Survey seabed habitat by remote sensing

This standard covers the knowledge, understanding and skills required to survey the subtidal marine seabed physical habitat as a part of coastal zone management activities. The standard addresses the skills needed to measure, interpret and communicate seabed habitat data to achieve marine conservation objectives and for wider audiences. The skills addressed here assume competence in the fields of Geographical Positioning Systems (GPS) and Geographical Information Systems (GIS).

The survey methods addressed in this standard use the remote sensing principles of interpreting reflected energy (light or sound) from the seabed to enable determination of the basic characteristics of the seabed habitat. These remote methods complement methods that rely on being on the seabed (e.g. diving) or sampling a small area of the seabed and bringing it to a survey vessel for inspection (e.g. grabbing).

You will require a thorough knowledge and understanding of marine seabed habitats and the methods by which they may be remotely sensed. You will also need an understanding of how this information is commonly used in marine environmental management processes, notably through the application of the biotope principle, where habitat, flora and fauna are interrelated, and of national classification systems.

This standard is for those with responsibility for carrying out surveys of the seabed using remote sensing.

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1. plan surveys of a range of marine habitats, at different scales, using remote-sensing methods
2. follow published (national) guidance, policy and procedure documents in line with relevant legislation, statutory requirements, codes of practice and the policies of your organisation
3. carry out risk assessments before beginning survey activities
4. carry out your work in accordance with the relevant environmental and health and safety legislation, risk assessment requirements, codes of practice and policies of your organisation
5. prepare and deploy equipment for surveys relevant to the mapping of specific marine habitats, at required scales
6. undertake field checks to confirm optimum data quality under varying water column conditions
7. apply quality assurance and control procedures to data collection and storage
8. apply spatial-data-processing methods to reveal habitats
9. link data to a) ground-truth information and b) recognised biotope substrate descriptors
10. identify marine habitats and explain their geospatial context
11. communicate the data to clients and wider audiences
12. contribute to discussions on data interpretation limitations and significance

1. the classification of marine habitats
2. the relevant legislation, statutory requirements, codes of practice and the policies of your organisation for carrying out surveys of seabed habitat by remote sensing
3. the importance of carrying out risk assessments before beginning survey activities
4. your responsibilities under the relevant environmental and health and safety legislation, risk assessment requirements, codes of practice and the policies of your organisation
5. how to deploy and use data logging procedures for the most commonly used remote-mapping systems
6. the factors that can affect the quality of field data
7. data safety, quality control procedures for acoustic and optical data sets, data back-up and archiving
8. how to process spatial data using GIS or CAD-based technology
9. the seabed sample description systems
10. marine seabed classification principles and systems
11. the methods of graphic and written communication for geospatial data
12. the limitations and advantages of specific remote-mapping methodologies

Communication of result*s* includes: images, xyz data, layering, written descriptors

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Data-processing methods include: smooth/simplify/mosaic/enhance/contour data, GIS and CAD systems, proprietary software

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Equipment: echo sounding, multibeam, side-scan sonar, AGDS, sub-bottom profiling, LIDAR, satellite imagery, aerial photographs, towed camera and video

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Marine: the area from the inter-tidal zone (highest water mark) out to the limit of the territorial waters (12 nautical miles)

Marine seabed habitats: depth, energy levels, rock and hard ground, sediments, macroflora, biogenic morphology.

• the key elements that can be mapped are depth, rock outcrop, sediment deposits, macro algal beds and (more rarely) faunally generated features

Scales: micro, local, broad (landscape)

Water column conditions affecting *data quality:* equipment mounting/deployment attitude, vessel speed, density stratification, strong currents, waves, obstructions