Introducing the World’s First Fully Automated Sex Sorting Machine for Salmon Smolt

12. August 2025 · Ukategorisert

GreenFox Marine has developed the world’s first fully automated machine for sex sorting and health screening of salmon smolt. The technology combines ultrasound, optical image analysis and artificial intelligence to enable better decision-making, improved fish welfare and more sustainable production.

The solution has secured GreenFox Marine a nomination for the 2025 Innovation Award, which will be presented during Aqua Nor.

Ultrasound, image analysis and artificial intelligence

The new sex sorting machine is an improvement of GreenFox Marine’s existing semi-automated system, which is already in use on the market. In the new version, the entire sorting process is automated and integrated directly into the vaccination process.

The machine uses ultrasound to capture images of the fish’s gonads while the fish is anesthetized for vaccination. A proprietary AI-based analysis tool interprets the ultrasound images and determines the sex – entirely automatically.

— The machine is directly integrated into the vaccination line and enables efficient and gentle sorting with no manual handling, while fully safeguarding fish welfare, says Eivind Leirvik Nergaard, biotechnologist at GreenFox Marine.

In addition to sex sorting, the machine detects both internal and external health anomalies using ultrasound and optical image analysis.

— The image analysis gives us detailed, individual-level data on each fish, providing better insights for desicion-making in production. It allows early detection of injuries and disease, right from the beginning of the life cycle.

Sex sorting improves growth conditions for the fish

In Norway, it has traditionally been common to release smolt without sex sorting, as the process has been both time-consuming and expensive.

— In Chile, for example, sex sorting has been done manually for more than 20 years using handheld probes – a process that is very time-consuming, Eivind explains.

— Sex sorting methods simply haven’t been efficient enough. Our aim is to make sex sorting a simple, natural part of the production process – without adding extra steps.

Early sex sorting gives better control and more profitable batches, as male and female fish have different needs and growth trajectories.

— Males tend to mature earlier and can be harvested sooner, before health declines and quality is reduced. Females generally show greater robustness in the final seawater phase and benefit from a longer grow-out period to gain more weight and achieve better fillet yield, Eivind explains.

— Sex sorting also helps reduce stress and competition that often occurs in mixed farms, which in turn lowers the risk of injuries and wounds. Our experience shows that sex-sorted fish are more resilient, have lower mortality, and grow faster and steadier.

Aiming for a new industry standard

GreenFox Marine hopes the machine will establish a new standard for how sex sorting and health screening are carried out in aquaculture.

— Authorities have made it clear that fish mortality must be reduced. Our fully automated sex sorting machine contributes directly to this goal by combining sorting and early health detection in a single step. The technology paves the way for improved fish health practices – with lower mortality, higher profitability, and more sustainable production, Eivind concludes.