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Center
for Embedded Networked Sensing |
| Two
years of investigations into phytoplankton and ecosystem dynamics
in Lake Fulmor, CA using the NAMOS network |
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Beth Stauffer, Stefanie
Moorthi, David Caron, Gaurav Sukhatme, Carl Oberg, Bin Zhang, Amit
Dhariwal, Arvind Menezes-Pereira
University of Southern California, Department of Biological Sciences,
Computer Science Department
http://robotics.usc.edu/~namos |
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| Introduction:
Plankton Communities in Aquatic Environments |
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Phytoplankton communities in lake
ecosystems
• Communities may be diverse or dominated by one or few species
• The environment that phytoplankton experience is highly dependent
on water stratification and flow
• These parameters are highly variable on both spatial &
temporal scales
• Blooms of potentially toxic cyanobacteria & overall eutrophication
an important issue for lake ecosystems
• Light extremes & nutrient stress may alter the photosynthetic
efficiency of phytoplankton, which is still poorly understood.
Study Site: Lake Fulmor, San Jacinto
Mountains, CA
• Subalpine lake, altitude ~5000ft.
• Maximum depth: 6m
• Low flow but relatively strong discrete wind events
• Observed surface scum formation during wind events
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| Problem
Description: Networked Aquatic Microbial Observing System (NAMOS) |
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Combined mobile &
static components for estimating phytoplankton biomass & water
structure
• Temperature sensors provide information on water column stratification
• surface - 2.5 meters
• Chlorophyll fluorometers estimate phytoplankton biomass near
the surface
• Meteorological instrumentation, including wind speed &
direction which influence surface water currents & temperature.
• Active fluorometer & NIMS RD provided additional sensor
information (pH, DO)
• Discrete samples for nutrients, microscopical analysis, toxin
& molecular analyses.
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Proposed Solution: Diverse Sensors
and Techniques to Characterize a Dynamic Community |
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• Fluorometer data
(blue line) and Phytoflash yield (green line) from August 2006.
• Phytoflash fluorometer (Turner Designs) uses ‘active fluorescence’
to estimate efficiency of light absorption in photosynthesis.
• Data shows lower efficiency:
• during night hours, when there is no light for photosynthesis
• at mid-day, when light is supra-optimal & can cause cellular
damage |
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Thermal Stratification increases
throughout the 2006 season, with implications for the mixing regime
& phytoplankton distribution. |
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We observed a large chlorophyll
peak at 3m depth in August 2006.
• Isolated small green flagellate from samples |
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Thermal Stratification increases
throughout the 2006 season, with implications for the mixing regime
& phytoplankton distribution. |
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We sequenced a portion (~150bp)
of the 18S rDNA of the small flagellate, which matched most closely
(98%) to Trachelomonas hispida, a bottom-dwelling Euglenoid whose
ecology is still largely unknown (Reynolds, et al, 2002. |
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UCLA – UCR –
Caltech – USC – UC Merced
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