A hydro-acoustics approach of accessing macrophyte biomass data

Abstract

Hydro-acoustic methods are commonly used to estimate the abundance and distribution pattern of fish in aquatic environments, while studies on the assessment of the biomass of submerged macrophytes in the littoral zones are still rare. In the present study we provide first results showing that indeed this method is a useful tool to estimate the aquatic plant stands in lakes. The aim of the recent presentation is to show an initial data evaluation by graphs describing hydro-acoustic signals at three distinct layers in a small shallow lake: the solid sediment, the fine or muddy sediment, and the ‘plant canopy’ of submerse macrophytes. The most difficulties of data processing and assessment of biomass were for hydro-acoustic records close to the water surface where the echo-signal is interfered by reflectance. Methodological details and progress in evaluating hydro-acoustic records will be discussed.

Keywords

• aquatic macrophytes
• biomass
• hydro-acoustics