
A recent in-depth Life Cycle Assessment (LCA) study of mariculture in Greece has emphasised the value of such analyses in crafting a roadmap for collaboration among industry stakeholders, policymakers, and researchers, paving the way for a more sustainable future for aquaculture.
Greece, a leading producer within the European Union, achieved a production of 131,250 tonnes of fish in 2021, valued at €844 million, representing 17.4% of the EU’s total output. This production plays a significant role in meeting seafood demand across the Mediterranean.
Led by Evangelos Kallitsis and Pavlos Avramidis, Imperial College London and the University of Patras, respectively, the analysis focused on four key species—gilthead seabream, European seabass, meagre, and red seabream—which collectively reached an estimated value of €652.45 million in 2021, according to the Hellenic Aquaculture Producers Organisation. In contrast, the value of freshwater aquaculture species in Greece for the same year was significantly lower, totalling €10.7 million.
This study distinguishes itself from previous efforts by adopting a "cradle-to-gate" approach, encompassing every stage of production, from feed formulation and fry production to packaging. The methodology adheres to the ISO 14040/44 standards, ensuring a robust and standardised framework.
The results confirm that fish feed production is the largest contributor to aquaculture’s environmental impact, accounting for up to 79% of greenhouse gas emissions in certain species. Data on feed production were gathered from a single facility, which provided detailed information on the composition and energy requirements for feed manufacturing.
Fry production also emerged as a critical stage, with data collected from three hatcheries producing a combined total of 52 million juveniles annually, each with an average weight of 2.1 grams. This phase is particularly impactful for species with higher fry input requirements.
In the fish-rearing stage, data were obtained from four companies producing a combined total of 24,509 tonnes in 2021. These companies operate 16 sea-cage farms in western Greece and five in the central region, with most cages located less than 500 metres from the coastline.
The study also examined the fish processing and packaging stage, drawing data from three facilities with a combined processing capacity of approximately 34,000 tonnes annually. This analysis enabled the quantification of material consumption, energy use, and environmental emissions per tonne of packaged fish.
Among the species analysed, red seabream exhibited the highest global warming potential (GWP), producing 4,161 kg CO2-eq per tonne, while gilthead seabream had the lowest GWP at 2,270 kg CO2-eq per tonne. These differences stem primarily from variations in feed conversion ratios (FCR) and fry input requirements. Other significant environmental concerns include eutrophication, driven by nitrogen and phosphorus emissions during fish rearing, and the energy-intensive nature of hatchery operations.
Improving the sustainability of Greek aquaculture requires coordinated efforts at every stage of production. Reformulating fish feed to include alternative ingredients, such as plant-based proteins, insect meal, or agricultural by-products, could significantly reduce the sector's reliance on fishmeal and fish oil.
Additionally, improving feed digestibility and minimising waste would help to lower greenhouse gas emissions.
Within the fish-rearing process, adopting better management practices to reduce feed consumption and improve FCR is essential. This could include genetic improvement programmes to breed fish that are more resistant to diseases and more efficient in growth.
Enhancing the quality of juveniles is also critical, as the fry and pre-grow stages are among the most impactful phases. Reducing losses during these stages could significantly decrease environmental impacts.
Furthermore, fostering innovation is paramount. Solutions such as adopting renewable energy sources, including solar and wind power, in aquaculture operations could reduce the industry's dependence on fossil fuels and lower its carbon footprint.
The study highlights the pressing challenges facing Greek aquaculture but also underscores the critical need for ongoing research and innovation to secure its sustainable growth. This comprehensive life cycle assessment offers a roadmap for collaboration among industry stakeholders, policymakers, and researchers, paving the way for a more sustainable future in aquaculture.
This analysis sets a new benchmark for the Mediterranean region, where Greece’s leadership could inspire neighbouring countries to adopt more sustainable practices, ensuring the balance between production and environmental responsibility.