Supertrawlers spent almost 3,000 hours fishing in UK marine protected areas in 2019, making “a mockery of the word ‘protected’,” according to campaigners.

Supertrawlers are those over 100 metres in length and can catch hundreds of tonnes of fish every day, using nets up to a mile long. A Greenpeace investigation revealed that the 25 supertrawlers included the four biggest in the world and fished in 39 different marine protected areas (MPAs).

The Southern North Sea MPA was one of those fished and was created to safeguard porpoises, which are especially threatened by supertrawlers. More than 1,000 porpoises died in fishing nets around the UK in 2019. The most heavily fished MPA was the Wyville Thomson Ridge, off Shetland, which was intended to protect reefs. All the supertrawler fishing was legal.

Forty per cent of England’s seas are designated as MPAs, but these only ban some of the most damaging activities in some locations. On Monday, an independent review commissioned by the government urged the establishment of highly protected marine areas (HPMAs), where all harmful activities including fishing, dredging and construction are banned. The government’s own assessment in 2019 showed the marine environment is not in a healthy state.

“Our government allowing destructive supertrawlers to fish for thousands of hours every year in MPAs makes a mockery of the word ‘protected’,” said Chris Thorne of Greenpeace UK. “For our government to be taken seriously as a leader in marine protection, it must ban this practice.”

Britain’s most valuable fish stock has lost its sustainable status after overfishinghas driven mackerel stocks to the brink of collapse.

As of this weekend, the Marine Stewardship Council (MSC) has warned people against purchasing mackerel caught in the North East Atlantic, which will no longer bear its “blue label”.

The body charged with assessing the health of wild fisheries said its decision came after stocks had crashed due in part to quotas that exceeded the best scientific advice. 

Accounting for around a third of the seafood landed in the UK, the mackerel fishery is worth over £200m.

“This news will be a disappointment for the fishermen as well as for mackerel loving consumers,” said Camiel Derichs, Europe director for the MSC.

“However, factors including declining stocks, quotas set above new scientific advice and poor recruitment have combined to mean that the fisheries no longer meet the MSC’s requirements.”

The International Council for the Exploration of the Sea (ICES) states that mackerel populations have been in freefall since 2011, dropping from a high of 4.79 million tonnes to 2.75 million tonnes last year.

Council experts advised that current catches must be cut by over two thirds to allow the stock to recover to a sustainable level over the next two years.