November 14, 2025

Students Back at Hólar for an Exciting Week Dedicated to Fish Reproduction!​

It was with great enthusiasm and pleasure that we, Camille and Marie, welcomed the students of the Diploma in Aquaculture back to Hólar for a new practicum as part of the Fish Reproduction course. This training week was particularly rich in discoveries, hands-on learning, and scientific exchange, focused on the fascinating mechanisms of fish reproductive biology.
This edition was also marked by the participation of two Master’s students, who joined the practicum to share this experience and further develop their skills.

Full Immersion at the Breeding StationThe week began with a comprehensive visit to the Hólar breeding station. The students had the opportunity to discover the entire production process, from broodstock rearing to reproduction and egg incubation.
A key highlight of the visit: they personally carried out the stripping of both females and males, and the collected eggs will contribute to the station’s official egg stock — a real contribution to the production system!
They also learned to understand many essential technical parameters required for successful breeding: temperature, water quality, broodstock handling, fertilization, and more — hands-on, field-based, real-world experience!

When Science Meets Art
The students then took part in a workshop combining scientific observation and graphical accuracy: scientific drawing of Atlantic salmon specimens at different developmental stages. They first observed the specimens under a binocular microscope, from the newly fertilized egg, through the free-swimming embryo, to the juvenile parr stage.
Based on these detailed observations, they then produced precise scientific drawings, allowing them to strengthen both their observational skills, their scientific rigor, and their ability to visually communicate biological data.
They also learned about the concept of degree days:
This is a tool used to track and predict embryonic development as a function of time and temperature. The warmer the water, the faster the development. In aquaculture, this indicator is essential to anticipate hatching dates, organize batch management, and optimize production.

Dissection, Reproduction, and Sexual Maturity
Another key workshop was dedicated to the dissection of adult Arctic charr, some sexually mature and others not. The objectives were to:
Identify the reproductive organs,
Understand the different stages of maturation,
Link anatomy to reproductive cycles.
A crucial hands-on session to better understand the reproductive biology of fish at the most practical level.

Individual Tracking Using PIT Tags
The students then learned how to insert PIT tags into juvenile Arctic charr. These small electronic tags allow accurate individual monitoring of fish, both in scientific research and in aquaculture production: growth, movement, survival, and performance — a truly essential tool.

Reports, Presentations, and Science in Action
To conclude this intensive week, the students:
Wrote a comprehensive report covering all workshops,
Delivered a group presentation on fish development and sexual maturation.
Meanwhile, the two Master’s students took on an additional challenge:
Presenting and critically analyzing a scientific article related to embryonic development — an excellent exercise in scientific communication and critical thinking.

A Week Full of Learning and Passion
Between hands-on practice, careful observation, scientific reasoning, and teamwork, this practicum week was intense, enriching, and inspiring. Congratulations to all the students for their motivation, curiosity, and professionalism!
We are already looking forward to seeing them again for the next aquaculture adventures at Hólar!