Phytoplankton and the Lakes Around Us

Stephanie CoglitoreAlexis 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

Chl

a µg

/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