What happens when ponds freeze during the Antarctic winter? We decided to go to the end of the world to find out (and got more than we bargained for)…
Most scientists aren’t allowed to stay in Antarctica during winter because the risks posed by severe weather are too great. So our team characterized the microbial community in still-frozen ponds at the end of the winter. We then monitored these communities as the pond melted into spring and summer.
We found that pondwater microbes become very active as soon as melting begins. And then our work took an unexpected turn. We realized that we’d found something unique in a very microbially-active pond: a new fulvic acid reference standard.
That’s a pretty cryptic phrase – let’s break it down.
Say you need to measure something, so you pull out a ruler. How do you know that your ruler is correct? You’d have to compare it to an internationally accepted length, like a foot.
Today, we define a unit of length based on how long it takes light to travel that distance in a vacuum. But a few centuries ago, there was an institution tasked with creating and sharing copies of a “metre bar”, the one official reference standard (to which the entire world referred) for the length of a meter.
Scientists still use reference standards in a similar way. We compare a sample taken in the environment to a reference standard that helps us decide if environmental conditions there are normal (or not).
We teamed up with colleagues – from Diane Mcknight‘s group at the University of Colorado and Yu-Ping Chin‘s group at The Ohio State University – to collect samples that would become a new microbially-derived reference standard for fulvic acid.
Other fulvic acid reference standards exist and have been used by scientists for years, but these other samples were all from places where the decaying material includes components of soil. Soil-based fulvic acid has distinct and well-known differences from purely microbial fulvic acid (that is, microbes breaking down microbes).
Scientists can compare their samples to this fulvic acid reference standard from Antarctica. This will help them better understand the environments where they work.