bluefin tuna fish

Tuna and mackerel stocks have fallen by over 70% since 1970 - and a new report has warned the fish species are facing “catastrophic decline” globally.

WWF’s Living Blue Planet report, published this week, concluded many fish species we eat today are “significantly depleted” due to overfishing, destruction of marine habitats and climate change, and could disappear altogether.

The Scombridae family of fish - including tuna, mackerel and bonitos - fell by 74% between 1970 and 2010, with bluefin and yellowfin tuna “of particular concern”, the report noted.

The report - based on a database maintained and analysed by researchers at the Zoological Society of London (ZSL) - found that total fish populations have fallen 50% over the past 30 years, with 29% of commercial fish stocks now classed as overexploited, and 61% classed as fully exploited.

And the damage isn’t limited to fish - the report found that total marine populations have been cut in half since 1970, with turtles, sharks, sea birds and marine mammals all facing dangerous decline.

Thankfully, it isn’t all bad news. “Recent assessments from the North Sea have shown that just over 50% of assessed stocks, including herring and haddock, are being fished sustainably,” said Professor Ken Norris, ZSL director of science.

Progress is being made in the designation of Marine Protected Areas, but the UK Government must do more to ensure their delivery, he added.

Shoppers and retailers can also help stop the decline by ensuring the fish they eat and source is sustainable, said Dr Louise Heaps, chief advisor on Marine Policy at WWF-UK. “Every one of us can take meaningful action, starting today, by ensuring that all the seafood we eat is responsibly sourced and Marine Stewardship Council-accredited,” she said.