Publication abstract
The combination of Sediment Profile Imagery (SPI) and DGT technology for sediment health assessments
Parker R., Kröger S., Teal L., Mason C., Bolam T., Birchenough S.,Fones, G..,. Solan M.
At present, significant effort is being made to develop indicators of ecosystem health, which can be used as tools to support various European legislative and policy frameworks in relation to the management of human activities. The recent European Marine Strategy Framework directive (EMSFD) has ‘seabed integrity’ as a key descriptor of Good Environmental Status (GES). A challenge for regulators is to develop indicators which can be used to track seabed status and functional change (physical, chemical and biological) as a result of natural or human derived pressures.
Sediment Profile Imagery (SPI) isan in-situ technique, which takes vertical profile pictures of the upper 20cm of the sediment system. Images can provide clear insight into the relationship between benthic communities and sediment properties. Rapid temporal and spatial assessment of soft sediment state and function can be made by using sediment colour as a proxy for redox state (Fe3+/Fe2+ boundary). SPI images are also an excellent means of communicating sediment oxygenation and ecological data in a simple format to non-specialists.
For SPI assessments to be successful, chemical detection alongside imaging is highly desirable in order to calibrate and support image interpretation for sediment function.
Results from two studies which aim to combine SPI with information on sediment chemical composition via DGT gel probes (g-SPI) are discussed. Studies presented will include the application of the gel techniques to detection of pore-water chemistry associated with contaminated dredge material (CDM) and capping trials from Tyne disposal sites and from background stations off the North Dogger. Both studies have demonstrated the advantages gained by combining the techniques and their joint utility for assessment and monitoring of seabed health.
