Sediment Profile Imagery - Advantages

Advantages

Humans are strongly visually oriented. We like information in the form of pictures and are able to integrate many different kinds of data when they are presented in one or more images. It seems natural to seek a way of directly imaging the sediment-water interface in order to investigate animal-sediment interactions in the marine benthos. Rhoads and Cande (1971) took pictures of the sediment-water interface at high resolution (sub-millimetre) over small spatial scales (centimetres) in order to examine benthic patterns through time or over large spatial scales (kilometres) rapidly. Slicing into seabeds and taking pictures instead of physical cores, they analysed images of the vertical sediment profile in a technique that came to be known as SPI. This technique advanced in subsequent decades through a number of mechanical improvements and digital imaging and analysis technology. SPI is now a well-established approach accepted as standard practice in several parts of the world, though its wider adoption has been hampered partly because of equipment cost, deployment, and interpretation difficulties. It has also suffered some paradigm setbacks. The amount of information that a person can extract from imagery, in general, is not easily and repeatedly reduced to quantifiable and interpretable values (but see Pech et al. 2004; Tkachenko 2005). Sulston and Ferry (2002) wrote about this difficulty in relation to the study of the human genome. Electron microscope images of their model organism (Caenorhabditis elegans) carried a lot of information but were ignored by many scientists because they were not readily quantified, yet that pictorial information ultimately resulted in a deep, and quantifiable, understanding of underlying principles and mechanisms. In the same way, SPI has been used successfully by focusing on the integration of visual data and a few objectively quantifiable parameters in site reconnaissance and monitoring.