In Italy mussel shells are famous to purify the water. It's important to remember though that mussels growing on very dirty waters (like sewers outgoing in the

In Italy mussel shells are famous to purify the water. It's important to remember though that mussels growing on very dirty waters (like sewers outgoing in the sea) might be contaminated and are not edible. https://e360.yale.edu/features/how_mussel_farming_could_help_to_clean_fouled_waters https://e360.yale.edu/features/how_mussel_farming_could_help...