BIVALVE FARMING, PROCESSING & PRODUCTS
Developing new value chains in coastal communities, mitigating eutrophication and enhancing aquatic ecosystems
Embracing the full potential of bivalves
By fostering sustainable, innovative practices, we promote bivalve farming (e.g., mussels and oysters) as a catalyst to reduce eutrophication, increase the clarity of waters, and also to provide a reliable source of sustainable protein for both human consumption and animal feed. Furthermore, the versatile bivalve shells can be a valuable raw material for fertiliser, paint, construction materials, and numerous other applications.
Bivalves can realise a unique circular system that can bring legacy nutrients from the sea and back to the land. SUBMARINER Network is promoting the development of bivalves farming, processing, and product and ecosystem services in the Baltic Sea Region to make these benefits a reality.
Discover our bivalve projects
Our projects are advancing bivalve farming and harvesting techniques and supporting businesses to deliver market-ready products
Report on the mussel hygienization process
Animal by-products (ABP), here defined as dead animals and body parts involved in commercial activities that are not intended for
COOL BLUE Baltic
Investing in the mussel value chain
The full potential of bivalve farming, processing, and product development is currently hindered by outdated legislation and an underdeveloped market. Further, large-scale bivalve farming is limited by insufficient infrastructure and the absence of specialized technology. By investing in these resources, we can unlock the benefits of bivalves farming in the Baltic Sea.
It is realistic to envision a future where annual harvests of bivalves in the Baltic are in the tens of thousands of tons, delivering significant economic and environmental benefits.
Together, through our projects and members we are seizing the opportunity to tackle these challenges and to ensure that the full potential of bivalves can be realised.
Bivalve resources hub
Our specialists have put together a collection of publications, additional relevant projects, tools, and resources on the topic of bivalve farming, processing and products
Latest bivalve news
Launching OCCAM: A New EU Project to Future-Proof European Aquaculture Against Climate Change
Berlin, May 19, 2025 – May 1 marked the official
Winners of the Baltic MUPPETS Innovation Call
Following a competitive evaluation, Baltic MUPPETS selected two companies to
The Baltic MUPPETS Innovation Call is open!
Are you an innovator ready to help shape the future
Report on the mussel hygienization process
Animal by-products (ABP), here defined as dead animals and body
Charting Progress: Baltic MUPPETS at the One-Year Mark
Mussel Farming in the Baltic Sea: Estonia
Mussel Farming in the Baltic Sea: Sweden
Mussel Farming in the Baltic Sea: Germany
Baltic Sea Mussels: The future of pet food?
Connecting the Blue Sector: BlueBioMatch
Still have questions? We have answers
Is large-scale mussel farming in the Baltic Sea possible?
Currently hundreds of tons of mussels can be harvested in the Baltic Sea, but there is potential for much more. According to a Danish report, there is a biological potential to produce 300.000 tons of mussels annually in Danish coastal areas, a large part within the western Baltic Sea. Preliminary project results show that there is great biological potential for large-scale mussel farming also in the Baltic Proper, despite lower salinity levels. A total harvest of some ten thousand tons of mussels annually from the Baltic Proper could be realistic in the future.
However, the biological potential of mussel harvest is currently limited by factors that include outdated legislation and an underdeveloped market for the mussels farmed. Large-scale mussel farming also needs infrastructure, such as specially equipped boats and processing plants. Another pressing issue is technology, as most mussel-farming techniques that are used today only work in sheltered waters. In these waters there are typically many conflicting interests. Lack of space has been mentioned as an argument against large-scale mussel farming, but technical development could enable much larger areas in the Baltic Sea for mussel-farming. Hence, large-scale mussel farming in the Baltic Sea is potentially possible, if questions of technology and economy were to be solved.
How large do mussel farms have to be to efficiently reduce eutrophication?
In the SUBMARINER Compendium, authors estimated that if Sweden harvested 9000 tons of mussels every year, this would contribute to 2-3 % of its total target of nutrient reduction set in the Baltic Sea Action Plan. This might not sound as too much, but if all countries around the Baltic Sea harvested similar amounts, it would ultimately add up. Large-scale mussel farming also looks promising if compared to many suggested land-based measures aimed to reduce nutrient inflow. Although agricultural measures can be inexpensive, there is often a lack of waste land or buffer zones between arable land and the coastline and/or steams. Buffer zones are important to stop nutrients leaking from the agricultural land into the sea as they act as nutrient traps. If there are few such buffer zones available, the costs for land-based measures will be very high. Larger constructions that such as wetlands are also regulatory complicated and there are often many stakeholders involved. Industrial measures such as modernizing wastewater treatment plants are easier in terms of regulation and ownership but considerably more expensive per kilo of phosphorous than agricultural measures, particularly when going from 95-96 % to 98-99% uptake of phosphorous from the water.
Measure in the BSR | Reported N removal costs in €/kg N | Reported P removal costs in €/kg P |
Mussel farming without sales | 10 – 64 | 150 – 900 |
Agricultural measures | 0 – 150 | 0 – 10200 |
Livestock reductions | 6 – 842 | 112 – 5895 |
Wastewater treatment upgrades | 11 – 136 | 39 – 600 |
Wetlands | 2 – 93 | 396 – 1518 |
The table above illustrates the cost effectiveness of different methods for reducing nitrogen and phosphorous in the Baltic Sea Region. Looking at this table it becomes clear that mussel farming can under circumstances be much more cost-effective than many other eutrophication counteracting measures. Of course, these figures depend on location and in which country the mussels will be harvested, and thus can vary greatly. The reported cost figures for all measures also vary greatly in the literature, so the listed values can only be seen as a rough estimation. Reliable values for the costs of mussel farming will be generated by the project team.
However, the biological potential of mussel harvest is currently limited by factors that include outdated legislation and an underdeveloped market for the mussels farmed. Large-scale mussel farming also needs infrastructure, such as specially equipped boats and processing plants. Another pressing issue is technology, as most mussel-farming techniques that are used today only work in sheltered waters. In these waters there are typically many conflicting interests. Lack of space has been mentioned as an argument against large-scale mussel farming, but technical development could enable much larger areas in the Baltic Sea for mussel-farming. Hence, large-scale mussel farming in the Baltic Sea is potentially possible, if questions of technology and economy were to be solved.
What are the potential negative impacts of mussel farming on the ecosystem in the Baltic Sea?
Mussels function as efficient biological filters, purifying water masses from phytoplankton and other particulate matter. The filtration makes the water clearer and the increase in water transparency and underwater light conditions may in turn promote plant growth on the seabed (benthos). Mussels and their associated fauna that may drop from the farm enhance the food availability for predators and scavengers close to the sea bed.
However, the increased sedimentation of biodeposits (especially faeces) underneath a mussel farm can locally have a negative impact on the benthos if the mussel farm is placed in a coastal area with slow water currents and bad oxygen conditions. The organic enrichment of the underlying seafloor may lead to hypoxic conditions, releasing nutrients from the impacted sediments into the water. Studies have so far shown that any adverse effects have been restricted to the immediate vicinity of the mussel farms. If a location with well-oxygenated sediments is chosen, negative effects of mussel farming can probably be avoided or reduced.
Buoys and other parts of mussel farm equipment can be disconnected and might cause a local litter problem. The mussel farm equipment such as anchor blocks may have a local effect on the ecosystem. Some experts regard the creation of a new habitat and modification of naturally occurring zoobenthos communities as negative aspect of the mussel farming (locally decreased populations of suspension-feeders and increased deposit-feeders). Nevertheless, the total environmental effect is rather positive because bottom structures such as anchor blocks may provide a surface area for organisms that are normally not found on soft bottoms, where mussel farming often is practiced. Moreover, mussels growing in a suspended culture can create favourable habitats for other invertebrates, fishes and birds. Species diversity and abundance are therefore higher near mussel farms.
