Seasonal variations of water quality and aquatic macrophytes survey based on side scan sonar, in a shallow coastal lagoon (Gialova, SW Peloponnesus, Greece)

Gialova lagoon is located in the north-west of Pylos city (Prefecture of Messinia, SW Peloponnesus) and is part of the Ecological Network “Natura 2000”. The aim of the current research is the assessment of the ecological quality of the lagoon using hydroacoustic technique and the monitoring of abiotic and biotic parameters on seasonal basis. Side scan sonar imagery resulted in 6 different lagoon floor acoustic types which correspond to different percentage of vegetation cover. Samplings of aquatic vegetation were carried out from 9 different sampling stations oriented by the results of the hydroacoustic survey. Macrophytes Ruppia cirrhosa and Cymodocea nodosa but also chlorophyte Cladophora glomerata were recorded in the lagoon floor. Key water quality parameters and primary production (Chlorophyll-a) were monitored seasonally at nine stations. Chl-a and TP seems to be the main responsible parameters for the eutrophic ecological status of the lagoon.