Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species the valves are highly calcified, and many are somewhat irregular in shape. These calcified structures are especially vulnerable to increased Ocean acidification.
European oyster, that will be studied in Spanish case, is cultured in rafts, with a production of about 28 tonnes. Pacific oysters (Crassostrea gigas) will be investigated in Scotland, as the main shellfish species produced in terms of value and tonnage; 271 tonnes assuming average individual weight of 80g.