BIOMASS AND COMPOSITION OF THE PHYTOBENTHOS: AN HPLC APPROACH

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BIOMASS AND COMPOSITION OF THE PHYTOBENTHOS AN
HPLC APPROACH
Kari Galván and John Fleeger Louisiana State
University
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Introduction and relevance

• Photosynthetic organisms found on and in the top
  centimeter of sediment
• Filamentous algae
• Macroalgae
• Diatoms
• Cyanobacteria
• Important food source
• EPS biofilms

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Introduction cont.

• Biomass
• Flourometry
• HPLC
• Biomass
• Taxonomic composition
• Pigments characteristic
• of specific groups
• Degradation

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My Interests

• Biomass and community composition
• Spatio-temporal changes in biomass and
• community structure
• Changes in biomass and community structure with
  treatments
• (fish removal and nutrient addition)

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Methods

• 2004
• Sediment pigment cores (1 cm depth)
• SW and WE only
• Monthly
• June through August
• 5 habitats
• 2 reps per branch
• Epipelic diatom collections for taxonomic
  identification
• SW and WE only
• Monthly
• June through August
• MF only
• 2 reps per branch

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Methods cont.

• 2005
• Sediment pigment cores
• SW, WE, CL and NE
• Monthly
• May through Sept
• 5 habitats
• 2 reps per branch
• Exception 5 reps taken for MF and FA habitats
  in all creeks for Sept only
• Epipelic diatom collections for
• taxonomic identification
• SW, WE, CL and NE
• Monthly
• May through Sept
• MF only
• 2 reps per branch

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Todays Talk

• HPLC only
• 2004
• SW and WE
• June and August
• 2005
• SW and WE
• September

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Accessory pigments and stats

• Accessory pigments
• Zeaxanthin - cyanobacteria
• Lutein and Chl b - green algae and macrophytes
• Diadinoxanthin - lesser pigment in diatoms
• Fucoxanthin - major pigment in diatoms
• Stats
• Community composition
• Primer
• Chl a
• Anova

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Habitat comparison WE-L
Significant differences in community composition
(p-value .04)
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WE and SW (T0)


Significant differences in community composition
for FA and SP with dissimilarities highest for
Chl a
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WE branch comparison
No significant difference for community
composition between branches
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WE-L June and Aug 2004
No sign. differences in community composition,
Chl a differences for FA and MF
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WE fish treatment Aug 2004

Significant difference for community composition
in SP only
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WE-L SW-L Aug 2004
No significant differences in community
composition significant differences for Chl a
in TSA only
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SW-L T0 (nutrients) and after 2 seasons of
nutrient addition
No significant differences in community
composition, significant difference in Chl a for
MF, SP and SSA
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WE-L and SW-L Sept 2005


Significant differences in community composition
for FA and MF Significant differences in Chl a
for FA, MF and SSA
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Summary

• Natural community composition differs between
  habitats for control branch and over time for FA
  only
• No treatment effect on community composition at
  end of first season
• Nutrients or fish (SP exception)
• Nutrient treatment effect on community
  composition and Chl a at end of second season.
• FA and MF and for FA, MF and SSA respectively
• Differences due to Chl a

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Future Work

• Run remaining HPLC samples
• Diatom taxonomy
• microscopy
• Degradation
• grazing

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Acknowledgements

• - National Science Foundation
• - Marine Biological Laboratory (MBL)
• - Dr. Linda Deegan (MBL)
• - Mike Johnson (MBL)
• - Christian Picard (MBL)
• - The Marshview Gang

COMMITTEE MEMBERS Dr. John Fleeger Dr. Brian
Fry Dr. Bruce Peterson Dean Kevin Carman
I would like to thank the D. Samuel Johnson
School of Primer and Pivot Tables.