Ghost gear: The dangerous killer lurking in the sea
Lost fishing gear, also known as ghost gear, is one of the biggest killers lurking in our oceans.
Nets, long lines and pots are often lost or abandoned just off our coast, trapping marine life for decades and condemning it to death.
Some 640,000 tonnes of fishing gear is lost at sea every year and one of the places affected is the conservation area of Milford Haven in Wales.
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Milford Haven is on the north side of the Milford Haven Waterway, an estuary forming a natural harbour that has been used as a port since the Middle Ages.
But underneath the sea's surface, there are all sorts of plastics, including abandoned lobster pots and fishing nets.
It is estimated that some 58% of all plastic in the ocean is ghost fishing gear.
Divers are trying to remove the pollution off Milford Haven.
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It is a time consuming process but they also know it is an important one.
Dave Kennard, one of the divers, said: "Birds are dying from fishing nets. ropes that are lost.
"They are just hanging themselves on the rock face."
:: Sky's Ocean Rescue campaign encourages people to reduce their single-use plastics. You can find out more about the campaign and how to get involved at www.skyoceanrescue.com
:: And at 8pm you can watch our documentary A Plastic Whale, which this week was awarded a special prize at the Monte Carlo TV festival.