A decision not to pursue a prosecution for a major diesel spill has been described as “devastating” for the fishermen who lost work as a result.

Ashley Jones, of Selwyn’s seafood, said cockle pickers lost as much as £15,000 of income after the Llangennech rail wagon derailment in August 2020.

Ten wagons derailed and hundreds of tonnes of diesel spilled into the Loughor Estuary in Carmarthenshire.

Natural Resources Wales said there was insufficient evidence for a conviction.

“It would be a reckless use of public monies to pursue a prosecution,” the environmental body said.

The train was pulling the wagons from Milford Haven, Pembrokeshire, to Theale, near Reading, on 26 August 2020.

Cockle and shell fisheries in the area were closed for eight weeks after the spill, so that the shellfish could be tested for contamination.

Mr Jones, who owns of Selwyn’s seafoods, explained that the closure took place in “peak season for cockle gathering,” resulting in pickers losing up to £15,000, around a third of their annual income.

He said that some of the fishermen had to borrow money from Selwyn’s, and others didn’t return to the industry.

In order to keep up with customer demand, Selwyn’s had to import cockles from other areas, Mr Jones said, which “came at a cost” to the business.

He said that the decision by Natural Resources Wales not to pursue a prosecution was “devastating for the fishermen.”

The cocklers are looking into legal action of their own, but Mr Jones said it would likely cost a lot with little result, and he doubted the fishermen or the company would be able to afford to go any further.