The Contract Consists Of Two Sections, The Objects Of Which Are: Section 1) The Identification And Counting Of ¬100 Samples Of Benthic Diatoms From Artificial Lakes And The Support Of The Contracting Authority In The Evaluation Of The Limits Of The Existing Ecological Status Classification Index Based On Benthic Diatoms In Artificial Lakes Of The Country. Section 2) The Support Of The Contracting Authority A) In The Investigation And Comparative Analysis Of The Hydromorphological Alteration Assessment Methods Of The Various Member States And Those That Are The Subject Of Discussion In Ecostat, And In The Correlation Of The Criteria They Use In Relation To The National Method, B) In Evaluation Of The Existing And Possibly New Evaluation Criteria For Hydromorphological Alterations Based On Their Correlation With The Biological And Physicochemical Classification Systems Used In The Context Of The Implementation Of Directive 2000/60/Ec In Greece. (EXPIRED)