The following article originally appeared in the Kenora Miner
& News. It is reproduced here with the permission of
the Kenora Miner & News.
Kenora Miner & News
Elsie Neufeld
Jan. 2002
Sediment stories come from digging into the lake bottom
By Elsie Neufeld
Miner and News Staff
If the bottom of Lake of the Woods could speak, what story
would it tell?
Part of that story will surface this winter when a team of
researchers and volunteers draw sediment core samples from the
lake bottom. The coring project will happen as soon as the ice
roads are right and funding details are clarified - probably
in February, said Mike Staiton, an aquatic chemist at the
Department of Fisheries and Oceans Fresh Water Institute in
Winnipeg who is heading up the project.
This isn't the first time core samples have been taken but
previous samples cannot reveal the information sought.
"Unfortunately they haven't been dated," said
Staiton.
About 15 years ago, someone from the University of Toronto
took samples but attempts to track down these samples haven't
been successful. These new cores will provide several agencies
with valuable information.
Two types of sites are to be sampled: one to reveal the
general history of the lake and the other to address specific
issues, explained Staiton.
Sediment layers can show environmental changes such as the
impact of human development on the lake, the concentration of
greenhouse gases at certain times and the productivity of
algae blooms.
Lake of the Woods District Property Owners Association has
expressed concerns about algae blooms in recent years and is
contributing some of the funding for this project.
Staiton said anecdotal evidence tells that algae blooms
have always been on the lake. References to algae dates back
to when La Vérendrye passed through the area. The sediment
layers can show the history of algae in the lake. The core
sample will show about 150 years of lake bottom history.
The team will sample from eight sites which cover all
regions of the lake - north, south, east and west and some
specific sites such as the South Basin, Whitefish Bay,
Clearwater Bay and Big Poplar Bay.
The sampling team will be made up of four to six people on
two or three snowmobiles. The sampling equipment is relatively
lightweight and compact, said Staiton. It is mainly a long
acrylic tube that sinks into the mud. When the tube is filled
with about a metre worth of sediment, a trap door closes
creating a vacuum so the sample can be drawn up. It also keeps
the water turbulence from disturbing the top rings.
The sampling can only be done in the winter because it
needs to be performed from a stable platform.
"To do it accurately you have to make sure the coring
device goes in perfectly vertical." So this can't be done
in the summer from a boat bobbing about on the lake
surface."
The
Lake of the Woods District Property Owners and the Kenora
regional office of Fish Habitat division of Fisheries and
Oceans are also interested in the story the lake bottom has to
tell. They will provide logistic support to the Fisheries and
Oceans researchers when they carry out the project.
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