Eutrophic Standing Waters

Eutrophic standing waters are highly productive because plant nutrients are plentiful, either naturally or as a result of artificial enrichment. These waters are characterised by having dense, long-term populations of algae in mid-summer and their beds are coverd by dark anaerobic mud, rich in organic matter.

Woods Mill lake

Photo: Elli Saunders/Sussex Wildlife Trust

Why are they important?

  • Reservoirs and lakes can support important populations of breeding and wintering wildfowl.
  • Eutrophic waters support numerous species of invertebrates and can be particularly important for dragonflies.
  • Some of our more threatened aquatic species such as the White-clawed Crayfish can be found in eutrophic waters.

Eutrophic standing waters in Sussex

A number of eutrophic standing waters such as lakes, reservoirs, canals and hammer ponds are found across Sussex.

What are the threats?

  • Pollution from run-off causes nutrient enrichment and results in reduced water quality.
  • Changes in water levels due to over-abstraction, which can also intensify eutrophication.
  • Introduction of invasive non-native species, which affect native wildlife
  • Disturbance and habitat degradation caused by recreation and changes in land-use.
  • Heavy stocking with fish can cause turbidity, which affects the aquatic communities in the water body.

Some associated species

  • European Eel Anguilla anguilla
  • European Otter Lutra lutra
  • Lesser water measurer Hydrometra gracilenta
  • Desmoulin’s whorl snail Vertigo moulinsiana
  • True Fox-sedge Carex vulpina
  • Fennel Pondweed Potamogeton pectinatus

White-clawed Crayfish

Photo: Andy Kirkland

Advice on eutrophic standing waters

After Minerals
Pond Conservation
Sussex Wetland Landscapes Project