The Scottish Pelagic Processors Association (SPPA), which represents all major Scottish mackerel processors, has welcomed the news.
It has been campaigning for recognition of the sustainable fishing practices employed by European and Norwegian fleets since mackerel was downgraded in January this year.
Francis Clark, board member of the SPPA, said: “We welcome today’s decision by the MCS to reclassify mackerel caught by members of the European and Norwegian fleet in recognition of our commitment to work together to safeguard the long-term sustainability of the stock.
“We also applaud the MCS’s decision to classify mackerel caught by Icelandic and Faroese trawlers with a red four, which means people should avoid eating it.
“As part of MINSA (Mackerel Industry Northern Sustainability Alliance) we are working with the International Council for the Exploration of the Seas and a number of scientific bodies to better understand stock levels. Last year all member countries agreed to reduce our quota by 15% in line with advice.
“Eating oily fish has tremendous health benefits. Our aim is to make sure people across the UK have access to the most sustainable sources of mackerel available.
“As an industry body we also want to safeguard the livelihood of the mackerel fishing and processing industry in the UK. The species is worth £324m to the economy and supports over 2,200 jobs.”
Dr Paul Williams, chief executive of Seafish said: “The MCS’s decision to upgrade the sustainability rating of UK mackerel is another positive step in the right direction for the seafood industry in the UK.
“The MCS Good Fish Guide can provide a useful tool to help consumers make responsible choices when buying fish.
“Although mackerel’s MCS rating was downgraded five months ago, it is important to recognise that science and the fishing industry are in agreement that stocks of mackerel are plentiful at present.
"The issues have been driven by disputes between various parties fishing the North east Atlantic stock, most notably due to the increase in Icelandic and Faroe Islands mackerel catches.”