Last February took place at the Tvärminne Zoological Station the third edition of the Finmari researcher days. Finmari stands for Finnish Marine Research Infrastructure and it is a distributed infrastructure network of field stations, research vessels and multi-purpose icebreakers, laboratory facilities, ferryboxes, fixed measurement platforms and buoys of the Finnish marine research community.
Over two days, marine researchers presented their work with subjects ranging from plastic and noise pollution to climate change and biodiversity.
In the context of the newly launched communication project about the Finnish research stations (#tietaajarakastaa), the talks could be recorded in video. In this post you can see the first video, featuring researcher Pinja Näkki from SYKE, about the fate of microplastics in marine sediments. The rest of the talks will be available here.
Picture 1. (a) 2-D contour plots of dissolved (top) and particulate (bottom) Fe in the water column along the Mustionjoki transect (Stations A– K), operationally defined by filtration at 0.45 µm, June 2015. White circles represent sampling positions (vertical depth resolution = 5 m). (b) Data from “a” plotted against salinity, including trend lines for Fepart (polynomial) and Fediss (logarithmic). Linear conservative mixing lines (CMLs) are drawn between the high- and low-salinity end-member samples for Fepart and Fediss. The inferred dominant processes controlling Fepart along the salinity transect are indicated by the grey bars (T. Jilbert et al. 2018: Impacts of flocculation on the diagenesis of iron).
NEW PAPER! Coastal ecosystems of the Baltic Sea are strongly influenced by inputs of material from rivers. Eutrophication and climate change are altering these inputs, hence there is an urgent need to understand the natural cycling of terrestrial material in estuaries. In a new open access paper in Biogeosciences, Tom Jilbert and colleagues from the Aquatic Biogeochemistry Research Unit (ABRU) studied the effect of riverine inputs of iron on sediment microbial processes in Pojo Bay, an estuary close to TZS. Sediments host rich microbial communities that carry out key ecosystem functions such as the breakdown of organic matter and recycling of nutrients. Because many microbes use iron in their metabolism, the natural input of iron minerals from rivers may be important in regulating the microbial functioning of coastal sediments. Tom’s work shows that dissolved iron in river water precipitates in the estuarine environment via a process known as flocculation, leading to higher rates of microbial iron utilization in nearshore areas. The abundance of iron in coastal sediments could have knock-on effects for other sedimentary processes, including carbon burial and the production of methane.
During spring time when the canopy leaves emerge in deciduous trees in temperate forests, there is a drastic change in light quality reaching the forest understorey. In collaboration with the Canopy Spectral Ecology and Ecophysiology group (CanSEE) at the University of Helsinki, researchers from the University of Rouen (Université de Rouen) visited Lammi Biological station this summer to investigate how this drastic change in light quality reaching the forest floor affects the ecosystem as a whole.
Plants in the understorey utilise light signals as cues to help time when their leaves emerge, when they flower, how to tall to grow, how large to make their leaves, as well as affecting their photosynthesis, leaf pigments and root growth.
Over the last three years the CanSEE group led by Dr Matthew Robson has been characterising the changes in the composition of light that reaches the forest understorey, and examining how different plant species respond to the change in these light signals. However these changes seen above ground are only half the story.
How does this affect below ground processes? The properties of soil in close vicinity to plant roots are modified by a large range of processes that occur during plant growth, which in turn affect the rhizosphere microbiota. Plant roots not only contain compounds such as sugars and amino acids for soil microbiota, but also compounds for defence such as antimicrobials and nematicides. Furthermore, the uptake of ions in the soil by roots can drastically affect the pH of the soil.
Researchers Dr Estelle Forey and Marta Pieristé from the University of Rouen are now beginning to investigate these questions, and in collaboration with CanSEE group, seek to understand how light quality in the forest understorey affects the ecosystem as a whole.
After long term plots either blocking out different light signals were set up in 2016, the two research groups have begun to sample the changes that occur in plants, soil and microfauna when these plots are deprived of different light signals.
A filter blocking out blue light over plants in the forest understorey. These long term plots were set up in 2016, where the plants have been monitored over the course of two years (photo: Marta Pieristé)..Dr Estelle Forey and PhD student Craig Brelsford from CanSEE group taking soil core samples from the plots. These will then be analysed by for the content of the soil, and the composition of mircofauna inside (photo: Marta Pieristé).
The results from this work may be important in understanding how climate change will affect the forest understorey ecosystem. The date of canopy leaf out in spring is advancing at 2.5 days per decade since 1971 in temperate forests due to rising global temperatures. In turn, this means that the changes in light signals due to canopy shade in the forest understorey will occur earlier, and may have cascading effects on understorey species of plants, soil and microfauna.
The eider duck has recently been classified as endangered within the EU (photo: Heikki Eriksson).
A new research initiative at Tvärminne Zoological Station (TZS) brings together long-term research projects and conducts field and laboratory experiments, all in order to understand the function of the Baltic food web and how it is affected by environmental change. The research focuses on a community module consisting of blue mussels, eider ducks and white tailed sea eagles. This module forms a central part of the Baltic ecosystem and contains a keystone species, a mesopredator and a top predator and it links the marine and the terrestrial environments. We investigate the direct and trophically mediated impacts of environmental change within this group of closely interacting species representing three different trophic levels. Special emphasis is put on the trophic interactions surrounding the eider duck and how these affect its population development. The eider populations are in precipitous decline and the species was recently classified as endangered within the EU. We hope to understand what processes are driving the eider populations and to mitigate potential threats.
Blue mussels covering the rocky bottom. The blue mussel is the main food item for eider ducks (photo: Kim Jaatinen).
In 2017 Kim Jaatinen (TZS) and Markus Öst (Åbo Akademi) conducted their traditional fieldwork studying the Tvärminne eider population. This season was especially interesting and worrisome: the research group recorded an all time low in the population’s offspring production. Normally the 12 km wide research area produces between 1000 and 2000 ducklings, but this year only a mere 41 ducklings were seen in the standard duckling survey conducted at the end of June. Predation by sea eagles plays a major role in this low production but also other causes are under investigation.
One more eider female measured, sampled and ready to go (photo: Heikki Eriksson).These less than a day old eider ducklings are ready to go to sea (photo: Heikki Eriksson).
The blue mussel study conducted by Mats Westerbom, Kim Jaatinen and Alf Norkko focuses this year on analysing the effects of climate change on the population dynamics of this species so central to the Baltic ecosystem. In addition to applying new analysis techniques to the long-term data, the group has continued work on monitoring recruitment of young mussels to the population. This year a new monitoring scheme was started, which aims at following spatial and temporal variations in the condition (i.e., meat content) of the mussels.
The findings of this year’s projects will all shed light on the impact we are having on the Baltic Sea and how its ecosystem will be affected. This knowledge may help us mitigate the bad influence we are having on our environment. Stay tuned for upcoming results!
A crushing wave. A typical element in the lives of the eider ducks and the blue mussels (photo: Kim Jaatinen).
Text: Dr. Kim Jaatinen, Tvärminne Zoological Station
Photos: Heikki Eriksson & Kim Jaatinen
Research in the Behavioural Ecology Research Group (Monash University, Australia), led by Associate Professor Bob Wong, focuses on the evolution of animal mating systems and behaviour. We have, for instance, investigated the impacts of environmental change on animal behaviour and the evolutionary process, and how investment in sex influences reproductive strategies and biological diversity.
Members of the Group have had a long association with Tvärminne Zoological Station. In this respect, the Group has also been working in close collaboration with Prof. Kai Lindström (and others) for over a decade on sexual selection and parental care in fish. The work in Tvärminne has involved both field and laboratory-based research investigating the role of environmental factors (e.g. salinity, predation risk, competition, resource quality and density) on male and female mating behaviour. Our work has also included student research, with Australian-based students undertaking experiments on male parental care in sand gobies and sticklebacks.
In 2017, Bob Wong and Dr. Topi Lehtonen completed a field based experiment in Tvärminne, investigating the role of nesting resource quality and male-male competition on patterns of nest colonisation in male sand gobies. The research involved setting up artificial nesting resources (ceramic tiles) in shallow water near Vargskär Island and manipulating both the quality of the resource (large versus small tiles) and the extent of resource aggregation (i.e. a single nesting resource on its own, or two nesting resources in close proximity) and examining the attributes of the males that subsequently settle into those areas. The findings will contribute to our understanding of how resources and resource competition affect settlement patterns in the wild.
Artificial nesting resource (ceramic tile) in shallow water (photo: Topi Lehtonen).Dr. Topi Lehtonen and Associate Professor Bob Wong on a small boat doing a friedsie (photo: Topi Lehtonen).
Associate Professor Bob Wong, Monash University, Australia.
New research from LBS professor Lauri Arvola and colleagues shows that contrary to expectations, Finnish lakes on the whole have not become browner over a 101 year period (1913-2014). This is the first time that a comparison over such a long time period has been made.
The hue of the water has become browner in many lakes, but the opposite is true in others, and many have remained stable.
See this link for the publication:
