Sea Lettuce

Ulva lactuca


Sea Lettuce is a common seaweed of many different beach habitats; it can often be found attached to rocks in sheltered shores, but also thrives in rock pools even if it has become detached from its substrate. Its holdfast portions (the area that sticks to the substrate) are perennial and grow new fronds each spring.

How to identify

Sea Lettuce lives up to its name: it looks like green, floppy lettuce leaves which are often tatty in appearance but are quite tough.

Where to find it

All around our coasts.


When to find it

  • January
  • February
  • March
  • April
  • May
  • June
  • July
  • August
  • September
  • October
  • November
  • December

How can people help

Seaweeds provide a vital link in the food chain for many of our rarer species. Our seas and coastline are in need of protection if we are to keep our marine wildlife healthy. The Wildlife Trusts are working with fishermen, researchers, politicians and local people towards a vision of 'Living Seas', where marine wildlife thrives. This work has recently had a massive boost with the passing of the Marine Bill, promising sustainable development of the UK's marine environment. Do your bit for our Living Seas by supporting your local Wildlife Trust.

Species information

Common name
Sea Lettuce
Latin name
Ulva lactuca
Seaweeds and grasses
Length: up to 100cm Frond width: up to 30cm
Conservation status