Funded by LBAYS: A journey into the brown waters of Evo

Morgane Ducoin has visited at Lammi Biological Station twice, participating in projects that delve into the research of "water browning." Water browning means the phenomenon where certain water bodies gradually darken, inducing profound changes in aquatic ecosystems.

I’ve lived at the Lammi Biological Station twice, both times working as part of projects that research “water browning”. Water browning refers to the fact that some water bodies tend to grow darker over time, and it can cause profond changes in aquatic ecosystems. I’ve conducted both my studies in the nearby Evo forest, where several lakes and ponds have become browner in the last decades.

I first arrived in 2021 to study how drainage can cause the browning of lakes. Ditching is a common technique used in sylviculture to dry wetlands and improve tree growth. It has been largely employed in Finland, so a consequent portion of the land is concerned. Yet, the study of ditches’ impact is limited because we lack accurate maps of them. To take a first step in this direction, I worked to produce a map of Evo’s drainage network, by compiling data and using geomatic tools. In parallel, I made field checks in Evo, and they indeed revealed discrepancies between current maps and potential ditches going under the radar.

Exploring the varied responses of aquatic invertebrates to water browning phenomenon in different habitats

When coming back in 2022, I then got myself interested into aquatic invertebrates, and how they respond to this water browning phenomenon. Aquatic invertebrates represent a major share of freshwaters’ biomass and they are a key component of their food webs. Research had already raised the alarm, because aquatic invertebrates have been shown to decrease when waters get browner in lakes; but what about other habitats?

In Evo once more, I sampled and identified aquatic invertebrates in 5 lakes, as well as in 5 beaver ponds and 5 temporary ponds, with water color monitored in parallel. I repeated the process three times over the 2022 May-June period to account for seasonal changes. Analyses showed that the diversity of macroinvertebrates tends to reduce when waters get darker. Surprisingly though, I have found that macroinvertebrates tended to be more numerous in moderately brown temporary ponds as compared to clear ones. It was mainly coming from mosquito larvae, which can abound in temporary waters. These results enlighten the fact that consequences of water browning are intricate and can vary when focusing on specific species or different habitats.

Both my stays at Lammi happened during the covid-19 pandemic. While medias from my homeland were telling me that the rest of world had stopped spinning, I must confess I didn’t suffer as much from it. Luckily for me, I worked mostly outdoor or behind a computer, and so my job wasn’t too disrupted. During these hard times, the station was like a remote cocoon of pure nature, where I’ve been able to freely enjoy work and human relationships.

Life at the station

Life at the station was nothing but a breath of fresh air, in every meaning of the word. Being surrounded with scientific minds from all around the world is an every-day blessing. We share our cultures and opinions in a genuine way, and I grew wiser from it. We undoubtedly have different points of view, but it is a solid strength in science, for others see things in a way that we simply could’ve have thought of. Cherry on top was that I got to know and contemplate other subjects than mines, sometimes even helping on them. Surely such environment had me thrive on both professional and personal plans; I’ve benefited from my friends’ help and insights just like, or so I hope, I’ve been able to benefit them. Now that I’m back to my everyday life, I often find myself missing this welcoming, mind-opening place and all the heartening and inspiring people I’ve met there.

This experience will stick to me for a while. And so I thank Lammi Biological Station for housing me and the foundation for supporting my work.

More research funded by LBAYS