by Corinna Gries
For hundreds of years people have collected data on lakes. Ice on and ice off dates are probably the oldest data, but water temperature, water clarity, animal and plant species and abundance have also been recorded for a long time. Scientists usually collect data to answer a specific question for which they are summarized, analyzed, graphed, and interpreted. Sometimes the conclusions are published, other times they’re used in management. Once the question is answered satisfactorily, most original data are lost (if not actively thrown away during clean up).
In recent years, however, it’s become obvious that documenting the changes going on in our climate, lakes and other ecosystems requires having data available from a long period of time. Luckily, some researchers, agencies and citizens did not clean up and kept their data – in notebooks, on index cards, in boxes or drawers, on desks, and now on computers. Here at the Center for Limnology we are lucky that data collected by early limnologists like Edward Birge and Chauncy Juday were not discarded, but are still available to us and our research. Many cardboard boxes full of handwritten numbers on index cards are stored in the University Archives and have recently been fully digitized, a fancy way of saying “hand-typed into a computer database.”
They are now part of our data archive, which is where a lot of data go that are collected by some projects at the Center for Limnology. A data archive is not so different from a regular archive or a museum. All items (datasets in this case) are cataloged and described with who collected them, when, where and how they were collected, for what purpose etc. In other words, data are curated like museums specimens.
I like to think of the CFL archive as a museum for data. The only difference is that we don’t have them in cabinets or in glass display cases, but they can still be pulled out and used to answer new research questions – questions that weren’t and, in some cases, couldn’t have been envisioned when the data were first collected. For example, in the late 1990’s researchers prepared an experiment to combat the rusty crayfish invasion of a northern Wisconsin lake. The crayfish had already been around for more than a decade and long-term datasets, including those of Birge and Juday, as well as the annual samples taken for LTER, were used to set basic parameters of northern lakes, allowing scientists to piece together what the lake looked like pre-invasion and what effects the rusty crayfish had on the ecosystem over time.
The data archive at the Center for Limnology currently houses almost 300 datasets, many of which go back 30 years to when the North Temperate Lakes Long-Term Ecology Research project started to monitor lakes. But there are also data that go back much longer, like Secchi depths for water quality and almost one hundred and fifty years’ worth of ice data. All of this information is becoming more and more valuable as we see the world around us change very rapidly. It helps us interpret the change we see and predict the future with more certainty.
Corinna Gries is a research scientist with the North Temperate Lakes-Long-Term Ecological Research project. Special thanks to UW-Madison Archives for the footage of E.A. Birge.