ESTIMATION OF MACROPHYTES USING SINGLE AND MULTIBEAM ECHO SOUNDERS AND SIDESCAN SONAR IN ARCTIC FJORDS (HORNSUND AND KONGSFJORD, WEST SVALBARD)

• Main Authors: A. Krussa, J. Tegowskib, Ph. Blondelc
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Seafloor classification; Arctic environment; habitat mapping; algae; image; Arctic; Hornsund; Kongsfjord; Svalbard; Climate change; Kongsfjord*; Kongsfjorden
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.487.8548; http://promitheas.iacm.forth.gr/uam_proceedings/uam2009/30-6.pdf

Abstract: The characterisation of sea vegetation over large areas and at all depths needs very efficient and cost-effective tools such as acoustic methods. We present here an acoustic method for the evaluation of benthic habitats in Arctic periglacial environment. The great intensity and rapid changes of morphodynamic processes in the biotic environment of Arctic fjords make them prime areas to research climate change impacts on ecosystems. This paper presents comparative results of study on the spatial distribution and biomass of macrophytobentos in two Svalbard fjords, Hornsund and Kongsfjord. Acoustical data in Hornsund fjord was collected by systematic surveys with co-registered single-beam echosounder and side-scan sonar data. For classification of acoustical imageries of bottom covered by algae, we developed algorithms using multidimensional wavelet decomposition of echo signals and fuzzy-logic clustering. Classification results are supported by video recordings and biological samplings by divers. Another, slightly different data collection approach was used in Kongsfjorden, with simultaneous single-beam and multibeam echosounder recordings, verified by biological samplings and observations. Both methods provide maps of phytobenthos distribution and biomass estimation in the fjords investigated. Comparison of single-beam and multibeam echosounder results proved a great opportunity for understanding the visualisation of macrophytes by multibeam systems and potential improvements to associated macrophytobentos recognition techniques.