The Ythan Nitrate Vulnerable Zone has been designated on the basis of criteria set out at Annex IA(3) of the EC Nitrates Directive (91/676/EEC), i.e. that the estuary is eutrophic, or in the near future may become eutrophic.During its 1997 review of eutrophic waters, the Scottish Environment Protection Agency (SEPA) concluded that the Ythan estuary met thre...