By Kristin TePas
|In July 2011, scientists and educators from around the Great Lakes will be aboard EPA’s Lake Guardian research vessel to research environmental conditions in Lake Superior, and share their stories.|
Let the research begin! We did our first sampling station Thursday at the Coordinated Science and Monitoring Initiative (CSMI) site. The teachers rotated through each piece of sampling equipment and each gained hands-on experience helping out the scientists and marine technicians.
We first deployed the Rosette to collect water samples for water quality analysis. The Rosette has a central cylinder where a sensor package is located and clustered around that package are sampling bottles. For more on Rosette samplers. Water samples were collected at different, discrete depths throughout the water column. To determine the discrete sampling depths, temperature is used by measuring the thermal stratification the term for the temperature layering effect that occurs in water) of the lake. In the summer months there is a distinct warmer upper layer called the epilimnion (e.g., 12-15C) with a rapidly decreasing layer beneath leading to a uniform colder layer called the hypolimnion (e.g., 4 C).
We next deployed phytoplankton and zooplankton nets to collect algae and zooplankton.
Phytoplankton were collected from the upper productive layer of the water column, while zooplankton were collected throughout the water column. Scientists will analyze the abundance and composition of these communities because as the base of the food chain, they support the entire system!
We then collected sediment using a PONAR grab sampler which was named after Great Lakes scientists, Charles E. Powers, Robert A. Ogle, Jr., Vincent E. Noble, John C. Ayers, and Andrew Robertson.
This sampler allows us to examine the benthic zone, or the lowest level of the lake’s ecosystem. With these samples, grabbed
from the lake bottom, scientists will look at the benthic organisms that live in the sediment, total organic carbon and plastics. The collection of plastics is for Dr. Rios-Mendoza (University of Wisconsin-Superior), who is studying the abundance and composition of plastics polymers in aquatic environments.
The teachers will get plenty of experience using the equipment and processing samples as we’ll be sampling at many more CSMI sites over the next several days!
Got a question about the equipment? Then send a question to the Lake Guardian mailbag for our experts to answer!
About the author: Kristin TePas works with IL-IN Sea Grant as an outreach specialist and is a liaison to U.S. EPA’s Great Lakes National Program Office.
Editor’s Note: The opinions expressed in Greenversations are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.