ABRU is undergoing a transition, as Tom Jilbert is now affiliated at Faculty of Science (Department of Geosciences and Geography). A link to the new group website will follow here shortly. This page lists researchers recently affiliated with ABRU and their current status, as well as former members. Research in the field of Aquatic Biogeochemistry is still active at EcoEnv with several group members remaining at Viikki campus.

Tom Jilbert was Assistant Professor (Tenure Track) within the Ecosystems and Environment Research Program (ECOENV) from 2016-2021. Since September 2021 he is affiliated at Faculty of Science (Department of Geosciences and Geography). He is also Academy of Finland Research Fellow since September 2018. Tom is a member of the Editorial Boards of Chemical Geology and Frontiers in Earth Science and co-ordinates the international symposium on lake restoration Lahti Lakes. He is specialized in the study of sediment biogeochemistry and phosphorus cycling, in particular in eutrophied and low-oxygen aquatic environments.

Tom on Google Scholar, TUHAT and Twitter.


Karoliina Koho was an Academy Research Fellow (2014-2019) and the Principal Investigator in two Academy of Finland funded projects. Her work is focused on the interface of ecology and biogeochemistry, investigating how benthic (micro)organisms influence oxygen dynamics, and nutrient and carbon cycling in sediments. Her research to date has focused on understanding of biogeochemical cycles and ecosystem dynamics in low-oxygen settings, such as oceanic Oxygen Minimum Zones (OMZs), as well as survival strategies of single celled eukaryotes (benthic foraminifera) in these hostile environments. In addition to benthic ecology and biogeochemistry, Karoliina's previous projects have included aspects of paleoenvironmental research and development of foraminiferal paleoindicators, or proxies. These aspects of her research background connect her understanding of modern day aquatic biogeochemistry to long-term elemental cycles on Earth. Since 2019 Karoliina works at BONUS, the joint Baltic Sea research and development programme.

Karoliina on TUHAT.

Eero Asmala was a post-doctoral researcher funded by Academy of Finland from 2018-2021, based at Tvärminne Zoological Station. Since September 2021 Eero is based at the Geological Survey of Finland. His research covers broadly organic matter biogeochemistry in coastal areas. His Academy project focused on short-term variations in river discharge (such as rain events) and their effect on organic matter inputs to coastal areas.

Eero on TUHAT, Google Scholar and Twitter.

Saija Saarni is a post-doctoral researcher funded by Academy of Finland. She was a member of ABRU from 2019-2021 based at Viikki. Since 2021 Saija is affiliated at Univeristy of Turku. Her research interests are to study 1) climatic and anthropogenic forcing of lake sedimentation and catchment erosion, and 2) sedimentary processes of micro plastic litter in aquatic environments. The latter field of interest is also the main focus of her current - Academy of Finland funded - project "BaSeMent": Baltic Sea Monitoring on Microplastic sedimentation processes.

Saija on the Research Portal and Twitter.


Dana Hellemann is a post-doctoral researcher funded by the Walter and Andrée de Nottbeck Foundation, whose background and research interest lie in the field of marine biogeochemistry, with a focus on elemental cycling in coastal systems, biogeochemical responses to anthropogenic pressures, eutrophication dynamics, and, particularly, the nitrogen cycle. In her current project, Dana studies how the specific composition of in situ organic carbon affects benthic nitrate reduction processes in different zones of the Baltic Sea coast along a seasonal cycle from pre- to post-spring bloom conditions. Dana is based both at Viikki campus and Tvärminne Zoological Station.

Dana on TUHAT.

Martijn Hermans is a post-doctoral researcher in the group of Tom Jilbert. Since September 2021 he is affiliated to Faculty of Science (Department of Geosciences and Geography). He is specialised in electromicrobiology and marine biogeochemistry. His past research focused on the impact of cable bacteria and changes in bottom water oxygen concentrations on coastal sediment biogeochemistry. The main impetus of his current study is to implement the coupled sedimentary iron and phosphorus dynamics in relation to bottom water oxygen in the BALTSEM model, which is a coupled physical-biogeochemical model for the whole Baltic Sea. Among many applications, this model expansion can be used to gain a better mechanistic understanding of how the iron-phosphorus feedbacks drive the multidecadal oscillations in Baltic Sea hypoxia. The post-doc project is strongly supported by collaborators, such as Prof. Bo Gustafsson (Baltic Nest Institute, Stockholm University, Baltic Sea Centre) and Prof. Caroline Slomp (Utrecht University). Martijn is funded by the Academy of Finland research fellowship to Tom Jilbert 'Sedimentary trace metals: unlocking the archives of coastal marine hypoxia'.

Iines Salonen is a post-doctoral researcher specialised in microbiology and molecular ecology. In her work, she utilizes molecular approaches based on Next-Generation Sequencing. During her PhD, she explored the use of eDNA metabarcoding in investigating the diversity and interactions of sediment bacterial communities and unicellular eukaryotes such as the foraminifera. In her first postdoc project at ABRU, she focused on environmental monitoring and assessment of the benthic ecosystem, investigating how DNA-based methods could potentially improve or bring added value to existing monitoring practises. Since 2021 Iines is working at the Japan Agency for Marine-Earth Science and Technology JAMSTEC on an Academy of Finland-funded postdoctoral research project. 

Iines on TUHAT.

Mari Joensuu is a PhD student studying sediment erodibility and resuspension in coastal areas of the Baltic Sea. She is specifically interested in the environmental drivers behind the spatial and temporal variability of sediment erodibility in natural environments. She is also a member of the Benthic Ecology Team at Tvärminne Zoological Station.

Mari on TUHAT.

Sami Jokinen is a PhD student studying the long-term development of eutrophication and oxygen deficiency in the coastal northern Baltic Sea. He uses a wide set of sedimentological and geochemical proxies to probe the effects of climatic oscillations and anthropogenic nutrient inputs on bottom water oxygenation. Sami has worked within Karoliina Koho's Academy of Finland project ´Next Generation Tool for Environmental Assessment´ and Tom Jilbert's Academy Research Fellowship´Sedimentary trace metals: unlocking the archives of coastal marine hypoxia´to assess the mechanisms of trace metal sequestration in coastal sediments in the Baltic Sea. Since 2020 Sami works at the Geological Survey of Finland.

Sami on Research Gate.

Soila Silvonen is a PhD student based at Viikki, working with Tom Jilbert on the project 'Optimizing the efficiency of the Kymijärvi hypolimnetic withdrawal filter'. She gained her MSc in limnology and also worked within ABRU as a technical assistant in the 'Next Generation Tool for Environmental Assessment' project. She is especially interested in different anthropogenic impacts on aquatic ecosystems, as well as their management, and lake and coastal restoration. In her PhD, Soila investigates the chemical mechanisms by which the new filter system retains phosphorus, as well as the possible impacts of the system on a nearby wetland. Ultimately, Soila's project aims to determine the viability of hypolimnetic withdrawal and treatment as a restoration measure for larger eutrophic lakes.

Soila on TUHAT.

Mareike Paul is a PhD student studying the mechanisms of trace metal enrichment in the sediments of coastal European seas. Since September 2021 she is affiliated to Faculty of Science (Department of Geosciences and Geography). Mareike's study areas include the Baltic Sea and Swedish West Coast fjords. Each of the study areas are characterized by varying environmental stress (eutrophication – hypoxia – anoxia/euxinia), salinity and anthropogenic impacts, all of which influence the concentration of trace metals in sediments. Although general ideas of sedimentary concentrations of the trace metals and their potential as proxies for redox conditions exist, many details of sedimentary trace metal chemistry and enrichments are still poorly constrained, which limits the use of trace metals as quantitative recorders of (past) hypoxia. Hence, the aim of this project is to shed light on these ongoing problems. The project is strongly supported by collaborators, such as Prof. Caroline Slomp (Utrecht University), the Baltic Bridge collaboration between Stockholm University and Tvärminne Zoological Station, the FINMARI consortium (Baltic Sea), Dr. Helena Filipsson (Lund University) and Prof. Karline Soetaert (Royal Netherlands Institute for Sea Research; NIOZ). Mareike is funded by the Academy of Finland research fellowship to Tom Jilbert ´Sedimentary trace metals: unlocking the archives of coastal marine hypoxia´.

Mareike on TUHAT.

Siqi Zhao is a PhD student based at Viikki, working with Tom Jilbert on the new project `Timescales of recovery from eutrophication in Finnish lakes´, where she is studying sedimentary phosphorus dynamics in eutrophic lakes in the agricultural areas of southern Finland. Siqi is interested in the effect of internal loading of phosphorus on restoration from lake eutrophication, and especially in the recovery timeline. In her PhD work, she will compare the differences of sedimentary phosphorus processes between lakes with varied lake catchment area/lake surface area ratios, and history of nutrient loading. Furthermore, she will build nutrient cycle models for Finnish lakes to predict their development with the decrease of external phosphorus loading in the future. Siqi is a grant researcher funded by the China Scholarship Council.

Susanna Hietanen

Susanna Hietanen was Academy Research Fellow (2013-2018) and leader of the "Nutrient cycles in aquatic ecosystems" group within ABRU. She led the project ´Biogeochemical links between eutrophication and climate change in the Baltic Sea´ and was responsible for ABRU work in the project ´BONUS COCOA: Nutrient cocktails in the coastal zone of the Baltic Sea´. She is a specialist in the aquatic nitrogen cycle, having extensively studied denitrification, anammox, nitrification and DNRA in sediments and water columns both in freshwaters and in the Baltic Sea.

Susanna on Google Scholar, Research Gate and TUHAT.

Petra Tallberg

Adjunct Professor Petra Tallberg is an expert on the biogeochemical cycling of silicon who worked in the "Nutrient cycles in aquatic ecosystems"-group of Susanna Hietanen. She is currently involved in the international research projects “Marine primary producers under thinning ice - past responses and future projections for high Arctic Greenland” (at the Geological Survey of Denmark) and “Promoting phosphorus mobilization in soils using silicon fertilization” (at University of Evora, Portugal). Former projects and research interests include biogenic silica analysis, the Si cycle in the Baltic Sea, silicon-phosphorus interactions, terrestrial Si cycling, diatom sedimentation dynamics, phytoplankton ecology and aquatic food web restoration. She is also active in the field of environmental education.

Jesse Harrison

Jesse Harrison was a postdoctoral researcher working on the Academy of Finland ´Next Generation Tool for Environmental Assessment´ project, focusing on the applications of high-throughput sequencing in benthic monitoring surveys. Previously he worked as a postdoc at the Universities of Vienna (Division of Microbial Ecology) and Edinburgh (UK Centre for Astrobiology), where his research topics included single-cell microbiology and the habitability of extreme ecosystems. Jesse also has a continuing interest in research into the environmental impacts and fate of microplastics. His wider roles have included serving on the European Commission-funded AstRoMap European Astrobiology Roadmap Panel, a Defra Technical Advisory Group focusing on the biodegradability of plastic waste, and collaborating on the NASA BASALT (Biologic Analog Science Associated with Lava Terrains) project.

JP Myllykangas

JP Myllykangas was a PhD student in the project ´Biogeochemical links between climate change and eutrophication in the Baltic Sea´. He studied methane processes in coastal sediments and water column of the Baltic Sea. His research topics ranges from large scale disturbances down to specific processes concerning microbial production and consumption of methane. He was especially interested in estuarine environments and learning what are the main drivers behind spatial and temporal changes in methane processes in these systems and how they connect to eutrophication and climate change.


Myrsini Chronopoulou

Myrsini Chronopoulou was a postdoctoral researcher working on the role of benthic foraminifera and their endobionts in key biogeochemical processes, as well as the application of Next Generation Sequencing as a biomonitoring tool.  Her PhD research (University of Essex) focused on the impact of crude oil on microbial communities and the role of nitrogen fixing bacteria in oil impacted marine environments. During her previous postdoctoral projects (Queen Mary, University of London & University of Essex) she studied important aspects of the nitrogen cycle (e.g. production of nitrous oxide and nitrogen gas) and the carbon cycle (methanogenesis and methane oxidation) in the ocean, as well as in freshwater ecosystems. Her research is characterised by a dual approach, a) looking at the processes occurring in the ecosystem by applying chemical and stable isotope analysis and, b) targeting the microbial communities involved in these processes by in-depth molecular analysis (e.g. high throughput sequencing techniques) and subsequent bioinformatics/data analysis.

Antti Rissanen

Antti Rissanen joined ABRU for the month of November 2018 to consolidate collaborations with Tom Jilbert and JP Myllykangas, studying methane-related processes in lake and estuarine sediments. Rissanen has previously worked as an Academy of Finland postdoctoral researcher at Tampere University of Technology and as a postdoctoral researcher at University of Eastern Finland and University of Jyväskylä. He is specialized in the microbiology of sediments and water columns.

Pirita Anttila

Pirita Anttila was a University of Helsinki MSc student working on her thesis “Effects of heavy metals on benthic macrofaunal communities” within the larger project ´Next Generation Tool for Environmental Assessment´. She focused on identifying species in sediment macrofaunal samples and combining the results with sediment heavy metal and organic content analysis results.

Gunnar Jakobs

Gunnar Jakobs was a post-doctoral guest researcher in Susanna Hietanen's team. He is a specialist in the pelagic methane turnover in the central Baltic Sea, including the determination of methane oxidation rates using 14C labeling experiments, analysis of dissolved methane in seawater and identification of microorganisms involved. He has studied the seasonal and spatial variability in water column methane distribution as well as the methanotrophic response to changing environmental conditions. In addition he has investigated the links between denitrification and methanotrophic processes in the marine environment using bioreactor based enrichment experiments. He currently works at Center for Nuclear Technologies, Technical University of Denmark.

Anni Jylhä-Vuorio

Anni Jylhä-Vuorio worked as a technical assistant in 2015 in Susanna Hietanen's project ´Biogeochemical links between eutrophication and climate change´, in 2016 for Tom Jilbert within the project ´Phosphorus burial in Lake Vesijärvi´, and in 2017 with Karoliina Koho within the project ´Next Generation Tool for Environmental Assessment´.

Peter Petros

Peter Petros completed a research project at ABRU in 2017 studying the particle size dynamics of suspended particulate matter (SPM) in Pohjanpitäjänlahti estuary using data gathered from a LISST-100X particle size analyzer. Peter will return to his native Australia to graduate from his MCEng at the University of Melbourne before coming back to Finland to begin a PhD position studying drained peatland hydrology, up north at the University of Oulu.

Rosa Tiihonen

Rosa Tiihonen completed her MSc research project in ABRU in 2016 studying the factors conrolling the distribution of iron and manganese in coastal sediments of the Gulf of Finland (supervisors Tom Jilbert and Susanna Hietanen). She then worked with Karoliina Koho as a technical assistant in the project ´Next Generation Tool for Environmental Assessment´.

Luukas Lintumäki

Luukas Lintumäki is an MSc student specializing in hydrogeology and environmental geology. He is carrying out his MSc thesis work with Tom Jilbert, within the project ´Iron and manganese cycling in boreal estuaries´. The project is part of the Baltic Bridge collaboration between Tvärminne Zoological Station and Stockholm University. The goal of Luukas' thesis is to determine how fluxes of organic matter and iron to coastal sediments of the Gulf of Finland have changed due to human activties in recent centuries, and their impact on biogeochemical processes in sediments. Previously in his BSc thesis, Luukas has studied eutrophication mechanisms and remediation techniques in lakes. He is particularly interested in human impact and restoration of aquatic environments.