Søl. Foto: Peter Søndergaard Schmedes.

PhD defense on seaweed cultivation

Tuesday 19 May 20


Jens Kjerulf Petersen
DTU Aqua
+45 35 88 31 71


Peter Søndergaard Schmedes
DTU Aqua
+45 93 51 18 98

On 25 May 2020, Peter Søndergaard Schmedes, DTU Aqua will defend his PhD thesis. Due to the corona pandemic the defense will take place online.

The edible, reddish seaweed species dulse has high nutritional value and is a good source of vitamins, minerals and proteins. Dulse, Palmaria Palmata, can be used for both animal feed and human food.

There are limited quantities of wild dulse, but it is can be cultivated in aquaculture. So far, the cultivation methods have not been suitable to sustain a large commercial cultivation which is a bottleneck to meet the growing demand.

Peter Søndergaard Schmedes and his colleagues have investigated the possibilities of optimizing the sea-based and land-based grow out of dulse. His research has covered the entire process from inducing the formation of spores in the adult individuals and spore release and settlement in the hatchery, over the development of seedlings and grow out. Among other things, they have developed new methods to improve spore attachment on cultivation media, such as nets and ropes, which have proven promising in optimizing the efficiency of seedling production, which is crucial in reducing costs. The new methods could be used to extend the seedling production season.

The cultivation experiments showed that dulse grow well in the inner Danish waters and in land-based tanks. This indicates that the Danish dulse is adapted to the relatively low salinity. The fact that the seedlings were larger at release showed a positive effect on the biomass yield, as did the larger plants more easily avoid bio-fouling by other marine organisms during the cultivation phase.

The new hatchery methods developed show to increase the efficiency in seedling production which can sustain a large hatchery production. Dulse biomass was cultivated and harvested in Inner Danish waters and from a land-based tank setup.

About the defense

Peter Søndergaard Schmedes defends his PhD thesis "Investigating hatchery and cultivation methods for improved cultivation of Palmaria palmata" on Monday, May 25, 2020 at 13.00 via Zoom.

Contact Rikke Hansen, rikh@aqua.dtu.dk no later than 25 May, at 10.00 to get a link to join the defense.

  • Main supervisor: Professor Jens Kjerulf Petersen, DTU Aqua
  • Co-supervisors: Researcher Mette Møller Nielsen, DTU Aqua and Kjell Inge Reitan, NTNU
  • Professor Charlotte Jacobsen, National Food Institute, DTU
  • Professor Michelle Stanley, SAMS, Scotland
  • Chief Scientific Officer Stafan Kraan, The Seaweed Company, Ireland
Chair person at Defense
  • Senior Researcher Camille Saurel, DTU Aqua