Abstract
Spatial mapping of the marine environment is challenging when the properties concerned are difficult to measure except by shore-based analysis of discrete samples of material, usually from sparsely distributed sites. This is the case for many seabed sediment properties. We developed an indirect approach to mapping the organic content of coastal sediments from hydro-acoustic reflectance data. The basis was that both organic matter and acoustic reflectance are related to sediment type and grain size composition. Hence there is a collateral relationship between organic matter content and reflectance properties which can be exploited to enable high resolution mapping. We surveyed an area of seabed off the east coast of Scotland using a vessel mounted single beam echosounder with RoxAnn signal processing. Organic carbon, nitrogen and phytoplankton pigment contents were then measured in material from grab and core samples collected at intervals over a year. Relationships between the organic components and hydroacoustic characteristics were derived by general additive models, and used to construct high resolution maps from the acoustic survey data. Our method is an advance on traditional interpolation techniques sparse spatial data, and represents a generic approach that could be applied to other properties.
Original language | English |
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Pages (from-to) | 265-284 |
Number of pages | 20 |
Journal | Hydrobiologia |
Volume | 680 |
Issue number | 1 |
Early online date | 29 Nov 2011 |
DOIs | |
Publication status | Published - Jan 2012 |
Bibliographical note
AcknowledgementsThis work was co-funded by the Marine Scotland—Science Laboratory Aberdeen, and University of Aberdeen, through the joint Fisheries Research Fund. In
addition, the authors acknowledge the support of the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) in the completion of this study. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. Our thanks to the captains and crews of the research vessels Scotia, Clupea, Alba na Mara and Temora, and to our colleagues who have assisted with various aspects of the work at sea and in the
laboratory, especially John Dunn, Steve Hay, Eric Armstrong, Phil Copland, Pete Hayes, Jane Heron, Colin Megginson, Charlie Shand and Paul Stainer. Thanks also to Doug Webster for help with the graphics and for his constant support.
Keywords
- Single beam RoxAnn
- Ground truthing survey
- Hardness
- Roughness
- Total organic carbon (TOC)
- Total nitrogen (TN)
- Chlorophyll-a
- Pheophytin-a
- Scotland
- UK
- COASTAL MARINE-SEDIMENTS
- ISLAND SOUND SEDIMENTS
- NORTH-SEA SEDIMENTS
- CHLOROPHYLL-A
- CLASTIC SEDIMENTS
- SOUTHERN BIGHT
- CARBON FLUX
- PRESERVATION
- COMMUNITIES
- ASSEMBLAGES