Saline Lagoons
Lagoons are natural or artificial bodies of saline water partially separated from the sea by shingle, sand, a rocky shore or sea wall. Seawater input can be through percolation, via a channel or by overtopping.
Photo: Peter Wakely/Natural England
Why are they important?
- The salinity of lagoons can vary considerably, and they support specialised species of plants and animals, which reflect the degree of salinity.
- Lagoons often have soft sediments (mud or sand) making them important for burrowing invertebrates, and stoneworts some of which are extremely rare.
- Lagoons provide important habitat for birds.
Saline Lagoons in Sussex
In Sussex saline lagoons cover about 190 hectares over around 30 sites, which is around 3% of the total UK resource.
What are the threats?
- Saline lagoons will often naturally fill-in through vegetation succession. This would naturally be offset by lagoon creation; however this may be limited by human activity.
- Pollution, particularly through nutrient enrichment, affects the vegetation community.
- Artificial control of water input to lagoons will affect salinity.
- Coastal defence work can interrupt natural sediment movement which affects coastal habitats and structures including lagoons.
- Sea level rise will lead to the loss of some lagoons; however it may also result in the creation of new ones.
Some associated species
- Three-spined Stickleback Gasterosteus aculeatus
- Knot Calidris canutus
- Sea Slater Ligia oceanica
- Lagoon Cockle Cerastoderma glaucum
- Tasselweed Ruppia spp.
- Foxtail Stonewort Lamprothamnium papulosum
Photo: Ian Rose
Where to visit
Rye Harbour Nature Reserve
Widewater Lagoon
Sussex Targets
Biodiversity Action Reporting System Website
