The Great Lakes March-October 2001

 

The Great Lakes

 

* This exhibit is no longer on display *

Introduction / Equipment Used to Collect Samples

 

About the Exhibit

About the Exhibit

As we enter the second millennium, we have finally come to a realization: It is the very enormity of the Great Lakes –the same attribute that allows them to absorb the insults inflicted upon them- that also makes it so very difficult to address the impacts that result. This exhibit is an attempt to raise awareness that while a host of issues face the Great Lakes, the United States and Canada have spent the last quarter century joined in an effort to identify ways to address them and a commitment to do so.

About The Great Lakes National Program Office…

The Great Lakes National Program Office of the United States Environmental Protection Agency represents the cornerstone of

the U.S. Commitment to the Great Lakes Water Quality Agreement with Canada. The Program carries the nation’s lead responsibility for monitoring the health of the Great Lakes, operating the Research Vessel, Lake Guardian in an annual effort to gather ambient data on nutrients, contaminants, biota and atmospheric deposition. It also leads the Agency’s efforts to find innovative solutions to the problems of contaminated water, sediment and biota, identifying ways of preserving and restoring habitat, and addressing invasive species issues.


Great Lakes Monitoring


Open Lake Monitoring

Open Lake Monitoring

The U.S. EPA operates two open water research vessels on the Great Lakes. The Lake Guardian, pictured here is the largest, at 180 ft. It carries a crew of up to 35, including up to 25 researchers, with five laboratories. It plies all five Great Lakes and their connecting rivers annually to collect samples of water, sediment plankton and air.


Plankton Sampling
Illustrations: Washing plankton From net into collection jar , Diatomaceous algae, Navicula miniscula, Filamentous algae,
Stephanidiscus bonderana,
A native crustacean, Daphnia sp.,
An exotic crustacean, Bythotrephes sp.

Plankton Sampling

Working from research vessels such as the EPA’s R/V Lake Guardian, scientists gather tiny plants (phytoplankton) and animals (zooplankton).

Plankton float or swim freely in the open waters of the Lakes. As in the oceans, phytoplankton form the basis of the Great Lakes food chain. Zooplankton, mussels and many small fish feed on phytoplankton. The zooplankton form an important second step in the food chain as they provide a more concentrated energy source to small fish and fry (very young) of larger fish. Scientists filter metered volumes of water using plankton nets to collect specimens to determine plankton populations and identify changes in the its community structure.


Atmospheric Contaminant Sampling

Atmospheric Contaminant Sampling

High Volume Air Sampler
The metal cartridge displayed here contains an adsorbent resin that will take up organic vapors from the air. The high volume sampler is used to draw a known, large volume of air through the cartridge. In the laboratory, the chemicals will be extracted into solvents and analyzed.

Precipitation Sampler
The long transparent tube contains a resin similar to that in the high volume sampler, but it is used to extract atmospheric contaminants that have been dissolved in precipitation. As with the high volume air sampler, the resin column captures the dissolved chemicals for laboratory analysis.

 

 

 

 

Precipitation Sampler
Precipitation Sampler


Nisken Bottle Water Sampler

Niskin Bottle Water Sampler

The Niskin bottle is a long plastic tube that is lowered into the water open at both ends. Water passes freely through the bottle. When it reaches the desired depth the researcher can “fire” or close both ends of the bottle to capture a sample of water from that specific depth. Once the bottle is retrieved, the water is drained out through a plastic tube into other equipment for measurement or subsampling.

A Niskin bottle can be employed individually and “fired” by sliding a weight down the cable to spring the mechanism. Alternatively, on a properly equipped research vessel, the Niskin bottle may be arrayed with several others in an elaborate apparatus to collect numerous samples from many depths, such as the “rosette” sampler pictured here. The bottle array is often combined with instrumentation providing continuous, recorded readouts of several parameters as the sampler descends.



Nisken Bottle Water Sampler
Niskin Bottle Water Sampler

 


Acknowledgments: The exhibit was written and complied by Robert Beltran -USEPA Great Lakes National Program Office.
The exhibit was organized and maintained by Barbara Kern - John Crerar Library, University of Chicago.

For more information about exhibits at the John Crerar Library,
please contact Barbara Kern at 773-702-8717 or bkern@midway.uchicago.edu.

B.Kern, Crerar, 2002
Photographs of the exhibit courtesy: B. Kern

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