PhD Course: Mussel mitigation cultures; mussel growth, environmental quality and site selections 

Registration for the course has ended, if you would like to learn more or join the course, contact Dr. Marie Maar  (


8 April 2019

Conference on Mussel Cultivation in the Baltic Sea

Nearly 40 experts from science, administration, NGOs and industry met in Warnemünde on 19.3.2019 and discussed the current situation of mussel farms for water quality improvement in the Baltic Sea. Based on current results from research farms in Mecklenburg-Western Pomerania (Wieker Bodden / Greifswalder Bodden), Schleswig-Holstein (Kiel Bay) and Denmark (Mariager Fjord), ecological aspects such as the growth behavior of mussels, their effects on the sediment and the realized nutrient reduction after harvesting were discussed. What is not yet possible in Germany can already be applied in Denmark where mussel farms are regarded as a recognised measure for nutrient reduction and can help to achieve the objectives of the Water Framework Directive. The careful selection of mussel farm sites was discussed as being the most important criterion to be able to comply with the prohibition of deterioration. Undisputed were the ecosystem services associated with shellfish. However, these would have to be better publicised in order to increase the acceptance of mussel farms. At the end of the event, possibilities for financing ecosystem services were presented.

The event was realized as part of the projects Baltic Blue Growth, BONUS OPTIMUS and LiveLagoons and for the first time, made it possible to have an information exchange between relevant German authorities in Mecklenburg-Vorpommern and Schleswig-Holstein. Organizers were EUCC – The Coastal Union Germany (EUCC-D), Ministry of Energy, Agriculture, the Environment, Nature and Digitalization Schleswig-Holstein, Dep. 2: Agriculture, Sanitary Consumer Protection and Fisheries and Leibniz-Institute for Baltic Sea Research Warnemuende.


The presentations will be available shortly at the conference website:


15 March 2019

Next stakeholder meeting and conference in Warnemuende, Germany

On 19th March 2019 the second OPTIMUS stakeholder meeting will take place in Warnemuende, Germany. It will focus on the mussel growing season 2018 and the results of the two mussel research plants in low saline waters of Greifswalder Bodden and Wieker Bodden installed within BONUS Optimus. The results will be compared with other farms in Germany and the Baltic Sea. Therefore, the event will cooperate with the Interreg project Baltic Blue Growth that will be finished in April 2019.
The event will give a broad overview about the situation of Baltic Sea mussel farming in Sweden, Denmark and Germany enabling intensive discussions about transferability and future prospects. It is organized by EUCC – The Coastal Union Germany (EUCC-D), Ministry of Energy, Agriculture, the Environment, Nature and Digitalization Schleswig-Holstein, Dep. 2: Agriculture, Sanitary Consumer Protection and Fisheries and Leibniz-Institute for Baltic Sea Research Warnemuende.

Date: 19.03.2019

Location: Leibniz-Institute for Baltic Sea Research Warnemuende, Seestr. 15, D-18119 Rostock (Main Hall)




25 February 2019

Final field campaign monitoring the benthic impacts of Mitigation Mussel Cultivation

The fourth and final campaign in As Vig, Denmark, evaluating benthic impacts of a mitigation mussel farm, has wrapped up. Over the past 19 months, the University of Gothenburg and DTU Danish Shellfish Center have conducted four field campaigns with Gothenburg's benthic lander systems to characterize chemical fluxes in the sediments within a mitigation farm and at a reference position in the southern Kattegat. Several biophysical processes are expected to influence sedimentation processes around mussel farms, including mussel filtration and egestion of organic matter, and the hydrodynamic influence of a submerged canopy on suspended material. Modification of ambient sedimentation processes can result in modified processes regulating benthic nutrient cycling. As mitigation farms intend to extract nutrients from the environment, it is important to detail associated effects within the environment that may impact the fate of nutrients in a comprehensive manner. These campaigns have captured valuable data sets to quantify and describe many of these processes in situ, such as denitrification, dissimilatory nitrate reduction to ammonium, methanogenesis, oxygen consumption, and sedimentation rates. Sediment sampling during the campaigns is assessing porosity, grain size, presence of infauna, pore water nutrient concentrations, and algal pigment composition of microphytobenthos. Current magnitude and direction of the water column was monitored within the farm and at the reference position for the duration of the campaigns.

The UGOT lander team (left to right): Per Bergström, Mikhail Yurievich Kononets, Astrid Hylén, and Anna Stedt 

The 'Big' benthic lander, in operation at the sea floor

The working boat for the campaigns, Thor P

Happy members of the campaign team on the final day with the 'small' lander. Astrid Hylén is not pictured but was present.

Skipper Hans Rudin, Hjarnø Havbrug

05 September 2018

Danish stakeholder workshop on mussel mitigation cultures in Skive Fjord

The mussel mitigation concept of removing nutrients was introduced to various stakeholders from politics, business, property owners and several organizations of recreational activities at the Danish workshop on the 5th of September 2018. Mussel farming, the concept of mussel mitigation farming, legislation issues and the potential and perspectives of mussel mitigation cultures were presented and lively debated.

During the groupwork and the following presentations the workshop participants were invited to share their knowledge, concerns and suggestions regarding mussel mitigation farming in Skive Fjord. A general consensus was the need for identifying different areas of interests to stakeholders to avoid conflicting uses of the sea and shoreline.

The workshop was organized by DTU Aqua in co-operation with the Department of Environmental Science at University of Århus.


31 May 2018

Test of socio-economic survey at the German case study

On May 31st 2018, the EUCC-D project team travelled to Alt Reddevitz, a small village located in the eastern part of Rügen Island, Germany. This coastal area is a popular summerhouse destination surrounding the Greifswald Bay, where the project mussel farm was installed in April 2017.

The purpose of this trip was to test the survey about public perception and social acceptance of the mussel farm. The actual survey will be carried out between July and September 2018 and will be directed at tourists, inhabitants and holiday house owners within the case study area Hagenschen Wiek

10-12 April 2018

2018 Annual Meeting

OPTIMUS project members met this April in Warnemünde, Germany for a series of presentations and discussions on progress over the past year, as well as planning and organization for activities in 2018-2019. WP leaders presented initial findings to project partners and formalized coordinated actions for the coming mussel settlement and growth season. OPTIMUS as an integrated project, and individual WPs were described to the independent advisory board, with a discussion panel. All participants were provided an excursion to the test farm site in Greifswald Bay. Project members are grateful to the Leibniz-Institute for Baltic Sea Research for hosting this year's annual meeting and look forward to reconvening at IOPAN in 2019.

OPTIMUS project team

Excursion on Greifswald Bay

Different settling material was presented during the excursion

Excursion on Greifswald Bay

Test farm in Greifswald Bay


23 January 2018

First German stakeholder workshop -

Lively debate about mussel farming during first German stakeholder meeting


The idea behind mussel farming for nutrient removal was introduced to various stakeholders from politics, tourism, business, science and environmental protection during our first German workshop on the 23rd of January 2018. Site selection processes, installation challenges and first growth results in the Greifswald Bay were presented and lively debated.

Workshop participants were invited to share their knowledge and to “flag” potential further locations for internal nutrient reduction measures in German coastal waters: Blue flags for mussel farms, green for floating plant islands, yellow for mechanical measures such as sediment dredging, red for chemical measures such as phosphorus precipitation with aluminum and white flags at locations where no internal measures should take place. In one point, all participants agreed: Chemical measures in coastal zones have no acceptance so far.

The workshop was organized by the Coastal Union Germany in co-operation with the Leibniz Institute for Baltic Sea Research Warnemünde and the South Baltic project LiveLagoons.


23 January 2018

First German stakeholder workshop

On 23rd January 2018 the first BONUS OPTIMUS workshop about the case study site Greifswald Bay will take place in Stralsund. The workshop will be organized by EUCC - The Coastal Union Germany in cooperation with the Leibniz-Institute for Baltic Sea Research Warnemuende. Stakeholders from research, public authorities, municipalities, economy (tourism and fishery) and NGOs are invited to discuss the potentials of mussel cultivation for nutrient removal and water quality improvement. The respective project partners will present the outcomes of the site selection process and of the first growing season.

More information about workshop and agenda, click here





View BONUS OPTIMUS news from 2017