Species Focus - Carrageen (Chondrus crispus)

Take a trip to the lower shore, or before you get there, look in some rockpools on the midshore, and you will most likely come across some Carrageen, otherwise known as Irish moss (Chondrus crispus). As a perennial, Carrageen can be found all year round and across the whole of the NE Atlantic on the shores and shallow subtidal zone.

Carrageen is a red seaweed (macroalga), between 5 and 25 cm, typically a maroon colour, but after exposure to excessive sunlight, can be bleached to green or even white. This illustrates the presence of the green pigment chlorophyll as well as the red pigment phycoerythrin.

Carrageen has a branching pattern common to algae, called dichotomy, where each frond forks to 2 equal parts, up to 5 times, resulting in a fan-shaped outline to the plant. Each fork tends to narrow towards the tips. The plant is attached to stable rocks by a discoid holdfast, from which numerous fronds may grow. The frond is relatively cartilagenous, meaning that it will hold its own weight out of water, rather than collapsing

Carrageen is one of the more edible seaweeds, mainly used as a thickener in soups, stews or to make vegetarian junket (blancmange). Give it a go, but just make sure you wash the sand off first! Records show a decline in recent years, probably due to changing recording behaviour, rather than reduction in presence, but to confirm this, please submit your records, ideally with photos, to the Cofnod ORS or the LERC Wales App.