OCCAM aims to develop simple, scalable, and climate-resilient solutions for European aquaculture by piloting innovative adaptation and mitigation measures that enhance environmental sustainability, reduce emissions, and strengthen the sector’s capacity to respond to climate change.
Solution:
Species: Carp
Country: Poland
System: Pond
Case Study Lead: ICR (Industry) and ZUT (Research)
Description: Traditional common carp farming in earthen ponds plays an important role in rural landscapes, offering valuable ecosystem services such as biodiversity support, organic matter storage, and water retention. These ponds are closely connected to their natural surroundings—river catchments, agricultural land, and rural communities.
However, carp farming is highly vulnerable to external factors like changing precipitation patterns, water quality, and extreme weather events. With limited data available for this type of system, it’s crucial to better understand how climate variability affects water availability, overall farm performance, and nutrient release to the environment.
To address this, Case Study 1 (CS1) is developing two key solutions:
Together, these tools will help carp farmers build greater resilience to climate change while protecting surrounding freshwater ecosystems.
Solution:
Species: Rainbow trout
Country: Spain
System: Flow-through & RAS
Case Study Lead: CAVIAR PIRINEA (Industry) and CSIC (Research)
Description: In recent years, rainbow trout farming has faced important challenges due to climate change—particularly prolonged droughts and high temperatures. These conditions reduce water quality and availability, compromise fish welfare, enhance susceptibility to diseases, and can lead to lower production yields in trout farms.
Case Study 2 (CS2) is focused on developing innovative solutions to improve the resilience and productivity of rainbow trout farming in the face of these pressures.
Solution 2A – Selective breeding to improve rainbow trout resilience to heat stress
To help fish better cope with rising temperatures, CS2 is transferring knowledge of selective breeding techniques to enhance thermal resilience. By focusing on genetic markers linked to heat tolerance, researchers are identifying and producing trout lines that are naturally better adapted to warmer water temperatures.
This work takes place at both experimental facilities and commercial farms, helping to translate lab findings into practical improvements for fish producers.
Solution 2B – RAS adaptation of rainbow trout from fresh to brackish water
Rainbow trout can live their whole life in freshwater or spend part of their cycle in seawater. CS2 assesses trout growth and health under various salinity conditions to facilitate the potential adaptation from fresh to brackish water (a mix of fresh and seawater) under real farm conditions. In this way, CS2 is exploring Recirculating Aquaculture Systems (RAS) as a technique to use brackish water (a mix of fresh and seawater) as a sustainable alternative for land-based trout farming in coastal areas nearby.
Thanks to these solutions, rainbow trout land-based farming and its resilience to climate extremes can be secured, offering new opportunities in productive diversification and innovation.
Solution: Solution 3 – Decision support tool (DST) for sea lice management
Species: Salmon
Country: Faroe Islands
System: Marine Cage
Case Study Lead: Hidden (industry), FISK (natural science), SJO (social science), Avrik (ICT)
Description: Sea lice are currently the main obstacle to increasing production in marine salmon aquaculture across Europe. Treatments for sea lice are also one of the largest contributors to fish mortality and a major factor in the industry’s carbon footprint. As ocean temperatures rise due to climate change, sea lice are expected to become an even greater challenge, with faster development rates, increased egg production, and higher infection pressure.
Current models used to guide sea lice management are helpful at the regional level but fall short when applied to individual farms. They are unable to accurately simulate future scenarios that involve changes in climate, farm locations, or production practices, limiting their practical use for producers.
To address this, Case Study 3 (CS3) is developing:
Solution 3 – Decision support tool (DST) for sea lice management: This tool combines a sea lice population model—already used by the Faroese salmon industry—with a hydrodynamic particle tracking system and is further integrated into climate models. This enables realistic simulations of how lice larvae move and develop under changing environmental conditions.
The Faroe Islands provide an ideal test case due to the limited number of farms and consistent third-party sea lice data, allowing for accurate model validation.
With this DST, salmon farmers will be able to optimise operations by evaluating farm location, stocking density, production cycle length, and timing—all while accounting for environmental change. In parallel, the tool will support policymakers in setting more effective sea lice thresholds and improving marine spatial planning.
This solution offers a practical, science-based approach to controlling sea lice sustainably in a warming world.
Solution: Solution 4 – Pyrolysis process for aquaculture sludge
Species: Salmon
Country: Iceland
System: Recirculating Aquaculture System
Case Study Lead: Samher (industry), Matis (research)
Description: Land-based farming of finfish—particularly salmon—is expanding rapidly as an alternative to marine aquaculture. While growth at sea is constrained by regulations and environmental challenges, land-based systems offer greater control over water quality, temperature, and disease exposure, enhancing fish welfare and production security. They also align with consumer demand for sustainable, high-quality seafood produced with minimal environmental impact.
However, one of the critical challenges facing land-based aquaculture is the management of fish sludge—a by-product made up of fish waste and uneaten feed. Current disposal methods, such as landfill, are neither sustainable nor environmentally friendly. For example, in Iceland alone, projected land-based salmon production could generate up to 300,000 tons of sludge annually, highlighting the urgent need for circular and scalable solutions.
To address this, Case Study 4 (CS4) is developing:
Solution 4 — Pyrolysis process for aquaculture sludge: a carbon-rich material that can be used as a soil improver and fertilizer. This innovative solution not only offers a sustainable way to manage sludge, but also helps sequester carbon and reduce reliance on imported chemical and fossil-based fertilizers.
The case study will demonstrate and validate biochar production under real operational conditions, ensuring the end product meets high standards for environmental performance, soil health, and economic value. If proven effective, this solution offers clear benefits to aquaculture producers, local farmers, and the broader environment by closing the loop in nutrient use and reducing waste.
Solution: Solution 5 – A web-based risk assessment system for Harmful Algal Blooms (HABs)
Species: Mussels and Oysters
Country: Scotland
System: Marine
Case Study Lead: SShetl (industry), SAMS (research)
Description: One of the major challenges in shellfish aquaculture is the occurrence of Harmful Algal Blooms (HABs)—events where marine phytoplankton produce biotoxins that can accumulate in shellfish. These toxins pose a risk to human health and often result in temporary farm closures and product recalls, damaging consumer trust and causing significant financial losses for producers.
In Europe, most HABs occur naturally and are highly variable in time and location. Climate change is expected to influence their frequency, intensity, and distribution, creating an even greater need for proactive risk management in the sector.
To address this, Case Study 5 (CS5) is delivering:
Solution 5 – A web-based risk assessment system for Harmful Algal Blooms (HABs): for harmful algal blooms and associated biotoxins. The system builds on existing regulatory monitoring data, which is already collected weekly via light microscopy and chemical testing in most shellfish-producing countries. These datasets—often underutilized—will be aggregated and analysed to provide near real-time updates and short-term forecasts of HAB risk.
By enhancing and integrating current alert systems, CS5 will improve the spatial and temporal interpretation of HAB trends. This enables shellfish farmers to respond more quickly to emerging risks, taking preventative action before blooms cause disruptions.
In addition to supporting the economic resilience of the shellfish sector, this solution will also improve consumer confidence in shellfish safety. The resulting transparency and traceability will encourage dietary shifts toward bivalves—nutritious, sustainable, and climate-friendly sources of protein.
Solution: Solution 6 – A digital tool to monitor the performance and carbon footprint of bivalve production
Species: Mussels
Country: Spain
System: Marine
Case Study Lead: PROINSA (industry), CSIC (research)
Description: Mussel aquaculture is one of the most environmentally sustainable forms of animal protein production, with a remarkably low carbon footprint. However, most greenhouse gas (GHG) assessments overlook emissions linked to mussel metabolism, such as respiration and shell formation (calcification), which can be significant over the culture period.
Farmers are increasingly seeking ways to optimise mussel growth and flesh yield, which depend heavily on environmental conditions like temperature, salinity, pH, food availability, and cultivation technology. Climate change, particularly ocean acidification, is disrupting these conditions—likely reducing growth rates and nutritional quality.
To address this, Case Study 6 (CS6) is developing:
Solution 6 – A digital tool to monitor the performance and carbon footprint of bivalve production: This tool builds on a validated physiological model from the ClimeFish project and incorporates a carbonate system module added during the AquaVitae project. It will now be upgraded with an innovative component that simulates the effects of acidification on mussel metabolism.
The tool will:
Testing and implementation of this solution requires parallel trials with anti-seed predation nets in collector ropes. This solution will enable mussel producers to better anticipate and respond to climate-driven changes, while continuing to deliver low-impact, high-quality seafood.
Solution: Solution 7 – Oyster production deployment time, depth, and seed size optimized for conditions of rising temperature and fouling pressure
Species: Oysters
Country: Sweden
System: Marine
Case Study Lead: Ostrea (industry), IVL (research)
Description: As sea surface temperatures rise and extreme summer warming events become more frequent, oyster farming is increasingly at risk. Higher temperatures can lead to water stratification, increased metabolic stress, and a greater likelihood of disease outbreaks and mortality in cultured oysters. During dry summer periods, reduced precipitation can further limit food availability, compounding the effects of heat stress. Warmer conditions also encourage the growth of fouling organisms that can smother oyster beds and reduce yields.
To manage these risks, adjusting the depth and timing of oyster culture offers a promising solution. Deeper waters may provide cooler, more stable conditions and lower fouling risk—though with the trade-off of slower growth.
To explore this, Case Study 7 (CS7) is developing:
Solution 7- Oyster production deployment time, depth, and seed size optimized for conditions of rising temperature and fouling pressure: An optimised approach to oyster seed deployment, focusing on the effects of culture depth, seed size, and timing under warming conditions. The goal is to evaluate how these variables influence oyster growth and survival during the critical nursery stage.
With warmer waters, it may be possible to deploy oyster seed earlier in the year, extending the growing season. Alternatively, using smaller seed may allow for a shorter, less energy-intensive hatchery phase. By testing different combinations of deployment time, seed size, and depth, CS7 aims to identify the most effective strategies for sustaining oyster production in the face of rising temperatures and fouling pressure.
This solution supports oyster farmers in adapting their operations to a changing climate while maintaining productivity and sustainability.
Solution: Solution 8A – Adapt and develop new seeding material and techniques to reduce carbon footprint
Solution 8B – Demonstrate how kelp deployment in deeper water can reduce fouling and extend growing season
Species: Seaweed
Country: Sweden
System: Marine
Case Study Lead: NSeaF (industry), IVL (research)
Description: Recent life cycle assessments (LCA) of Ulva (sea lettuce) cultivation have highlighted key climate impact hotspots, particularly in the materials used for seeding and the resource-intensive early growth phase. To lower emissions and improve sustainability, there is a clear opportunity to adopt alternative seeding materials and more efficient cultivation techniques.
At the same time, rising sea surface temperatures are expected to shorten the seaweed growing season by accelerating the growth of fouling organisms. As a result, new adaptation strategies are needed to maintain productivity under changing conditions.
To address these challenges, Case Study 8 (CS8) is developing two solutions:
To assess the viability of these strategies, researchers will measure light availability (photosynthetically active radiation) at different depths and evaluate the effectiveness of bivalves in fouling control through co-culture experiments.
Together, these innovations aim to lower emissions and improve the resilience of seaweed farming in a warming ocean.
Solution: Solution 9 – Improved gear design and low emission equipment initiatives
Species: N/A
Country: Norway
System: Marine
Case Study Lead: AKVA (industry), Nofima (research)
Description: Norway’s aquaculture industry generates up to 29,000 tonnes of plastic waste each year, with over 60% currently ending up in landfills or incinerated for energy. Yet, by recycling and reusing plastic from aquaculture gear, it’s possible to reduce global greenhouse gas emissions by up to 50 million kg CO₂-equivalent. Despite compliance with existing regulations on discarded pens and nets, there remains significant untapped potential in closing the loop on equipment use.
Promoting circularity in aquaculture gear is essential for reducing the reliance on virgin plastics and accelerating the transition to more sustainable production—aligned with EU policies such as the Single-Use Plastics Directive and Ecodesign for Sustainable Products Regulation.
To support this transition, Case Study 9 (CS9) is developing:
Solution 9 – Improved gear design and low emission equipment initiatives: Led by AKVA, the world’s largest aquaculture equipment supplier, this solution will leverage extensive datasets on resource use, gear performance, and emissions across the production cycle.
While life cycle assessments (LCAs) in aquaculture have traditionally focused on feed and transport, very few have evaluated the environmental impact of equipment. CS9 aims to close this gap by comparing a conventional sea-based farm using standard equipment with a farm optimised through low-emission gear and circular design principles.
Initial internal LCAs show that recirculated pens can reduce carbon emissions by up to two-thirds compared to traditional pens—highlighting major potential for climate impact reduction. These new pen designs are currently undergoing laboratory validation, with plans to move into sea trials to evaluate performance in real-world conditions. Following validation, full LCAs will be conducted to document their carbon footprint and support market readiness for commercial circular aquaculture products.
Through this work, CS9 will provide actionable recommendations to farmers, suppliers, and industry stakeholders, while contributing to a growing market for low-emission, circular aquaculture solutions.