| Abstract |
The deep ocean is considered the last frontier on Earth, holding resources such as food, minerals and hydrocarbons that increasingly attract human attention as potential alternatives for dwindling stocks on land. However, the deep sea is poorly understood: many areas are yet to be explored, and new species are still found on a regular basis. This lack of understanding hampers our ability to assess the potential impact of human activities in these waters, and limits our capability to design effective management strategies for future activities.
Biodiversity, the main indicator of ecosystem status and functioning, is the key parameter underpinning most ecosystem-based approaches to marine spatial planning and conservation, but measuring it is a major challenge in deep water; traditional sampling schemes are expensive and time-consuming, and their limited coverage makes it difficult to relate the results to regional patterns. Complex deep-sea environments are especially problematic due to their steep and irregular terrain. Ecosystem hotspots such as canyons or coral reefs contain true 3D morphology that cannot be surveyed with conventional techniques. CODEMAP aims to quantify habitat heterogeneity in complex deep-sea terrains, and evaluate its potential as a proxy for benthic biodiversity at a variety of scales. Habitat heterogeneity has been suggested as a major driver for deep-sea biodiversity, but is rarely quantified in a spatial context in the marine realm.
To achieve its goal, CODEMAP will combine the fields of marine geology, ecology, remote sensing and underwater vehicle technology to establish an integrated, statistically robust, and fully 3D methodology to map complex deep-sea habitats. Statistical techniques will be developed to extrapolate quantitative habitat information from fine-scale surveys to broad-scale maps. The optimal parameters to measure habitat heterogeneity will be defined, and their potential as biodiversity indicators tested through correlation with traditional approaches. The project focuses on submarine canyons, but the techniques will also be transferred to other environments. CODEMAP is expected to have a strong impact on the fundamental understanding of the deep sea and on ecosystem-based deep-sea management.
The research is organised around four themes:
- Top-down analysis: robust mapping of habitats and marine landscapes on the regional to medium scale.
- Quantification of habitat heterogeneity and evaluation of its potential as proxy for biodiversity.
- Bottom-up analysis: finding quantitative relationships that can bring information from a more detailed to a broader scale.
- Habitat heterogeneity in 3D through mapping and visualisation.
Fieldwork was carried out on two research cruises. JC060 (RRS James Cook) between May and June 2011. The cruise covered the areas of Rockall Trough, Rockall Bank and Hatton Basin, northwest of Scotland and Ireland, and used an Autosub6000 Autonomous Underwater Vehicle (AUV), newly equipped with an EdgeTech dual frequency high-resolution sidescan sonar plus chirp profiler and a monochrome stills camera, a commercial inspection class ROV, and more traditional equipment including piston-, mega- and boxcores, CTD and shipborne multibeam (EM120 and EM710). The second cruise was from August to September 2015 on board JC125 (RRS James Cook) which covered the Whittard Canyon, south-west of Ireland and the UK. This cruise involved the ROV Isis and AUV Autosub6000, CTDs, ADCPs, piston-, mega- and boxcores, and shipborne multibeam (EM120 and EM710).
Participants
Dr Veerle Huvenne (Principal investigator) National Oceanography Centre, Southampton.
Dr Daniel Jones (Co-Investigator) National Oceanography Centre, Southampton.
Dr Tim Le Bas (Co-Investigator) National Oceanography Centre, Southampton.
Steve McPhail (Co-Inve |
