Phd students

PhD students within the research area Coastal Ecology.

Aris ThomasbergerAris Thomasberger

Title of PhD project

Development of tools for cost-effective monitoring of subaquatic vegetation

Supervisors

Mette Møller Nielsen, Jens Kjerulf Petersen and Mogens Flindt

Background of project

Eelgrass is a key element and indicator species for water quality in the European Union Water Framework Directive. To ensure that the Danish shellfish fishery complies with EU environmental directives, eelgrass is fully protected within Natura 2000 areas under the Danish Mussel Policy and environmental impact assessments have to be carried out before fishing activity can commence. Consequently, detailed knowledge on eelgrass distribution is of high importance.

About the project

The project will carry out extensive studies with drones in water bodies of different characteristics to explore the possibility of implementing drone technology in future mapping of subaquatic vegetation. I will focus on the development of new methods for eelgrass mapping in environmentally complicated areas with deep and/or turbid waters. Different sensor/platform combinations and new approaches to image classification processes will be tested to explore strengths and limitations of drone based mapping. The project is funded by the EMFF and will be carried out in close collaboration with other sections of DTU Aqua, the DTU Space Drone Center and SDU's drone group at the Department of Biology.

Perspective

The project is expected to develop new technological methods and tools that in the future can ensure an economically and professionally sound mapping of subaquatic vegetation in Danish coastal waters. Of special interest will be Natura 2000 areas where fishing with bottom trawling takes place, thus is subject to the Danish Mussel Policy. The developed methods are expected to be directly applicable in the annual impact assessments for mussel and oyster fisheries as a more accurate and cost-effective alternative to the current point specific video surveys. In addition to Natura 2000 areas, the methods developed will also be applicable within other management practice, e.g., the future third generation water plans.

Bruno Ibanez ErquiagaBruno Ibanez-Erquiaga

Title of PhD project

The importance of oil and gas platform foundations for a key commercial species, the Atlantic cod 

Supervisors 

Jon C. Svendsen, Henrik Baktoft and Jens Kjerulf Petersen

Background of PhD project

There is growing evidence that oil and gas platforms may provide productive habitats for fish communities, partly because of reef effects associated with the foundations, but also because the areas within and surrounding the platforms may act as de facto marine protected areas with limited or no ongoing fishing. For example, the Atlantic cod (Gadus morhua), which constitutes an important target for North Sea fisheries, but its populations are considered to stand below sustainable thresholds, have been preliminarily associated with these structures. However, there is still a poor understanding of the mechanisms behind platforms’ effects and scarce assessments of the ecological outcomes in relation to fish ecology and fisheries. This makes it difficult to predict possible fisheries scenarios associated with different decommissioning and abandonment options. 

About the project

The project aims to provide an understanding of the role that platforms are playing for fish and fisheries in the Danish North Sea, using cod as a case study. The experimental approach involves estimating catch variation along distance-to-platform gradients, and spatiotemporal 3D mapping of cod individuals nearby an oil platform. This knowledge seeks to inform decision-making processes related to platform decommissioning in the North Sea by evidencing how these structures are acting as artificial reefs, potentially providing refuge and substrate to different species.  

Perspective

We expect to evidence the potential importance of oil and gas platforms for Atlantic cod in the Danish North Sea. Considering that fishing is banned within 500m around the platforms, these structures could be functioning as fish sanctuaries and fish hubs, supplying juvenile fish to other areas of the North Sea. Provided the intense trawling in the North Sea, platform decommissioning could contemplate a partial scheme in which some structures are left to provide refuge for fish communities. Our information will help in the design of future decommissioning and abandonment plans.

Satish PawarSatish Pawar

Title of PhD project

Habitat suitability and potential recovery of eelgrass.

Supervisors

Karen Timmermann and Jens Kjerulf Petersen

Background of project

Eelgrass is one of the common aquatic vegetation in the northern temperate coastal regions. It provides valuable ecosystem services like nursery grounds to juvenile fish, improve water quality and sequester carbon as green biomass. The eelgrass meadows in Danish coastal waters were damaged due to stone fishing and frequent eutrophication episodes. These activities have been discontinued and water quality has improved over the last decade. However, the eelgrass has not recolonized the previously occupied habitat sites. Understanding the factors affecting eelgrass recovery is primary task in eelgrass habitat restoration and future management.

About the project

The eelgrass growth could be affected from local disturbances along with global phenomena of climate change. This project aims to understand the combined effect of these factors affecting eelgrass recovery. This will be achieved by combining the monitoring data of eelgrass environment and habitat suitability modelling techniques. Continuous satellite data will provide spatial habitat variables like light availability, turbidity and Sea Surface Temperature (SST) of shallow waters. The habitat suitability analysis will be performed by implementing the eelgrass growth model with spatial habitat data along with correlation-based niche models to spatially map potential habitats. The growth models can simulate climate change scenarios to evaluate effect of eutrophication and increased water temperature.

Perspective

Combining satellite data and modeling will provide new knowledge on shallow water environment in Danish coastal waters. The project will contribute significant insight into the combined effect of eutrophication and climate change on eelgrass health. From the spatial outputs of habitat suitability, eelgrass zones for potential recovery can be identified for their management. The information obtained from spatial simulations can aid in planning restoration activities and forming policies for eelgrass conservation.

Previous PhD students (since 2020)


Tim Wilms

Restoration and non-invasive monitoring of geogenic reefs in temperate waters
Go to DTU Orbit to download thesis

Peter Søndergaard Schmedes

Investigating hatchery and cultivation methods for improved cultivation of Palmaria palmata
Go to DTU Orbit to download thesis

Daniel Taylor

Mitigation culture of mussels: Production and ecological impacts
Go to DTU Orbit to download thesis