Historically, when fishermen in Brittany would land maërl, not only would they land more fish, they would also be able to use the maërl to condition their soils as fertiliser. This meant not only would they get fish, but also a fertile harvest. Hence, this was such a prized commodity; there is a cultural festival of maerl which happens every four years in Brittany- Fête du Maërl. Commercial extraction no longer occurs in Brittany, where it is banned. A friend in Brittany sent me this lovely poster of this year’s fête, which happened in August. Thank you so much Andre!