Josefin Sagerman, researcher

Josefin Sagerman

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Visiting address Svante Arrhenius väg 20 F, plan 5
Postal address Stockholms universitets Östersjöcentrum 106 91 Stockholm

About me

I am a marine ecologist interested in biodiversity, ecosystem functioning and human impacts on natural systems.


The focus of my research is directed to:

  • Human impacts on seaweed and submerged plant communities (including coastal exploitation and species invasions)
  • Factors affecting the success of non-native primary producers, e.g. competition and plant-herbivore interactions
  • Monitoring of benthic species and habitats
  • Systematic reviews and meta-analysis

Current projects

Coastal exploitation and marine habitats
Vegetation growing on soft substrate in coastal areas constitutes an important living environment for juvenile fish and organisms at the base of the food chain. These shallow vegetated areas are under high pressure from human activities, such as nutrient input from land and boating activities.  Building of marinas, dredging and intense boat traffic results in increased turbidity and turbulence in otherwise wave protected areas. Large amounts of aquatic vegetation have been lost due to human exploitation the last century. I am working with a research synthesis evaluating impacts of boating activities on benthic vegetation, with the aim to estimate the environmental impact from boat traffic compared to other stressors and to explore how much boat traffic different types of vegetation can tolerate.  

Enemy release and non-native seaweeds
Human influence on marine coastal ecosystems has resulted in large scale changes to the abundance and distribution of species, where species introductions constitute an obvious part. Conspicuous non-native seaweeds are affecting local species diversity and altering habitat properties. But little is known of general patterns explaining the success of seaweed invaders. I am working with a research synthesis exploring patterns in how native herbivores discriminate between native and non-native seaweeds as food, and how this may affect the competitiveness of seaweed invaders.

Effects on decomposition of seaweed invaders with different ecological strategies
Decomposition determines the turnover rate of nutrients and the food availability at the base of the extensive detritus based food-web. Non-native primary producers may alter ecosystem functions, such as decomposition in native communities. I am exploring the link between ecophysiological traits of seaweed invaders and decomposition rates to find out how traits that are linked to invasion success directly may impact on native communities.

More information

To have a closer look at my publications, please visit my page at Research Gate

To see my latest posts about systematic reviews and meta-analysis, please visit the Google+ community for “Meta-analysis in Ecology and Evolution”


Sagerman J, Enge S, Pavia H, Wikström SA (2015). Low feeding preference of native herbivores for the successful non-native seaweed Heterosiphonia japonica. Marine Biology 162: 2471-2479.

Sagerman J (2015). Marine seaweed invasions: Impacts and biotic resistance in native ecosystems. ISBN 978-91-7649-176-8, Dept. of ecology, environment and plant sciences, Stockholm University (PhD theses).

Sagerman J, Enge S, Pavia H, Wikström SA (2014). Divergent ecological strategies determine different impacts on community production by two successful non-native seaweeds. Oecologia 175:937-946.

Hansen JP, Sagerman J & Wikström SA (2010). Effects of plant morphology on small-scale distribution of invertebrates. Marine Biology 157: 2143-2155.

Engdahl A & Sagerman J (2008). Basinventering av Svalan och Falkens grund, Bottenviken - Del av utsjöbanksinventeringen 2008. AquaBiota Notes 2008:1 (report).

Last updated: November 15, 2018

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