New Technologies for Benthic Habitat Mapping

Authors:

  • Hans Kautsky
  • Michael Tulldahl
  • Ove Steinvall
  • Niklas Strömbäck
  • Sofia Wikström

Publish date: 2010-09-20

Report number: FOI-R--3013--SE

Pages: 56

Written in: English

Keywords:

  • Benthic habitat mapping
  • vegetation
  • classification
  • laser
  • lidar
  • fluorescence
  • multispectral
  • hyperspectral

Abstract

There is a demand from the authorities to have good maps of the coastal environment for their exploitation and preservation of the coastal areas. The subject of this report is a literature study of the state-of-the-art and possible future methods for producing maps of the biota under water that are based on actual observations. We aim to find methods for generation of actual maps of the biota the same way as is done with aerial photography, the evident base for most land based maps. The focus of the report is benthic (sea bed) habitat mapping with laser and other optical techniques from aerial platforms. Other mapping techniques (sonar), methods (field observations, spatial modelling) and survey platforms (satellites, underwater and surface platforms) are briefly discussed. The report includes a brief summary of the methods used up to today to map shallow plant and animal communities. We conclude that several new technologies are of interest for benthic habitat mapping. For existing and new sensors, we foresee that the methodology will be developed by better and more automated algorithms for data exploration and for fusing different data sets together. For the first few metres below the sea surface, airborne and spaceborne, passive multi- or hyperspectral imaging systems are of great interest for mapping. Airborne laser techniques for collection of depth can be considered as operational. With sensor and algorithm development the airborne depth sounding laser is a highly interesting method for mapping of shallow underwater habitats. Future laser systems with higher efficiency together with high-sensitivity receivers may enable laser systems which include multiple-wavelength channels , fluorescence, and other spectral techniques to increase classification and mapping performance. Development of platforms with autonomous operation can reduce cost of operation and limit manpower involvement. Small aerial platforms may already today be useful for low-cost benthic habitat mapping in the most shallow areas. This report is a part (Aquatic Work Package 3, WPA3) of the work within the EMMA project (Environmental Mapping and Monitoring with laser And digital images) financed by the Swedish Environmental Protection Agency, SEPA. The focus in the EMMA project is on using remote sensing data from operational systems on airborne platforms, but in WPA3 we also consider future technologies of interest in a long-term view. The ultimate goal is to obtain quick, accurate and automatic methods that cover large areas and show the actual state of the shallow-water ecosystems along the Swedish coast.