Author: Wanja Böhme, Pictures: Lukas Krause
It’s 08:15 at the peer, the sun has been up for three hours already. People are running around, loading boxes with bottles and canisters on Wassermann, Rita and Peterchen – the boats of the KOSMOS campaign.
Every second day we drive out to sample the mesocosms. Of course, I checked the weather the night before, knowing I could not trust whatever my app might tell me. It didn’t look promising.
But now when Rita is unleashed, ready to drive out, there’s not a single cloud in the sky. The water is calm, flat as a pancake. Rita easily cuts through the undisturbed waters, flying to the ten mesocosms hiding behind one of the many islands. The drive is short and after 5 minutes we arrive at the first floating oversized plastic bag hanging inside the flotation frame, consisting of six orange pillars. The visibility into the water is great and you can see the metal frame and the lines connecting the mesocosms at ~5m depth.
On board we have something called an integrating water sampler (IWS) next to all the canisters for the samples. Basically, an IWS is a fancy bucket attached to a rope to get water from the mesocosm into our canisters. It tracks its depth in the water column and collects water through the entire 20 meters inside the mesocosm. This way we ensure to sample the whole water column evenly.
However, there’s one catch with these samplers, they have to be lowered slowly otherwise the device won’t fill properly, stop halfway and bring up only a part of the water column. Quickly people came up with interesting ideas on how to go as fast as possible to save time without going too fast to cause a fail. The strategies ranged from humming to “Stayin’ alive” (too fast) to singing along to “Hallelujah” (too slow) or chewing gum to keep the paste.
On this particular day, we were lucky with the weather and sampling was a blast. Coming back slightly sunburned, we realized it is possible to not be soaked after sampling. However, we also knew it would take a while until we would have another sampling day like this.