Aquaculture plant

PhD defense about microbial water quality in aquaculture

Monday 26 Feb 18


Paula Andrea Rojas-Tirado

Time & Place

Thursday 1 March 2018, 11.00 a.m.

The auditorium at North Sea Science Park Auditorium, Hirtshals. 

The thesis

A copy of the thesis "Microbial Water Quality within Recirculating Aquaculture Systems" is available for reading at the institute. Please, contact Rikke Hansen,

The reuse of water in recirculating aquaculture systems increases the risc of impaired water quality. PhD Student Paula Andrea Rojas Tirado has investigated new methods for monitoring bacterial activity. On 1 March she will defend her thesis.

The rapid expansion and success of recirculating aquaculture systems requires continuous development of new knowledge to address ongoing challenges. One of these challenges is the resulting water quality; when fish production in reused water becomes more and more intensified, requirements of treatment processes increases. Similarly, this also calls for measures to assess that the water quality fulfils optimal rearing conditions. 

In her PhD project, Paula Andrea Rojas-Tirado, DTU Aqua focussed on new methods to evaluate bacterial abundance and activity in recirculating fresh water aquaculture systems rearing rainbow trout. The studies included two new quantitative measures to access bacterial activity (Bactiquant® and Hydrogen Peroxide Degradation assay) and flow cytometry to enumerate particle-bound and planktonic bacteria.

Overall the studies show that the methods are useful indicators to assess bacterial abundance and activity, and it is suggested that these tools are included in operational use in recirculating aquaculture systems.

About the defence

Paula Andrea Rojas-Tirado will defend her thesis ”Microbial Water Quality within Recirculating Aquaculture Systems" on Thursday 1 March 2018, 11.00 a.m. in the auditorium at North Sea Science Park Auditorium, Hirtshals. 


  • Principal supervisor: Senior Researcher Lars-Flemming Pedersen, DTU Aqua
  • Co supervisor: Head of Section Per Bovbjerg Pedersen, DTU Aqua


  • Senior Researcher Anne Johanne Dalsgaard, DTU Aqua
  • Assistant Professor Kari Attramadal, NTNU, Norway
  • Associate Professor Marc Verdegem, Wageningen University, The Netherlands

Chairperson at defence

  • Postdoc Carlos Octavio Letelier-Gordo, DTU Aqua
20 OCTOBER 2020