phytoplankton and the lakes around us stephanie coglitore alexis krukovsky jamie nelson
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Phytoplankton and the Lakes Around Us
Stephanie Coglitore
Alexis Krukovsky
Jamie Nelson
Purpose
• To observe and quantify the relationships between phytoplankton concentration, diversity and chlorophyll concentration.
• Hypothesize how the relationship between these parameters contributes to the overall trophic state of the lakes
Data Collection
• Kimmerer bottles
• Samples taken from different depths of epi, hypo and metalimnion
• preserved in ethyl alcohol
Why are Phytoplankton and Chlorophyll Important?
• The density and specific species of phytoplanton present will directly affect chlorophyll concentration
• Phytoplankton biomass is directly correlated with productivity and photosynthetic ability within a system
• Means of estimating the energy pathways in an aquatic system
Why Chlorophyll a?
• Chlorophyll a is the best measurement since all phytoplankton contain chlorophyll a but differ in composition of other pigments
Analysis of Phytoplankton
• Resuspend sample by mixing and filter 250ml onto filter paper
• Remove filter, fold in half and put in aluminum foil
• Place foil in bottle filled with desiccant and place bottle in freezer for storage
• Rinse filter head between samples
Phytoplankton cont.
• Samples should be resuspended in ethyl alcohol and allowed to concentrate over several days
• Refilter the samples
• Identification by genus and division under dissecting microscope
Analysis of Chlorophyll a
• Samples treated with ethanol to separate out chlorophyll
• Separated samples were filtered and measured using a flourometer
• Conversion:
Chlorophyll a conc..= (F0*VE)/VS
Fluorometer Method• Fluorometer was used to measure
chlorophyll a concentration in the samples from different depths
• Determination of chlorophyll is more efficient, if not quite as accurate as microscope way
• Add ethanol to filtered sample to extract the photosynthetic pigments
• Prepare a blank filter-acts as a control
Fluorometer Method
• Invert each tube to mix thoroughly
• Leave sample in meter for no longer than 10 secondscould cause more production
• Fluorometer was used to measure chlorophyll a concentration
• Chlorophyll a can be used as an indicator of primary production
Counting Phytoplankton
• To count cells, both the Palmer-Maloney slides and the sorting trays were used
• Counting 100 individuals/10 taxon is enough for statistical accuracy
• Subsample of community, can extrapolate data and apply it to the whole lake
• Phytoplankton can be used as an indicator of primary production
Lakes By Division and Total
0%
20%
40%
60%
80%
100%
Oneida Arbutus Rich Catlin Onondaga Green
Lakes by Number of Divisions
Total
# of Divisions
What Dominated in Each Lake?
Lake Dominated By Category
Oneida Chrysophyta (Bacillariophyceae) Diatoms
Arbutus Chlorophyta and Chrysophta (Bacillariophyceae) Green algae; Diatoms
Rich Chlorophyta Green algae
Catlin Chlorophyta and Chrysophta (Chry) Green; Golden algae
Green Chlorophyta Green algae
Onondaga Chlorphyta Green
Oneida LakeOneida Lake Phytoplankton by Division
Cyanophyta
Chlorophyta
Chrysophyta(Bacillariophyceae)
Oneida Lake Analysis
• What does it all mean?
• Lots of Chrysophyta Bacillariophyceaediatoms, lots of silica present here
• Fairly shallow because they would sink to the bottom, must be constantly mixing
• Nitrogen is not an issue here
Rich LakeRich Lake Phytoplankton by Division
Cyanophyta
Chlorophyta
Chrysophyta(Bacillariophyceae)
Rich Lake Analysis
• Dominated by Chlorophyta, indicating a high level of phosphorous
• Cyanophyta also represented probably due to lack of nitrogen
• Must mix regularly to have a sizable population of diatoms
Catlin Lake
Catlin Lake Phytoplankton by Division
Chlorophyta
Chrysophyta(Chrysophyceae)
Catlin Lake Analysis
• Green and golden algae were the only two present
• Even split, so it has a good amount of phosphorous and silica
• Not enough silica to support Chrysophyta (Bacillariophyceae), perhaps due to lack of it in sediments
Arbutus Lake
Arbutus Lake Phytoplankton by Division
Cyanophyta
Chlorophyta
Chrysophyta(Bacillariophyceae)
Pyrophyta
Chrysophyta(Chrysophyceae)
Pyrophyta
Euglenophyta
Cryptophyta
Arbutus Lake Analysis• Little bit of everything, perhaps because it has a
lot of drainage
• No one division dominates, Greens at 26%, Diatoms at 21%, and Blue-greens at 16% make up the top three divisions
• Must have a good amount of diatoms and phosphorous
• Probably limited in nitrogen considering the blue-green algae
Onondaga LakeOnondaga Lake Phytoplankton by Division
Cyanophyta
Chlorophyta
Euglenophyta
Pyrophyta
Onondaga Lake Analysis
• Such a surprise, dominated by Chlorophyta
• 64% of algae represented green algae, with 16 out of 25 genera
• Lots of phosphorous input from sewage
• Lack of nitrogen evident because of the presence of Cyanophyta, which makes up 24% of the genera present
Green LakesGreen Lakes only Phytoplankton by
Division
Chlorophyra (Pediastrum)
Green Lakes Analysis
• Chlorophyta was the only division present
• Phosphorous must be abundant, and that’s about the only thing in Green Lakes
Catlin Lake Chlorophyll Data
0
25
50
75
100
125
150
175
Ch
la µ
g/L
1Epi
1Epi
8.5Meta
8.5Meta
11Hypo
11Hypo
depth (m)
Catlin Lake Chlorophyll a Concentration
Rich Lake
0
50
100
150
200
250
300
chla
µg
/L
1Epi
1Epi
8Meta
8Meta
10Hypo
10Hypo
depth (m)
Rich Lake Chlorophyll a Concentration
Arbutus Lake
0
50
100
150
200
250
300
350
chla
µg
/L
1Epi
1Epi
5Meta
5Meta
7Hypo
7Hypo
depth (m)
Arbutus Lake Chlorophyll a Concentration
Oneida Lake
2500
2600
2700
2800
2900
3000
chla
µg
/L
1Epi
3Meta
5Hypo
depth (m)
Oneida Lake Chlorophyll a Concentration
Onondaga Lake
0
200
400
600
800
1000
1200
chla
µg
/L
1Epi
4Epi
8Meta
10Meta
15Hypo
17Hypo
18Hypo
depth (m)
Onondaga Lake Chlorophyll a Concentration
Green Lake
119 95.1
42.9
217 292
1710
41.3 17.6 14.9
91.5 80.7
0
200
400
600
800
1000
1200
1400
1600
chla
µg
/L
3 8 15 22.5
31 3 8 15 22.5
31
epi epi meta hypo hypo purple epi epi meta hypo hypo
depth (m)
Green Lake Chlorophyll a Concentration
Sources of Error???• Chlorophyll analysis only accounts for
Chlorophyll a
• Flourometer does not separate phaeophytin from chlorophyll sample
• Many phytoplankton are too small and may pass through nets
• Not all of the phytoplankton in the samples were counted only the first 100 specimens
Sources of Error continued
• Our inexperience at counting and identifying phytoplankton
• Sample sizes for phytoplankton were often very small- Green Lakes had 1 algae counted
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