Jonathan Demmer ECR-TG - EGU General Assembly 2019
The PRIMaRE Early Career Travel Grant enabled to travel to the EGU General Assembly 2019, in Vienna. This is the 17th EGU conference and is held every year in Vienna at the Austria Center Vienna. This international conference aim is dedicated to the pursuit of excellence in the Earth, planetary and space science for the benefit of the humanity worldwide. EGU provides the opportunity to more than 16000 scientists from 113 countries to discuss and exchange knowledges on a wide diversity of scientific field.
The work I presented was entitled “Can offshore wind farms impact mussel settlement in the Irish Sea?”. My PhD focuses on the impact of physical (tides, wind, temperature…) and biological (vertical migration, mortality, age of settlement…) processes on mussel larvae dispersal (mytilus edulis) in the Irish Sea. Shellfish aquaculture in UK is dominated by mussels farming which depends on the harvest of wild mussel spat. The first results of the model showed that a proportion of mussel larvae (between 15% to 20% depending on the tide) are carried away from their native mussel bed to an area where the wind farm are implanted. In this state of mind, the wind farm represents a potential site of interest for mussel larvae settlement.
The presentation described the different stages from the creation of a hydrodynamic model of the Irish Sea to the visualisation of particle dispersal. Indeed, for the conference I created a fine resolution grid (30 meters) of the Irish then ran a 2D model for 2 months with a 30 min output. The model was then validated using two methods: Tidal analysis and water elevation. The tidal analysis was made on five different tidal constituents using a Matlab code (T-tide) and results show that the model error reach 6.8 %. For the water elevation, the Root Mean Square Error (RMSE) reaches 3.27 % which represents a difference of 30 cm. View to the results of validation, the model can be used to predict the larvae dispersal. The Particle Tracking Model (PTM) created on Matlab show that the mussel dispersal is both area and tide dependent. Furthermore, offshore wind farms allows connectivity among mussel populations which never met before. This result highlights the importance of human offshore structure on populations dynamic in both positive and negative ways.