Spotlight
On: The Benthic Sled in Lake Superior
Spotlight
On: The Benthic Sled - our PONAR dredge collections
allow us to determine the number of organisms living in the
sediment, but only yield a few dozen animals per sample. Our
scientists wish to collect Diporeia and determine their content
of lipids (a measure of health and value as a food for fish),
carbon and stable isotopes (an alternative measure of biomass
and indicator of their food sources) and synthetic organic
chemicals (a measure of contamination). For this we need the
benthic sled. This huge net in a sled-like frame is towed
at depth behind the boat for about ten minutes and brought
to the surface and harvested. Literally kilograms of Diporeia
and Mysis are collected. The samples must then be ‘picked'
in the laboratory, separating the animals from the detritus
and processing them for storage and later analysis. Return to Cruise
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Benthic
sled on fantail
|
Detail
of benthic sled
|
Up it comes |
Over it goes |
Dr. Nancy Auer
|
Winching the benthic sled from Lake Superior |
Back on board |
Removing the catch |
What
was caught in the benthic sled
|
See
the Benthic Sled Movie near Au Train Island
WMV
2.9 Mb
WMV
Hi - Res 5.2 Mb |
Filtering
ponar contents |
Filtrate
into a storage jar |
Return to Cruise
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Copyright © 2006
Civil & Environmental Engineering Department at Michigan Tech
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