Mackerel from the Northeast Atlantic is no longer considered a sustainable seafood option, according to the Marine Conservation Society (MCS), the Guardian reported.

Once considered a responsible choice, the species has suffered from consistent overfishing, the NGO said.

Mackerel is harvested in the Northeast Atlantic by Norway, Iceland, the Faroe Islands, and the UK. Since 2009, total allowable catches agreed upon by all parties have consistently exceeded the scientifically recommended levels by a margin ranging from 5-80%. From 2020 to 2024, TACs were, on average, 39% above the scientific recommendations, according to MCS.

The organization's latest Good Fish Guide downgraded mackerel caught by midwater trawling from "okay" to "avoid," urging retailers and restaurants to stop selling it. Even mackerel caught using the more selective hook and line method has been downgraded in the guide.

Alice Moore, manager of the Good Fish Guide at the MCS, called the situation "deeply concerning."

"We’re witnessing a steady decline in numbers, and they are nearing a breaking point. Immediate action must be taken by the UK government to work with other nations to align catch limits with scientific advice," she said.

Consumers are instead encouraged to choose alternatives like North Sea herring or Cornish sardines. Meanwhile, monkfish from the North Sea have improved to a top sustainability rating, and blue marlin has been removed from the red list.