Submarine canyons are the main conduits between the shelf and the deep sea, funneling sediments, nutrients and carbon, but also pollutants between shallow and deep water. They are considered biodiversity hotspots, because their complex morphology creates a large number of ecological niches that attract a diverse fauna (Amaro et al., 2015; Fernandez-Arcaya et al., 2017). In addition, the irregular terrain results in specific oceanographic and sediment transport processes, such as internal waves with amplitudes >100m, or regular sediment flows. For benthic ecosystems, this causes a level of natural disturbance that is substantially higher than the average in deep-sea environments.
In recent decades, disturbance caused by human activities has increased, particularly due to bottom trawling, This fishing practice can result in additional sediment flows, mechanical abrasion of the seabed, and displacement of organic carbon stocks. To manage this situation, marine protected areas can be designated that limit or prohibit bottom-contact fisheries. To understand the true impact on the benthic ecosystem of both the bottom trawling and the management measures, it is first of all necessary to quantify the natural variability of canyon habitats in space and time.
This PhD investigates how the mosaic habitats and their associated fauna in submarine canyons cope with natural disturbance processes, and how this can be applied in a conservation context. The research will aim to answer the questions: what is the natural rate of change of benthic communities in submarine canyons? Do the natural and/or anthropogenic disturbance events cause changes in habitat distribution, extent, patchiness, or changes in community composition or the health status of key ecosystem engineers? Do these patterns differ between canyons close to land, and those further offshore?
This PhD will focus on both a land-detached, and a land-attached canyon, and will be based on existing and recently collected data from the Whittard Canyon system, Celtic Margin (which includes “The Canyons” UK Marine Conservation Zone), plus new data to be collected on the Eurofleets ‘ERODOTO’ expedition in Squillace Canyon offshore Italy. The datasets combine ROV video and photogrammetry data with high-resolution AUV bathymetry, including repeat observations at several locations in Whittard Canyon.
[1] Compare how community composition has changed over time. Quantitative analysis of video/photography data from several locations in the Whittard Canyon system, surveyed in 2015 and 2022, carried out in the online BIIGLE video annotation software, will be interpreted against knowledge about sediment transport and internal wave patterns recently gathered through collaborations in the CLASS project.
[2] Quantify changes in small-scale species distribution patterns, habitat distribution and extent.
Habitat maps will be created from the repeat high-resolution mapping and photogrammetry data, to quantify changes in habitat distribution and extent (Zelada Leon et al, 2020). Novel point pattern analysis from photogrammetry mosaics will quantify changes in small-scale species distributions, and focused comparisons of individual specimens/colonies will inform about changes in the health status of key ecosystem engineers.
[3] Compare functional community composition, abundance and diversity between a land-attached and land-detached canyon. BIIGLE image analysis results of both Whittard and Squillace Canyon data will be analysed with multivariate statistical techniques to identify functional differences in faunal communities.
The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at the National Oceanography Centre Southampton within the Ocean BioGeosciences group. The PhD will be linked to the NERC CLASS programme, (https://projects.noc.ac.uk/class-project/) and will provide plenty of opportunities for networking with the wider submarine canyons research community (INCISE, www.incisenet.org), and international colleagues studying Whittard and Squillace canyons. The concept of the PhD is inherently multidisciplinary, and the candidate will have the opportunity to join offshore research campaigns or to spend a period of time at a collaborating research institute. Specific training relevant to a future academic career and across a range of offshore industries include: i) Quantitative marine image analysis and species ID ii) GIS, iii) Habitat mapping, including using marine autonomous and robotic systems; iv) Numerical ecology and multivariate statistics; v) geological, sedimentological and oceanographic processes of the continental margin.
Please see https://inspire-dtp.ac.uk/how-apply for details.
- Amaro, T., Huvenne, V.A.I., Allcock, A.L., Aslam, T., Davies, J.S., Danovaro, R., De Stigter, H.C., Duineveld, G.C.A., Gambi, C., Gooday, A.J., Gunton, L.M., Hall, R., Howell, K.L., Ingels, J., Kiriakoulakis, K., Kershaw, C.E., Lavaleye, M.S.S., Robert, K., Stewart, H., Van Rooij, D., White, M., Wilson, A.M., (2016). The Whittard Canyon - a case study of submarine canyon processes. Progress in Oceanography, 146, 38-57. Doi:10.1016/j.pocean.2016.06.003
- Fernandez-Arcaya, U., Ramirez-Llodra, E., Aguzzi, J., Allcock, A.L., Davies, J.S., Dissanayake, A., Harris, P., Howell, K., Huvenne, V.A., Ismail, K., Macmillan-Lawler, M., Martin, J., Menot, L., Nizinski, M., Puig, P., Rowden, A., Sanchez, F., Van den Beld, I., (2017). Ecological role of submarine canyons and need for canyon conservation: a review. Frontiers in Marine Science, 4,5 doi:10.3389/fmars.2017.00005
- Zelada Leon, A., Huvenne, V.A.I., Benoist, N.M.A., Ferguson, M., Bett, B.J., Wynn, R.B. (2020). Assessing the repeatability of automated seafloor classification algorithms, with application in Marine Protected Area monitoring. Remote Sensing, 12, 1572. Doi:10.3390/rs12101572
