We are in particular interested in disturbance ecology and threats to biodiversity, and its ecological consequences. Therefore we are broadly interested in exploring the value of biodiversity for ecosystem multifunctionality and the mechanisms important for its maintenance. Different aspects of our research are briefly represented within the research projects;
The role of the coastal zone as a filter for nutrients from land to the sea is largely an unknown black box. The BONUS-project COCOA will analyse the pathways of nutrients in the coastal zones of the Baltic Sea by quantifying the role of bacteria, phytoplankton, benthic microalgae, seagrasses, macroalgae and fauna in transforming and accumulating nutrients in four different types of coastal ecosystems (learning sites: lagoons, river-dominated estuaries, embayments, and archipelagos). In the area around TZS, we concentrate on the links between biodiversity and nutrient cycling.
People: Alf Norkko, Anna Villnäs, Johanna Gammal, Mari Joensuu, Guillaume Bernard, Joanna Norkko (TZS), Marie Järnström, Erik Bonsdorff (Åbo Akademi), and partners in Finland, Denmark, Sweden, Germany, Lithuania, Poland, Russia, and the Netherlands.
Seagrass functional ecology (1.1.2015-31.08.2019)
Seagrasses and other aquatic plants are foundation species that maintain biodiversity and modify the abiotic and biotic environment including primary and secondary production. They form vast underwater meadows that can contain up to 8-9 co-occurring plant species. Our aim is to look at how the diversity of aquatic plant species and their traits i.e. functional diversity, influence ecosystem processes such as primary production along gradients in salinity and wave exposure and the resilience and recovery of benthic vegetated habitats. We investigate the link between aquatic plant traits and ecosystem functioning in the brackish-water Baltic Sea and along the coast of Western Australia. The project outcome is to discern how diverse temperate meadows maintain ecosystem functioning locally in different habitats and in geographically contrasting regions.
People: Camilla Gustafsson, Charlotte Angove, Laura Kauppi, Alf Norkko (TZS), Gary Kendrick and research team (University of Western Australia), Johan Eklöf and research team, Tiina Salo (Stockholm University)
The breathing seascape: resolving ecosystem metabolism and habitat-function relationships across coastal habitats (1.9.2016 -31.08.2020)
Coastal ecosystems are exceptionally diverse and productive environments that maintain vital ecosystem functions and services. These ecosystems are, however, under threat from eutrophication, pollution, overfishing and construction. In order to manage the ecosystems wisely, we need to advance our understanding of the role of biodiversity for ecosystem functioning and metabolism. We use novel instruments (Aquatic Eddy Covariance), which for the first time allows us to measure oxygen production and consumption in different key habitats of the Baltic Sea, such as seagrass meadows, mussel beds, bladder wrack belts, bare sand and mud. The measurements can then be linked to the biodiversity and nutrient cycling in these different habitats. Using habitat maps from the national underwater mapping program VELMU, we will scale up our findings to the ecosystem level, i.e. to the scale of societal relevance and management.
People: Alf Norkko, Karl Attard, Iván Rodil and the rest of the benthic ecology team (TZS), Ronnie Glud (University of Southern Denmark)
Living at the edge (1.1.2017 – 31.12.2020)
We are studying population ecology of blue mussels from the perspective of species distribution margins. Species living at the edge of their distribution face a number of challenges that differ from those they face in their distribution centers. With ongoing large-scale changes in the environment, including global climate change, understanding range ecology is becoming increasingly important. We are trying to understand the factors that structure Baltic blue mussels and how changes in blue mussel beds affect the wider coastal community that is dependent on them. We are therefore looking at the links between blue mussels and fish and between blue mussels and eider ducks.
People: Mats Westerbom (TZS), Kim Jaatinen (Luonnon- ja riistanhoitosäätiö), Mikael Kilpi (TZS), Olli Mustonen (Metsähallitus), Alf Norkko (TZS)
Collaboration: Patrik Kraufvelin (SLU), Baltic Bridge
Baltic Sea eutrophication: the effects of increasing accumulations of drifting algal detritus on the functioning of shallow coastal habitats (1.1.2017–31.12.2020)
We study the effects of increasing accumulations of macroalgal detritus on the functioning of coastal habitats. An excess of ephemeral macroalgae and drifting detritus accumulations due to eutrophication can influence almost all levels of ecology, from species interactions to productivity, food-web stability and population dynamics. The goal of the project is to examine how detritus source dynamics might affect benthic communities, oxygen metabolism and the composition of carbon in coastal areas. We will assess the relative importance of the organic carbon derived from primary producers and from detritus into the coastal food-web using stable isotopes (δ13C, δ15N and δ34S). The project is expected to (a) deliver significant advances with regards to an understanding of the ecological role of increasing algal detritus on the functioning of shallow habitats, and (b) provide new insights into the fate of organic carbon production in coastal ecosystems.
People: Iván F. Rodil, T.I. Kahma, Alf Norkko, Christoph Humborg (Baltic Sea Centre, Stockholm University)
Diversity strikes back: Does trait diversity enhance resilience in aquatic plant and faunal ecosystems (2017-2022)
Diverse communities are hypothesized to be able to maintain functioning during environmental disturbance because of species redundancy, where more resistant species can step up and continuously maintain functioning when more sensitive species are lost. Despite increasing numbers of studies on plant functional traits and ecosystem processes in the terrestrial realm, analogous studies in marine environments and particularly seagrasses and other aquatic plants are very few although humans heavily depend on seagrass ecosystems for many goods and services. The infaunal assemblages associated with aquatic plant communities often differ in species composition and densities compared to bare sediment, and contribute to important ecosystem functions, such as provision of nutrients for primary production. The main aim of this project is to explore how the functional diversity of aquatic plants affects the resilience of benthic vegetated habitats. Due to the high species and trait diversity of the aquatic plant communities in the northern Baltic Sea they provide an excellent model system to study how trait diversity affects community resilience. We investigate this in a long-term field experiment, where we follow the recovery of vegetation and the associated faunal communities after a disturbance (simulated drift algal coverage) for five years.
People: Camilla Gustafsson (TZS), Tiina Salo (Stockholm University), Laura Kauppi (TZS)
Chasing a moving target: From wriggling worms in the warming mud to ecosystem-level effects and management of our valuable seas (1.1.2019-31.12.2020)
Soft bottoms and their macrofaunal communities have an invaluable importance for coastal ecosystem functioning through their role in nutrient cycling. Management decisions conserving these valuable ecosystems are based on model predictions of key ecosystem processes and services. Bioturbation performed by benthic fauna in aquatic environments is one of these key processes regulating nutrient retention and release, and oxygenation of the sea floor. Changes in the structure of the macrofauna communities as well as changes in the environment affect the outcome of bioturbation, but our understanding of the underlying mechanistic processes and their context-dependency remains limited. Building on the strong background of observational data, the main objective of this project is to provide mechanistic understanding of the bioturbation processes and the relative importance of factors driving these processes underlying the functioning of seafloor ecosystems. The experimental results will be further used to couple the numerical model of benthic fauna with that of biogeochemical cycling.
People: Laura Kauppi (TZS), Bo Gustafsson (Stockholm University), Guillaume Bernard (CNRS/University of Bordeaux), Joanna Norkko (TZS), Alf Norkko (TZS)
The importance of biodiversity for coastal ecosystems services - consequences of environmental change (1.1.2017 -> )
Coastal marine ecosystems with diverse and healthy communities sustain a wide range of important ecosystem services including oxygen production, nutrient cycling and water filtration. However, these ecosystems are increasingly affected by environmental stressors such as eutrophication and global warming. The goals of this project are to a) increase our understanding regarding what ecosystem services our coastal environments provide and b) explore how environmental change alters the provision of these services. This will be achieved by building further on existing monitoring data across local, regional and a Baltic Sea-wide scale.
People: Anna Villnäs, Alf Norkko
Funding: Sophie von Julins Stiftelse
Elemental stoichiometry of benthic invertebrates as predictor of biogeochemical cycles (1.1.2019-31.12.2021)
What is the role of benthic faunal carbon and nutrient pools in the coastal ecosystem? This project will provide new information regarding carbon (C) : nitrogen (N): phosphorous (P) content ratios and allometric traits of important benthic species. By performing field sampling over temporal and spatial scales, the project will provide novel insight into the intra- and interspecific variability in nutrient stoichiometry of macrobenthic species in relation to available food sources (as revealed by stable isotope analysis) and environmental conditions. The information will be used to quantify the contribution of benthic communities to sediment nutrient storage and recycling rates over temporal and spatial scales, by utilizing existing, large-scale monitoring data from the Baltic Sea.
People & Collaborators: Anna Villnäs (PI), Saara Mäkelin, Aleksandra Lewandowska, Iván Franco Rodil (TZS), Agnes Karlsson, Christoph Humborg (Stockholm University), Michael Vanni (Miami University).
Assessing the role of biodiversity in maintaining coastal ecosystem health in the Anthropocene (04.2019-03.2021)
With globally accelerating rates of species loss, it is imperative we more fully understand the role of biodiversity in maintaining ecosystem function. Ecosystem functions are the ‘jobs’ that are performed by particular species that contribute to ecosystem service delivery (i.e. the benefits humans derive). A simplified approach assumes that within groups of species that do the same job, some are potentially redundant, and this redundancy should buffer (or provide resilience) against some level of species loss. However, recent research has highlighted that there are multiple other factors that determine resilience to human induced species loss beyond the degree of redundancy; including individual species traits that are tolerant to stress, and population connectivity in the landscape. Using field experiments, this project will investigate the attributes that make seafloor macrofaunal communities resilient to disturbances at different spatial and temporal scales (e.g. patch-scale fishing disturbance vs. landscape-scale coastal eutrophication). A key part of the project is to explore the resilience attributes that are important under both high and low scenarios of biodiversity (Baltic Sea where seafloor biodiversity is low and anthropogenic stresses are high vs. New Zealand where biodiversity is high). This research will shed new light on how key elements of biodiversity may respond to future environmental change, enabling a practical way of assessing of societally important coastal ecosystems.
People: Rebecca Gladstone-Gallagher (University of Auckland, New Zealand)