Atlantic Bluefin Tuna Diet in the UK: Exploring the Feast of Thunnus thynnus in 2025
Atlantic Bluefin Tuna Diet in the UK
Atlantic Bluefin Tuna Diet in the UK: Exploring the Feast of Thunnus thynnus in 2025
What’s on the Menu for Atlantic Bluefin Tuna in the UK? (#whats-on-the-menu-for-atlantic-bluefin-tuna-in-the-uk)
The Atlantic bluefin tuna (Thunnus thynnus), a majestic predator of UK waters, has a diet as dynamic as its powerful swimming. These giants, which have made a remarkable return to British seas, are opportunistic feeders with a broad palate. Research on their feeding habits, primarily from the Mediterranean, offers insight into their preferences. In the central Mediterranean Sea, studies have identified 91 prey taxa in bluefin stomachs, with mesopelagic and benthopelagic fish like the myctophid Hygophum benoiti (22.85% IRI) and the stomiid Chauliodus sloani (15.12% IRI) dominating, alongside squids like Illex coindetii (14.32% IRI). When grouped, mesopelagic and benthopelagic fish make up 54.41% of their diet by relative abundance, showing a preference for high-energy prey during pre-spawning and spawning seasons.
In UK waters, particularly off Cornwall and Pembrokeshire where bluefin are now regularly spotted, their diet likely mirrors this generalist behavior. They’re known to target small schooling fish such as mackerel, sprats, and herring—species abundant in British waters during their season from mid-August to mid-December [Web ID: 10]. Bluefin also feed on cephalopods like squid, which are prevalent in the Celtic Deep off Pembrokeshire. Their feeding rhythm suggests they hunt diel-migrating fauna at night and larger prey during the day, capitalizing on the rich marine ecosystems of the UK.
Do Bluefin Tuna in South Devon Eat Garfish? (#do-bluefin-tuna-in-south-devon-eat-garfish)
While garfish aren’t explicitly listed in studies of Atlantic bluefin tuna diets, it’s plausible they could be on the menu in South Devon. Garfish, slender and swift, are abundant in these waters and share the same coastal habitats as bluefin prey like mackerel and sandeels. Bluefin are generalist predators, and their diet includes fish from families like Exocoetidae and Hemiramphidae, which are related to garfish. Given their opportunistic nature, a bluefin encountering a garfish in South Devon’s inshore waters—say, around Paignton or Brixham—might not hesitate to strike. However, without direct evidence, this remains speculative. More local studies are needed to confirm if garfish are a regular part of their diet in this region.
Why Their Diet Matters for Sustainability (#why-their-diet-matters-for-sustainability)
Understanding the diet of Atlantic bluefin tuna is key to sustainable management in UK waters. The species, once endangered, is now classified as “near threatened” by the IUCN, thanks to improved international management. Their return to British waters, with a 2024 UK quota of 66.15 tonnes for recreational, commercial, and tagging programs, highlights the need for balance. Programs like the Catch and Release Recreational Fishery (CRRF) in Devon and Cornwall, alongside initiatives like CHART Cymru and Thunnus UK, track bluefin movements and diets to ensure their prey populations—like mackerel and herring—aren’t overexploited
Bluefin feeding on a variety of prey, potentially including garfish in South Devon, underscores the importance of maintaining healthy ecosystems. Overfishing their prey could disrupt their recovery, while sustainable fishing practices—like those in the 2024 CRRF—support both the tuna and the broader marine food web. As anglers chase record-breaking catches in 2025, like those seen in the Atlantic Bluefin Tuna Championship, we must prioritize the health of their prey to keep these giants thriving
