Newsletter March 2026

Progress in breeding eel larvae
In this newsletter we summarize the progress we have made in recent times (as of 2024) with three components of breeding: egg hatching, prelarval survival (up to 14 days) and survival from 14 to 42 days (see the graphs in the pdf version of this newsletter). Each graph also shows the long-term goals needed to switch to commercial production.
The graphs show that the hatching rate of the eggs is already starting to get pretty close to the final goal, and the survival in the first 14 days is also coming well in the direction. But in 2025 we did not have good results with the survival between 14 and 42 days; we were even lower last year than in 2024. This is probably caused by biological variation of the mother eels. We have not yet achieved the necessary consistency. But by all appearances, an improvement has set in as of early 2026.
In consultation with the Supervisory Board, we have now agreed on more realistic (achievable) quarterly targets. And to minimize variation and the chance of unpredictable setbacks, we are focusing research on some additional spearheads:
- Investment in an additional egg incubation system so that we can experiment with the conditions under which the eggs hatch.
- Use of an (external) pond facility in which (wild) mother eels stay for a time to achieve consistent quality as much as possible.
- Strong attention to the method of disinfection when culturing larvae older than 14 days, so that the high mortality we see around day 30 can be improved.
- Exploration of innovative techniques to intensify breeding using robotization and artificial intelligence.
We are grateful to all shareholders of Glasaal Volendam R&D for their continued support and we ask for your patience. Getting a fish into aquaculture is no small feat. Even with well-researched species that many groups around the world are working on, such as turbot and sole, it has taken 20 years. We are confident that we will succeed with the European eel as well, but it is a matter of long breath and perseverance.