Aarhus University Seal

Mussel mitigation cultures; mussel growth, environmental quality and site selections (2019)


ECTS credits: 3


Course parameters:

Language: English

Level of course: PhD level, but master students may be permitted

Time of year: summer course 2019, week 34 (18-25 August 2019)

No. of contact hours/hours in total incl. preparation, assignment(s) or the like: 74/81

Capacity limits: 20 students


Objectives of the course:

Mussel mitigation cultures can actively be used to mitigate effects of excess nutrient run-off from land. Mussels possess a significant capacity for clearing the water column of particles and are thereby bounding nutrients in their tissue. Harvest of the farmed mussels will imply a return of the bound nutrients back to land thus reversing eutrophication. In addition, the clearing of the water column increases environmental quality.

There may, on the other hand, be negative effects through increased sedimentation of biodeposits locally below the farms increasing the oxygen consumption and changing the sediment chemistry. Hence, it is important to choose the most appropriate locations for an optimal impact of mussel mitigation cultures on the environment. In the site-selection process of mussel farming, it is also necessary to consider multiple conflicting interests and physical, ecological and legal aspects of the site.

During the course, different modelling methods for estimating mussel growth (bounding of nutrients) and environmental effects in different ecosystems are presented and discussed. The students will work in groups on different case studies and use existing modelling tools to identify optimal sites for location of mussel mitigation cultures. In addition, the concept of Ecosystem Services will be used to identify implications of mussel mitigation cultures on social-ecological systems in coastal areas. Within group exercises, the ecosystem services assessment tool (ESAT) will be applied combined with a stakeholder preference and planning tool to explore how the concept can be used to support decision-making within stakeholder groups.


Learning outcomes and competences:

At the end of the course, the student should be able to:

- further explore the concept mussel mitigation cultures in other areas

- estimate growth potential of mussels by modelling

- estimate the effects on water quality due to mussel mitigation cultures by modelling

- identify areas suitable for mussel mitigation cultures

- use the concept of ecosystem services to assess impacts of mussel mitigation cultures

- apply different tools to support decision-making processes


Compulsory programme:

Sunday: arrival and introduction to course

Monday-Tuesday: Morning lectures and exercise in the afternoon/evening

Wednesday: Excursion to mussel farm and the Danish Shellfish Center

Thursday-Friday: Morning lectures and exercise in the afternoon/evening

Saturday: Presentations and discussion of group projects

Sunday: Departures


Course contents:



Group project on different case studies

Group project presentations

Field trip to mussel farm and the Danish Shellfish Centre



None. Knowledge of mechanistic and statistical modelling is an advantage, but not a prerequisite.


Name of lecturer[s]:

Dr. Marie Maar

Professor Jens Kjerulf Petersen

Professor Mats Lindegarth

Professor Gerald Schernewski

Dr. Lars Kjerulf Petersen

Dr. Slawomir Sagan


Type of course/teaching methods:

Lectures, exercises, group work, dynamic modelling, statistical modelling, ecosystem services assessment tool, field trip



See list below.


Course homepage:



Course assessment:

Active participation during the course

Presentations of scientific papers and exercises

Evaluation of group project



Aarhus University (Department of Bioscience) with support from the Danish Technical University (Danish Shellfish Center), University of Gothenburg and Leibniz-Institute for Baltic Sea Research Warnemünde (IOW) and Institute of Oceanology PAS (IOPAN).


Special comments on this course:

The course is financially supported by the BONUS Optimus project http://www.bonus-optimus.eu/. Hence, accommodation and meals are covered by the project, but travel costs are on the expense of the student.



Sunday 18 August to Sunday 25 August 2019



Rønbjerg Field Station (Limfjorden), Livøvej 141, 9681 Ranum, Denmark



Deadline for registration is 1 May 2019. Information regarding admission will be sent out no later than 8 May 2019.

For registration: mam@bios.au.dk

If you have any questions, please contact Marie Maar, e-mail: mam@bios.au.dk


Literature list:

  • Bergstrom P, Carlsson MS, Lindegarth M, Petersen JK, Lindegarth S, Holmer M (2017) Testing the potential for improving quality of sediments impacted by mussel farms using bioturbating polychaete worms. Aquacult Res 48:161-176
  • Bergström P, Lindegarth S, Lindegarth M (2015) Modeling and predicting the growth of the mussel, Mytilus edulis: implications for planning of aquaculture and eutrophication mitigation. Ecology and Evolution 5:S920-S933
  • Bricker SB, Getchis TL, Chadwick CB, Rose CM, Rose JM (2016) Integration of ecosystem-based models into an existing interactive web-based tool for improved aquaculture decision-making. Aquaculture 453:135-146
  • Ferreira JG, Bricker SB (2016) Goods and services of extensive aquaculture: shellfish culture and nutrient trading. Aquacult Int 24:803-825
  • Gren IM, Lindahl O, Lindqvist M (2009) Values of mussel farming for combating eutrophication: An application to the Baltic Sea. Ecol Eng 35:935-945
  • Lindahl O, Hart R, Hernroth B, Kollberg S, Loo LO, Olrog L, Rehnstam-Holm AS, Svensson J, Svensson S, Syversen U (2005) Improving marine water quality by mussel farming: A profitable solution for Swedish society. Ambio 34:131-138
  • Nielsen P, Cranford PJ, Maar M, Petersen JK (2016) Magnitude, spatial scale and optimization of ecosystem services from a nutrient extraction mussel farm in the eutrophic Skive Fjord, Denmark. Aquaculture Environment Interactions 8:311-329
  • Petersen JK, Hasler B, Timmermann K, Nielsen P, Tørring DB, Larsen MM, Holmer M (2014) Mussels as a tool for mitigation in the marine environment. Mar Pollut Bull 82:137-143
  • Petersen JK, Timmermann K, Carlsson M, Holmer M, Maar M, Lindahl O (2012) Mussel farming can be used as a mitigation tool - A reply. Mar Pollut Bull 64:452-454
  • Schernewski G., Inácio M., Nazemtseva Y. (2018): Expert based ecosystem services assessment in coastal and marine planning and management: A Baltic lagoon case study. Frontiers in Environmental Science, doi: 10.3389/fenvs.2018.00019
  • Schröder T, Stank J, Schernewski G, Krost P (2014) The impact of a mussel farm on water transparency in the Kiel Fjord. Ocean Coast Manage 101:42-52
  • Schumacher J., Schernewski G., Bielecka M., Loizides M.I., Loizidou X.I. (2018) Methodologies to support coastal management - A stakeholder preference and planning tool and its application. Mar. Policy 94: 150-157.
  • Stadmark J, Conley DJ (2011) Mussel farming as a nutrient reduction measure in the Baltic Sea: Consideration of nutrient biogeochemical cycles. Mar Pollut Bull 62:1385-1388
  • Timmermann K, Maar M, Bolding K, Windolf J, Petersen JK (2018) Mussel production as a tool for nutrient mitigation: Environmental effects on basin scale. Submitted
18801 / i43