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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.
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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
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 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 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 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 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 Lakes Analysis • Chlorophyta was the only division present • Phosphorous must be abundant, and that’s about the only thing in Green Lakes
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