Maerl beds
Maerl, or ‘Scottish coral’, is not a coral at all but rather it is an unusual red seaweed which lives unattached on the sea bed either as a thin living veneer above the mud and sand or in great banks and waves. It has a brittle, calcareous skeleton which is easily damaged by mechanical disturbance such as anchors, trawls or dredges. Maerl grows very slowly, typically only 1 or 2 millimetres per year, so its small twiggy nodules may be many years old. Although maerl beds are a relatively rare habitat, they are very important for the survival of many small animals and the juvenile stages of many others including various commercial species which hide and shelter amongst the nodules.