European eel larva swimming in a Kreisel tank. Photo: Sune Riis Sørensen.

PhD defence on bacterial management in European eel offspring culture and immune system development in early larval stages

Friday 01 Dec 23


Kasun Anuruddha Bandara
PhD Student
DTU Aqua
+45 93 51 06 10


Jonna Tomkiewicz
Senior Researcher
DTU Aqua
+ 45 40 21 03 56


This PhD was funded by the Nordic Five Tech Alliance and funds offered by DTU Aqua and the Department of Biotechnology and Food Science at NTNU.

On 11 December 2023, Kasun Anuruddha Bandara will defend his PhD thesis. The defense can be followed online or attended in person at DTU Hirtshals Campus.

The European eel population is under pressure. It’s classified as "critically endangered", and the International Council for the Exploration of the Sea recommends a complete cessation of eel fishing.  

If we are to preserve the eel as a food fish, a sustainable solution would be to farm it in aquaculture. However, establishing hatchery technology for breeding European eel in captivity has proven to be a significant challenge. The eel's life cycle is complex, and there is still a distinct lack of knowledge about the eel’s reproduction and early life history in nature. 

Research over several decades has created progress in broodstock rearing, assisted reproduction, artificial fertilization and egg quality, as well as the culture of the early life stages. Now, research focuses on extending the survival and further development of eel larvae to reach the glass eel stage.

In his PhD project, Kasun Anuruddha Bandara, DTU Aqua, has focused on the interaction between the bacteria in culture systems and eel offspring, concurrently investigating how the immune system of the larvae develops and functions under culture conditions.

The project includes four studies based on controlled experiments. Together, they have investigated how different treatments and culture conditions in captivity affected the composition of bacterial communities and the development and survival of the eel larvae, while molecular studies of gene expression have provided new knowledge about the immune system development in the early life stages of European eel. 

The thesis concludes that the gained insights can contribute to improving offspring-rearing protocols, but it also emphasizes the need for further research, among other things, to further elucidate the microbial dynamics in feeding larval culture.

The PhD study was conducted in collaboration between DTU and The Norwegian University of Science and Technology (NTNU), leading to a double degree. 

About the defence

Kasun Anuruddha Bandara will defend his PhD thesis "Marine larval hatchery technology: Microbial management and immune system ontogeny in European eel" on Monday, 11 December 2023, at 13:00. The defence can be followed online or at DTU Hirtshals Campus.


  • Principal supervisor: Senior Researcher Jonna Tomkiewicz, DTU Aqua
  • Co-supervisor: Professor Olav Vadstein, NTNU, Norway
  • Co-supervisor: Researcher Sebastian Nikitas Politis, DTU Aqua


  • Senior Researcher Manuel Gesto, DTU Aqua (Chair)
  • Senior Research Scientist Catriona Clemmesen, GEOMAR Helmholtz Centre for Ocean Research, Germany
  • Assistant Professor Fotini Kokou, Wageningen University, Netherlands

Chair at the defence

  • Senior Researcher Sanni-Leea Hellevi Aalto, DTU Aqua

A copy of the thesis is available for reading at DTU Aqua. Please contact PhD Coordinator Susan Zumbach Johannesen,

How to attend the defence

In person

Everybody is welcome to attend Kasun Anuruddha Bandara’s PhD defence in person at DTU Hirtshals Campus, Willemoesvej 2, 9850 Hirtshals.



The defence can be followed online. Please sign up for the online defence by e-mailing to Sune Riis Sørensen,



Monday, 11 December 2023, 13:00-16:00