Seine netting is among the most cost-efficient and sustainable commercial fishing methods, but it comes with its own set of challenges.
Managing such a large net over long distances is one of them. Especially when we’ve got strong tides to deal with, in the middle of the busiest waterways on the planet. This is exactly what the crew of the 24m Scottish vessel Acionna GK44 was facing. Factors like vessel speed, tide conditions, and chain weight – aside from the net itself – all influence how effectively fish are caught.
So, how can you tweak your setup to ensure a good haul? The compact CatchCam & SeaSensor systems might just be the answer.
Improving Catch Efficiency with Camera and Sensor Technology
In fishing, not knowing what’s happening underwater means costly guesswork. Traditionally, skippers rely on their experience, tides, and seasonality to predict good fishing conditions.
However, as any seasoned fisherman will tell you, fishing can make a fool of us all. Not seeing the full picture can mean the difference between coming back home empty-handed or with a great haul.
Underwater cameras like CatchCam provide a valuable look into the action, capturing visual evidence of how the gear and catch are behaving, but they don’t tell the whole story—especially in deeper or turbulent waters. This is where SeaSensor fills the gap. Mounted on the headline, it captures accurate data on net depth, movement, water temperature, and turbidity, providing a fuller picture of what’s happening underwater.
Net-Mounted CatchCam Systems
Seine netting might seem straightforward, but the reality is it requires an enormous amount of skill and concentration, much more so than demersal trawling, dare we say it! While both methods use similar nets, the way they operate is completely different. In seine netting, the vessel shoots a long rope in a wide circle around the fish, followed by the net itself. Then, as the rope is hauled in, it guides the fish into the net.
Variables such as tide conditions, seabed obstacles, vessel speed, and rope coiling all influence how well the net performs. Skippers must make constant calculations to ensure optimal net shape and positioning to maximise their catch while avoiding gear damage or loss.
On the Acionna, which targets prime demersal and non-quota species, our aim was to build an understanding around how every factor affected the fishing operation. For this commercial deployment, the team fitted:
- Three CatchCam cameras strategically positioned around the net,
- One SeaSensor, mounted at the centre of the headline to measure net height and movement, along with the water temperature and turbidity.
The trial took place over two days, first targeting squid in the East English Channel, then shifting to prime demersal fish much further west, off of Lyme Bay. As the vessel moved through different waters, the combined CatchCam footage and SeaSensor data helped track net drag, shape and even fish movement throughout the haul – and into the codend.
"It was interesting to get an exact insight as to what the net is doing, and therefore how the gear needs to be hauled for different target species and particularly different types of bottom."
shared Aaron Brown, skipper of the 24m Seiner Acionna, in an interview with Fishing News.
Collecting Underwater Data aboard the Scottish Seiner
Each deployment provided more insights until, by the end of the trial, a clear picture of the net’s performance emerged:
- Chain weight impacts performance: An 80kg chain attached to the bosom brought the gear to settle within 1 minute of shooting. However, the chain had drawbacks: it slowed the hauling speed, was prone to fraying against the bottom sheet causing wear, and caused the headline to dip – leading to catch loss. On the other hand, without the chain, the net took 8 minutes to sink, drifting far from the target area.
- Net shape varies throughout the tow: For most of the time, the net remains loose and undulating, only reaching full tension toward the end. This is also when fish start entering, and the codend begins to fill. The timing of this could have a significant impact on the catch rate for the haul.
- Fish behaviour and catch timing: Data revealed that fish typically start entering the codend in the final 10 minutes of the tow, staying calm until the net is hauled onboard. That explains why the quality of the catch is so high.
- Speed influences net performance: As vessel and hauling speed fluctuated, the headline height changes, confirming the need to maintain a good steady speed towards the end of the haul.
By integrating sensor data with video footage, the skipper was delighted to see that certain aspects of his gear were working well. Thus, he was now able to focus his attention on the areas that needed improvement, including gear positioning.
SeaSensor Data
CatchCam Footage
CatchCam camera attached to the headline of MFV Acionna.
How CCTech Can Help Your Fishing Operations
This deployment once again reinforced the value of seeing how your gear behaves: whether you’re trawling, potting, or exploring methods like seine netting, understanding gear performance is key to efficiency and sustainability. By integrating visual and sensor data, we help you gather actionable insights that reduce uncertainty and improve your catch efficiency.
At CCTech, we don’t just provide technology—we also offer expert consultancy services to help fisheries optimise operations. Whether you’re looking to monitor net behaviour, reduce bycatch, or enhance gear efficiency, our team can tailor solutions to meet your needs.
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