Waste shells are an abundant by-product of aquaculture and seafood-processing, and can be transformed into binders or minerally rich aggregates materials with improved fire resistance.

Bivalves such as mussels and oysters are natural filter feeders that help improve water quality by removing heavy metals and excess nutrients such as phosphorus and nitrogen.  Mussel farming in the EU is carried out in the sea using low-input aquaculture methods that do not require added feed, through four main cultivation modes: rafts, longlines, bottom culture, and bouchot.

Bottom culture requires significantly more time than farming in the water column. Production quantities are large but also volatile; Spain alone reported 192,208 tonnes of mussels in 2022, but outputs can swing sharply in response to spat availability, or when environmental conditions or harmful algal blooms trigger closures in major producing areas. The dominant sectors are the fresh and processed food industry.