Anja Murray: Native oyster reefs boost marine biodiversity

Pacific oysters from oyster farms are settling into estuarine habitats here, becoming naturalised. in inlets such as Lough Swilly in County Donegal. Picture: Eamonn Farrell/Photocall Ireland
Oyster shells are often seen washed up on beaches: rough on the outside, smooth and shimmering on the inside.
Oysters are familiar, even though they are a mollusc that lives in shallow coastal habitats. Many of us know oysters from restaurant menus — but these are mostly farmed pacific oysters, a species native to China, Japan and Korea, introduced here for cultivation in the 1970s.