Two billion diatoms at our service | Science Museum of Minnesota

Field Notes
Field Notes

Two billion diatoms at our service

Thursday, June 29, 2017
Posted by
Greg Seitz

Diatom fossils collected from the St. Croix River to help determine natural water quality conditions and guide restoration work.
(Courtesy David Burge and Mark Edlund)

As the field station of the Science Museum of Minnesota, the St. Croix Watershed Research Station is focused on scientific research — and we have pretty impressive collections, too! To celebrate International Museum Workers Day today, here is some info about our archives:

In our diatom archive, we have 10,057 individual slides that represent 57 separate projects and 445 different lakes, ranging from Minnesota to Manitoba to Mongolia. Those slides hold approximately 2 BILLION diatoms of numerous species. Our scientists have identified and counted more than 300,000 of them.

Because these types of algae are very sensitive to changes in water chemistry and other environmental factors, studying how the numbers of different species have changed over times is a reliable way to reconstruct the historic conditions of lakes and rivers and guide restoration goals. This archive has also helped our staff identify 50 new species!

We also have about 680 sediment cores archived, representing 70 different projects going back to 1985. Each archive contains about 100 individual intervals, totaling approximately 32,600 vials filled with sediment. That mud can tell us how much erosion occurred in a watershed in the past, or what kinds of algae were present.

These collections have provided great information for past studies, and can continue to be valuable far into the future.