Still Waters

Standing freshwater habitats – from the smallest farm pond to gravel pit lakes of many hectares – are among the most species-rich features in the Suffolk landscape, and among the most rapidly lost. The UK is estimated to have lost around 70% of its ponds since 1900, with those that remain often degraded by nutrient enrichment, shading and the spread of invasive non-native species. In Suffolk, however, significant opportunities exist alongside the losses: the extraction of sand and gravel along river valleys has created a legacy of large water bodies that, with appropriate management, can develop into high-quality freshwater habitat.

The character of still water habitats varies enormously with depth, water chemistry, substrate and catchment land use. The pingos – periglacial melt-water ponds – of the Breckland are a nationally rare feature of great ecological significance, their isolation and antiquity having allowed the development of specialist aquatic communities including several plant and invertebrate species of restricted range. Farm ponds, when kept clean, support great crested newt, water vole, dragonflies, and a diversity of aquatic invertebrates that reflect the productivity of standing water in calcium-rich agricultural landscapes. Gravel pit complexes in the river valleys of the Lark and Stour have developed into important sites for wintering wildfowl, breeding tern species and aquatic invertebrates.

The great crested newt (Triturus cristatus) is the assemblage flagship, its population in Suffolk representing one of the more significant concentrations in England. It requires ponds with relatively clear, neutral-to-slightly alkaline water, fish-free or low-fish conditions, and sufficient nearby terrestrial habitat for foraging and hibernation. Its sensitivity to water quality and pond condition makes it a reliable indicator of broader still water habitat health. Suffolk’s great crested newt populations are largely dependent on the pond network within the farmed landscape – a network whose continuity and quality are under pressure from agricultural drainage, infilling and neglect.