AQUA 2024

August 26 - 30, 2024

Copenhagen, Denmark

LIFE-CYCLE ASSESSMENT OF NEARSHORE VERSUS RECIRCULATING AQUACULTURE SYSTEM (RAS) FOR SEA BREAM FARMS

Natalie R. Rizzo*, Olivier Jolliet

 

Denmark Technical University, DTU Sustain, Quantitative Sustainability Assessment

Bygning 115, Bygningstorvet

2800 Kongens Lyngby

 

natri@dtu.dk

 



Aquaculture is  presently  growing  to anticipate the significant  need for human population growth , healthy foods, and the predicted rise in seafood consumption. Over 90 % of market-available sea bream originates from  aquaculture farms in  the Mediterranean, which might generate substantial environmental impacts .  Therefore, it is necessary to compare nearshore farms with recirculating aquaculture systems (RAS) to evaluate environmental footprint, nutrient recycling, and disease control.

 This study performs a comparative LCA on a modeled  nearshore  and RAS farm producing 100 metric tons of sea bream yearly. Using  two modeled farms in Greece , the differences in environmental impacts and factors that can contribute to sustainability improvements throughout the sector are highlighted .

 The primary contributors to the carbon footprint of the RAS and nearshore sea bream farms are the production of the feeds and the generation of electricity required for the RAS system. T he  carbon footprint of RAS farms varies with the electricity grid mix, showing  higher impacts  with  the Greek electricity grid than with the Turkish grid ,  which vastly exceeds the  footprint  of  nearshore farming (see figure) . However, powering RAS entirely with  photovoltaic produces the lowest  carbon footprint across all evaluated scenarios. Comparisons between organic matter, nitrogen, and phosphorus emissions to waterways also show  a substantial reduction in discharge amounts from the RAS, lending it to  being a superior choice regarding eutrophication impacts in the coastal zones .

 The RAS system has a higher carbon footprint with  the  present electricity mix than nearshore production. RAS only becomes a fully sustainable solution if the electricity comes from renewable energy sources while reducing nutrients released to the environment.   These data also  provide consumers with greater transparency regarding the environmental impacts of their food, further advancing the movement toward greener farming solutions.