Seabed habitat mapping techniques: an overview of the performance of various systems

Abstract

Seabed mapping has become vital for effective management of marine resources. An important role in moving towards ecosystem based management is played by the defining and understanding of the relationships among marine habitat characteristics, species distribution and human activities. Mapping seabed characteristics by means of remote acoustic sensing, using seabed seismic profiling, sidescan sonar, or echo-sounder based classification systems, is becoming of increasing importance. This paper gives a brief overview of existing marine habitat mapping technologies and their recent developments. In singlebeam echo-sounders, using multiple frequencies will be useful in classifying the seabed. It must be observed that the resolution of a sidescan sonar with narrower along-track beam width and higher range sampling rates will be better than a multi-beam echo-sounder, although the specifications of the newer systems are much improved. Airborne LIDAR bathymetry is very useful for shallow water seabed mapping, particularly in challenging rocky areas vulnerable for ship-based mapping operations. Seabed maps are essential in any case for siting of bottom mounted energy devices. The utmost care should be taken at all stages of the classification process, such as input data, control of interfering factors, seabed acoustic attributes, classification methods and ground-truth observations.

Monitoring deep Mediterranean rhodolith beds

“…The comparison of different survey techniques showed that the areal extension of RBs is conveniently defined by the use of acoustic methods . Acoustic mapping technology (side scan sonar and multibeam echosounder) is used for morpho-sedimentary or biological habitat discrimination, or both approaches (Smith and Greenhawk, 1998;McRea et al, 1999;Ojeda et al, 2004;Panadian et al, 2009), and must be effectively calibrated by ground-truthing (grab sample, box-corer, submarine video, ROV, diving) (Ehrhold et al, 2006;Brown et al, 2011;Barberá et al, 2012;Savini et al, 2012).…”

The Challenge of Managing Marine Biodiversity: A Practical Toolkit for a Cartographic, Territorial Approach

“…In this regard, the landscape approach has several advantages for the practical application of EBM. Landscape components are the natural elements to be represented on maps, and the basic information on their spatial distribution may be easily obtained thanks to the growing availability of data collected by remote techniques [44]. Some examples of cartographical representations, at a reduced scale, are provided in the present paper to show their general aspect.…”

Single-beam acoustic variability associated with seabed habitats

“…T Anderson et al, 2008;Pandian et al, 2009), little attention has been given to the inherent acoustic variability and the optimal spatial step to integrate single-beam acoustic data. This study focused on these aspects, using as test data an acoustic survey conducted on the Portuguese continental shelf, covering an area of approximately 5400 km 2 , between 15 and 150 m water depth and with sediments varying from mud to fine gravel.…”