Disturbance and recovery of benthic habitats in submarine canyon settings

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? 

For full project details visit the Inspire project page.