County Wildife Site Criteria for Cornwall Appendices

EUTROPHIC STANDING WATER PHTGeneral DescriptionEutrophic standing waters are highly productive because plant nutrients are plentiful, either naturallyor as a result of artificial enrichment.In their natural state eutrophic waters have high biodiversity. Planktonic algae and zooplankton areabundant in the water column, submerged vegetation is diverse and numerous species of invertebrateand fish are present. Plant assemblages differ according to geographical area but common floatingleavedplants include yellow water lily Nuphar lutea and there is often a marginal fringe of reedswamp,which is an important component of the aquatic ecosystems.National ContextEutrophic waters are most typical of hard water areas of the lowlands of southern and eastern Britain,but they also occur in the north and west, especially near the coast.There are no accurate estimates of the amount of eutrophic standing water in Great Britain. The totalarea of still inland water is estimated as 67 500 ha in England, 12 500 ha in Wales and 160 000 ha inScotland. Current work suggests that over 80% of this resource in England, some 40% in Wales andapproximately 15% in Scotland is eutrophic. On this assumption, the area of eutrophic standing waterin Britain would be about 84 500 ha (178 500 ha UK).Area of PHT in Cornwall (ha): 2800.3% National TotalFor this habitat the threshold is 0.3 haWe have not mapped the distribution of this PHT.Appendix 4 - Information Relating to Priority Habitat TypesCounty Wildlife Sites Criteria