New undersea technology could help stop ‘ghost nets’ damaging aquatic life

New technology could be used to protect marine life from pollution by locating and retrieving lost nets and fishing gear which can drift around the oceans for years.

Known as “ghost nets”, they are a major threat to sea life, choking coral reefs, damaging habitats, trapping fish, birds and mammals, as well as getting tangled on propellers.

The nets, often lost during storms and sent adrift for long distances on currents, are also a source of pollution as they slowly break up, adding to the volume of micro-plastics in our seas.

Now experts from Newcastle University say the NetTag project could help by using low-cost transponders attached to the fishing gear which will allow it to be located if it goes adrift.

The match box-sized transponders, which could cost as little as £100 to locate nets worth many thousands, could be a “win-win” for fishermen and the environment, the developers believe.

As well as being low-cost, another key parts of the breakthrough is that the technology will have very low power consumption, meaning its battery could last for months in the water.

And unlike the “black box” transponders used in aeroplanes, the new technology will only reply with a low volume “ping” when it picks up a tracking signal within its range, meaning sealife will not be constantly disturbed by the devices.

Once located, fishermen could try to recover the nets themselves, or the fisheries authorities could be brought in to use underwater robotic technology to collect the marine litter in hard-to-reach places.

They could also be used by divers to tag litter they see in the ocean, so it can be retrieved later.

Jeff Neasham, senior lecturer in the School of Engineering, said: “We want to achieve a win-win scenario where modest investment by fishermen can be more than paid back, by avoiding the loss of valuable assets, while also significantly reducing a major source of plastic pollution in the marine environment.”

Mr Neasham added: “These devices don’t sit there and transmit continuously, making a racket all the time; they sit and listen and they only talk if a unit on the surfaces accesses them to talk.

“We are not creating a big environmental problem with noise emissions – they will only talk if someone is in range searching for them.”