Professor Maren Voss
The 2022 Björn Carlsons Östersjöpris is awarded to Professor Maren Voss of the Leibniz Institute for Baltic Sea Research in Warnemünde, Germany.
Professor Maren Voss is being awarded the prize for her groundbreaking research on the importance of marine nitrogen, particularly in the Baltic Sea. Professor Voss realised early on that nitrogen plays a vital role in Baltic eutrophication and has used advanced isotope analyses to map the transformation processes and sources of nitrogen in the Sea. Her research has increased the focus on nitrogen in efforts to counteract Baltic Sea eutrophication.
The prize motivation is:
The Björn Carlsons Östersjöpris 2022 is awarded to Prof. Dr. Maren Voss, Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Rostock, Germany
The prize is given for her pioneering research on the importance of nitrogen as a nutrient in the ocean, and especially the Baltic Sea. Professor Voss realized early the central role nitrogen plays in the eutrophication of the Baltic Sea, and has used advanced isotope analyses to map the sources and cycling of nitrogen in the ocean. Her research has led to greater emphasis on nitrogen abatement in the management of Baltic Sea eutrophication.
Introduction to the research area: Eutrophication results from an excess of nutrients, particularly nitrogen and phosphorus, entering lakes and oceans. The sources of excess nutrients are human activities, such as the use of fertilizers in agriculture or release of untreated wastewater. Nutrients stimulate plant growth, and too much can lead to massive blooms of algae, including toxic cyanobacteria. These blooms can adversely affect the ecosystem, either directly, or indirectly, when they decompose and strip the water of oxygen. In this way eutrophication can push the sea over its ecological thresholds, resulting in a disturbed ecosystem.
Detailed justification for the nomination: Maren Voss was the first in the Baltic Sea region to use the method of measuring stable isotopes in water and organic matter, to decipher processes and identify the origin of nutrients. Her laboratory is still a leader in the application of this method to identify sources of eutrophication and to understand critical processes of the nitrogen cycle. For the Baltic Sea, for example, she has described for the first time that eutrophication from rivers leaves a clearly detectable signal in the biota of the Baltic Sea. Similarly, she and her colleagues were first to describe that not only the large colonial cyanobacteria fix nitrogen, but also unicellular species.
Her continued work at the highest scientific level has led to a better perception of the problems of the Baltic Sea also in the international context. She has pointed out in various media interviews and publications that a lower meat consumption is an effective means of reducing nitrogen inputs to the Baltic Sea. She has also made important contributions to several very successful EU projects and trained young scientists who are still working for a healthier Baltic Sea today.
Description of the awardee’s research: Maren Voss has worked on the nitrogen cycle of the Baltic Sea for over 25 years and published close to 70 studies on this topic. The measurement of microbial rates and their extrapolation to construct budgets as well as important method developments (e.g nitrogen fixation measurements) were central elements of her work.
Her early work showed that 15N values are elevated in the Baltic Sea, demonstrating that eutrophication by river-borne nutrients is indeed detectable in the Baltic Sea. She also showed that in addition to rivers, precipitation and nitrogen-fixing microorganisms are important nutrient sources for the Baltic Sea. Based on these results, the Swedish Environment Protection Agency invited her as one of five experts to write a report on “Eutrophication of the Seas along Sweden’s West Coast”. The report stressed the essential role of nitrogen for eutrophication in this marine area, modifying a previous focus on phosphorus. She also participated in a workshop that proposed that internal ecosystem feedbacks described as a “vicious circle” complicate management of Baltic Sea eutrophication, and require reduction of the external loads of both nitrogen and phosphorus. With her Baltic Sea expertise, she also collaborated in the European Nitrogen Assessment, which stressed the problematic role of pollution by nitrogen compounds in the environment and the need to regulate them, both in the Baltic Sea area, and for all of Europe.
Much of Maren Voss’ research has focussed on the role of nitrogen-fixing cyanobacteria in the Baltic Sea, to answer fundamental questions such as: How much do they fertilize the Baltic Sea? How can fixation rates for entire basins be better quantified? How can new nitrogen-fixing organisms in the Baltic Sea be identified? How is fixed nitrogen transferred through the food chain? Answers to these questions were provided in numerous publications, and her research group was first to detect nitrogen fixation by singe-cell cyanobacteria in the Baltic Sea.
Maren Voss and her collaborators have shown that the nitrogen balance of the Baltic Sea is still far from understood. A hypothesis they developed suggests that the Baltic Sea nitrogen cycle differs between the coastal regions and the open sea, with most of the combined nitrogen emanating from land in coastal regions, but from nitrogen fixation by cyanobacteria in the open sea. One reason for this is efficient denitrification in the coastal zone that removes much combined nitrogen before it can reach the open sea.
Influence of Maren Voss’ work on the Baltic Sea environment: Her work has become a cornerstone in our understanding of Baltic Sea eutrophication and how to combat it. Her continued cooperation with Baltic Sea colleagues in many EU projects has produced recommendations for EU and HELCOM that have influenced Baltic Sea eutrophication management. Based on her pioneering work on river-borne nitrogen isotopes, 15N values are used today as a standard indicator of eutrophication.
A further contribution by Maren Voss is her important work educating students on the complexity of the nutrient cycling and the potential of stable isotopes for the quantification of nutrient inputs. These activities include teaching at her home University of Rostock, as well as international courses, and an engagement in major initiatives for interdisciplinary education of doctoral students on Baltic Sea issues. With her focus on teaching next generation scientists on the ecology of the Baltic Sea, she has laid the knowledge foundations for tackling future environmental problems of the Baltic Sea.
An important area for further research: Eutrophication remains a major environmental problem in the Baltic Sea, but would have been much worse without the ambitious ongoing international efforts to reduce the nutrient loads. Indeed, improvements have been noted in several areas of the Baltic Sea. Research to better quantify nutrient sources and sinks, like that by Maren Voss, is a necessary and crucial support for this important management process.
Contact details of the Prize Recipient:
Prof. Dr. Maren Voss
Professor for Marine Biogeochemistry
Department of Biological Oceanography
Leibniz Institute for Baltic Sea Research Warnemünde, Germany
Click here for short CV of Maren Voss, Prof. Dr.