplankton
colonies
• About 1300 slides/ 5mL• Diverse species
▫ Phytoplankton ▫ Diatoms▫ Cilliates▫ Etc…
Conclusions•Increase in phosphorus
▫Increase in phytoplankton growth ▫Increase in phytoplankton respiration ▫Increase in pH▫Increase in autochtonous DOM▫Eutrophication of lake
•Implications▫Economic- Water treatment infrastructure▫Environmental- Lake eutrophication
What Is Still Missing?•For next incubation
▫Incubate in better weather▫Phosphorus quantity specific results▫Repeated results?
•For my return to Boulder▫Increased Nitrogen uptake?▫Specific changes in algal species
In the future…
In the Future…• Smaller Carboys• Handles for the carboys• More buoys
Acknowledgements
• Advisor: Diane McKnight• Supervisor: Katherina Hell• Grad Student Mentor:
Rylee Archuleta• Pack Mules: Chris Jaros,
Rob Spencer, Katie Li, and William McKnight
• Driver: Nel• Raft Design/McGuckins
runner: Steven Crisp