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Scientists have successfully trialled a method of finding examples of ‘ghost fishing’ and other lost creel gear in Scottish seas, as they attempt to reduce the risk of marine mammal entanglement.

Ghost fishing refers to lost fishing gear like creels that can collect on the seabed and continue to fish without ever being collected. Rope associated with the gear can also become an entanglement hazard. It is estimated that in Scottish waters approximately six humpback whales and 30 minke whales become entangled in active creel fleets each year, but the numbers that succumb to lost creel gear remains unclear.

Researchers at SAMS, a partner of UHI, have led a pilot study looking at ways of finding lost gear in coastal waters of Argyll, with a view to removing it from the sea.

The �鶹ӰԺteam used a boat to tow a side-scan sonar system, known as a towfish, which emits high-frequency sounds and records corresponding echoes, to locate objects they believed to be creels. They then deployed a remotely-operated vehicle (ROV) to observe the objects in detail and record footage of what they had found.

Tests were originally carried out on active creeling fleets and test creels to help researchers recognise the shape and size of the gear they would be looking for. Subsequently, surveys were done in areas where creels had been anecdotally reported, resulting in successful location of multiple derelict creels on the seabed.

The success of the trial paves the way for better monitoring of this marine litter problem, potentially including increased use of underwater robotic vehicles in known hotspots to reunite fishermen with their gear.

Lead scientist Dr Steven Benjamins of �鶹ӰԺsaid: “There are lots of reasons why creel fishing gear becomes lost, such as storms or interactions with other fishers and large vessels, and these are largely outwith the control of fishermen. This also can put a considerable financial burden onto them.

“The gear is sometimes found but we suspect that a lot of it is lost to the ocean; we wanted to know if we could find it.”

While the study has shown an effective way of identifying lost creel fishing gear, Dr Benjamins said there was more work to be done to establish the extent of the problem.

He added: “As well as being an entanglement risk, these creels continue to ‘ghost fish’, meaning prawns and other species continue to become trapped in the creels. The equipment can also become a navigational hazard.

“Finally, as the gear degrades, it releases microscopic plastic particles into the sea which end up in our seafood and the wider marine environment. These are all good reasons to try and reduce the amount of lost fishing gear in the sea.”

This project was supported by the Scottish Marine Environmental Enhancement Fund (SMEEF). �鶹ӰԺhas published a final project report, available .