Tomas Brodin

Tomas Brodin was born in 1971 in Umeå but grew up in Djäkneböle, a small village 20 km southwest of Umeå shaped by agriculture and forestry. After military service, he studied biology at Umeå University and graduated in 2000. He continued with doctoral studies in evolutionary ecology at the same university and received his PhD in 2005 with a thesis on how predators affect their prey populations. After that, he went to UC Davis for a 2-year post-doc funded by the two Swedish research councils, Formas and VR. In California, he studied behavioral ecology with a special focus on what determines which individuals disperse and why they choose to do so. In 2009, he returned to Umeå University where he has since been active, and in 2017 he was appointed as an associate professor in ecology. Since his return from California, Tomas's research has mainly focused on two parallel tracks related to human impact. He has, among other things, studied how alien species affect the ecosystems they invade and what determines whether the invasion is successful or not. But in recent years, his research has primarily focused on how the drugs we use, which then end up in our waterways, affect animals and, ultimately, change entire ecosystems. Since 2018, Tomas has been a professor in, and subject area coordinator for, Aquatic Ecology at Wildlife, Fish, and Environment at SLU in Umeå.

Ecological effects of pharmaceuticals in aquatic environments

We have all taken medicines at some point, but very few have probably thought about the fact that medicines can be harmful to the environment. Today we consume more medicines than ever, and due to a growing number of people on earth and an increasing proportion of elderly people, the use of medicines is expected to increase dramatically in the coming decades. As a consequence of this, never before have so many medicines been released into water bodies around the world as now. Since most medicines are designed to be functional and stable in the body, they usually leave the body as an active pharmaceutical. They then end up in a treatment plant, but since treatment plants are unable to remove many pharmaceuticals, they continue into the ecosystems where the treatment plants discharge. In these lakes, streams, or rivers, aquatic animals, such as fish and aquatic insects, have to live in (and are affected by) a mixture of medicines and water. The animals breathe, drink, and therefore live in pharmaceuticals 24 hours a day. In my research, I combine controlled experiments in the lab with realistic studies out in actual lakes and rivers. Primarily, I investigate how behavior-modifying pharmaceuticals affect the behaviors of fish and how this effect in turn impacts species and ecosystems. My collaborators and I have previously demonstrated strong effects on several important behaviors (e.g., risk-taking, activity, and social tendency) in fish at concentrations on the level of those measured in watercourses in Sweden and around the world today. These behavioral changes affected the fish's ability to catch and eat food as well as their ability to avoid being eaten. One group of pharmaceuticals that, according to my results, already today affects organisms in watercourses around the world is benzodiazepines. This group is among the most used, and also the most discharged, of all psychotropic drugs. They are used to treat anxiety in humans and are now found in surface water and drinking water globally. Despite the legitimate concern about the release of psychopharmaceuticals into nature, there are still very few studies on the ecological consequences that benzodiazepines have in aquatic ecosystems. This is alarming because they are manufactured to modify behavior and the receptor affected (GABA) is present in the majority of all vertebrates. It is therefore not surprising that I, in previous studies of a benzodiazepine (oxazepam), observed significant behavioral changes in perch, roach, and salmon at concentrations corresponding to those measured in water from, for example, the Fyris River near Uppsala. Moreover, pharmaceuticals have been shown to accumulate in fish and aquatic insects, and recently I was able to show that the accumulation increases with rising temperature, which suggests an increased risk of ecological effects in a warmer future climate. Therefore, I have just initiated a project that studies how the risk of ecological effects of pharmaceuticals in the environment is affected by a warmer climate.