European native oysters spawn up to 2 million larvae and help rebuild UK reefs

The European native oyster (Ostrea edulis) is a key UK ecosystem engineer, filtering seawater to improve quality and forming reefs that support biodiversity. They are protandrous hermaphrodites, with a female around 8 cm able to produce about 1 million larvae, up to 2 million in larger individuals per spawning. Populations have declined roughly 95% since the 19th century, but restoration efforts are underway across the coast.