In the mid-20th century, fish processing plants relied heavily on manual labor. Workers used knives to gut, fillet, and trim fish, sorted catches by size and species, and removed scales with handheld tools. These tasks required strength, dexterity, and experience. At Norwegian salmon plants during the 1970s, dozens of workers would stand shoulder to shoulder, gutting fish on tables, often producing inconsistent results.
Human fatigue, haste, and differences in skill levels led to uneven fillets, damage to muscle tissue, and higher amounts of waste.
The first industrial machines gradually appeared to address these inefficiencies. Early gutting and heading machines mechanized repetitive steps, but their performance was limited. For instance, Baader 142, developed by the German company Baader, became widely used for salmon and trout. It could automatically measure fish size and perform a “princess cut” to remove entrails with vacuum assistance and throat incisions. Yet, the system still required manual loading and adjustments. The quality of processing varied, particularly with fish at the edge of the weight spectrum or with unusual body shapes.
Today, new generations of machines integrate advanced technology to replicate the precision of skilled workers — but with unmatched consistency and speed. These systems combine sensors, robotics, and digital controls to gut, fillet, debone, and package fish at industrial scale.
Machines like Marel’s MS 2750 filleting system or RoboBatcher Thermoformer process fish with accuracy, improve yield, and minimize manual rework. Modern technology has redefined the economics of fish processing, reducing costs, waste, and labor intensity.
Early Industrial Fish Processing Machines
The first wave of industrial machines introduced mechanical aids for gutting, scaling, and filleting. Baader, founded in Lübeck in 1919, became a pioneer by developing purpose-built machines for herring, cod, and salmon. The Baader 142 salmon gutting machine, introduced in the 1980s, was capable of handling 16 fish per minute within the 2–7 kg range. It measured fish length mechanically and performed standard incisions with a rotating knife set.
Despite their value, these machines had clear drawbacks. Operators needed to intervene frequently, either to clean the system, correct miscuts, or remove remaining entrails. Flexibility was minimal — switching species required mechanical adjustments. Yield often lagged behind manual cutting, with losses accumulating across tons of fish. Nonetheless, these machines set the foundation for industrial automation in fish processing.
Modern Processes and Technologies
Advancements in engineering, electronics, and software have produced machines that dramatically improve fish processing. Marel MS 2750, for example, incorporates servo-controlled blades that adapt in real time to the contours of each salmon or trout. The machine uses imaging systems to determine exact cutting paths, minimizing waste and increasing yield. By reducing manual trimming, it improves consistency across fillets.
For packaging, Marel’s RoboBatcher Thermoformer uses robotic arms to place fillets into trays with precise weight control. Capable of handling up to 120 portions per minute, it not only increases throughput but also reduces “giveaway” — the excess product weight beyond target specifications. Meanwhile, Marel RoboOptimizer aligns fillets before portioning, ensuring cuts follow optimal lines for both presentation and yield.
Baader has also modernized its lineup. The updated Baader 142 gutting machine now processes not only salmon but also farmed cod, supporting Norway’s expanding aquaculture sector:
Coupled with Baader’s 144 Gut Inspection System, which uses vision technology to check cleaning quality, the machine closes the loop by integrating real-time quality control.
Materials and Engineering Solutions
Fish processing environments are harsh: constant exposure to saltwater, high humidity, low temperatures, and organic matter accelerates corrosion. As a result, manufacturers rely on austenitic stainless steels such as AISI 304 and AISI 316L, known for their resistance to chlorides and ease of cleaning. Surfaces are polished to reduce bacterial adhesion and designed with smooth welds to meet sanitary standards such as those of the European Hygienic Engineering & Design Group (EHEDG).
Modern machines also incorporate lightweight alloys and modular components. This reduces power consumption, eases maintenance, and extends service life. Additive manufacturing (3D printing) is emerging in prototyping replacement parts, though regulatory acceptance is still developing in food-contact applications.
Automation, Robotics, and Artificial Intelligence
Robotics and computer vision have transformed fish processing. Marel and Baader now integrate camera systems, X-ray scanners, and machine learning algorithms to adapt processing to individual fish. Vision-guided robots can identify bones invisible to the human eye and adjust blades dynamically. Baader’s 144 Gut Inspection System automatically detects leftover entrails and diverts fish for reprocessing. Marel’s Innova software suite collects data across production lines, enabling predictive maintenance, yield tracking, and optimization of machine settings. Machine learning models are trained on thousands of fillets to recognize optimal cut lines and predict defects.
These systems reduce the dependency on skilled labor, which has become scarce in many processing regions, while ensuring compliance with strict food safety standards.
Sustainability and Efficiency
Modern technology has also advanced sustainability in fish processing. By improving cut accuracy, machines recover a higher percentage of usable fillet. In salmon processing, yield improvements of 1–2% translate into millions of dollars annually for large plants. Automation reduces water use by integrating closed-loop cleaning systems and lowers energy consumption through optimized motors and drives.
By-products such as heads, viscera, and backbones can now be collected more cleanly for use in fish oil, meal, or nutraceuticals. For example, Hofseth Processing in Norway partnered with Baader to adapt gutting machines for farmed cod, ensuring by-products like liver could be retained for value-added use.
Case Studies of Implementation
At Norwegian salmon processor Hofseth, upgrading to Baader’s cod-adapted 142 machines enabled the company to diversify beyond salmon without major increases in labor costs. The machines ensured consistent gutting at high throughput while recovering more by-products for secondary markets.
Icelandic companies using Marel’s MS 2750 filleting systems reported reductions in manual trimming labor by up to 40% and higher average fillet yields compared to older equipment. Marel’s RoboBatcher has been deployed across Europe and North America, enabling processors to meet supermarket demands for fixed-weight packages with minimal product giveaway.
Challenges and Future Directions
Despite progress, several challenges remain. Capital costs for high-end machines are substantial, creating barriers for small processors. Machine learning systems still struggle in extreme environments — condensation, low light, and slime can distort vision sensors. Skilled technicians are required to maintain and calibrate these complex systems.
Looking forward, fish processing is likely to see deeper integration of IoT connectivity, enabling remote monitoring and service. Advances in X-ray inspection — already widely deployed in fish processing — continue to improve bone detection and quality control; ultrasound is being explored in research (e.g., HIFU) to weaken pin-bone attachment rather than for mainstream in-line bone detection.
Autonomous cleaning systems are being tested to reduce downtime and manual sanitation work. Materials research is ongoing to create steels and coatings even more resistant to saltwater corrosion.
Modern technology has already shifted fish processing from labor-intensive, inconsistent work into a data-driven, high-precision industrial practice. The trajectory suggests machines will continue to evolve toward fully autonomous, flexible systems that maximize yield, ensure safety, and reduce environmental impact.