Seagrass Beds

Seagrass beds develop in intertidal and shallow subtidal areas on sand, mud and fine gravel. They may be found in marine inlets and bays but also in other areas, such as lagoons and channels, which are sheltered fro significant wave action. There are three species of eelgrass Zostera spp. found in the UK, which stabilise the substrate and provide shelter and attachment for other species.

Seagrass

Photo: Gerald Legg

Why are they important?

  • Many fish use eelgrass for shelter and several species of flatfish use them as nursery areas
  • Eelgrass is an important food source for wildfowl such as Wigeon and Brent Goose
  • The beds are an important food source and provide nutrients to support animal communities on the seabed
  • The roots of eelgrass catch and trap sediments, which can reduce coastal erosion

Seagrass Beds in Sussex

Areas of seagrass beds are known off the coast of West Sussex.

What are the threats?

  • Physical disturbance caused by trampling and types of fishing can damage seagrass beds and create turbidity which reduces ability of the plants to photosynthesise
  • Natural factors such as storms and wildfowl grazing can change the extent of seagrass beds
  • Alien species such as Common Cordgrass Spartina anglica and Wireweed Sargassum muticum are able to outcompete native seagrasses
  • A wasting disease caused large areas of seagrass to dieback in the UK during the 1930s

Some associated species

  • Deep-snouted Pipefish Syngnathus typhle
  • Pollack Pollachius pollachius
  • a Stalked Jellyfish Lucernariopsis campanulata
  • Common Cuttlefish Sepia officinalis
  • Common Eelgrass Zostera marina
  • a red seaweed Ceramium rubrum

Short-snouted Seahorse

Photo: Paul Naylor/Sussex Wildlife Trust

Links to more information

The Marine Life Information Network