Wild caught tuna is tuna that was harvested from its natural ocean habitat rather than raised in a farm or pen. Virtually all canned tuna on store shelves is wild caught, since tuna farming remains limited and mostly supplies the fresh sushi market. The label tells you something specific about how the fish was sourced, but it doesn’t tell you everything about how it was caught or whether the fishery is sustainable.
What the Label Legally Means
U.S. federal regulations require retailers to disclose both the country of origin and the method of production for seafood. The accepted terms are “wild caught” or “wild” for fish harvested from open water, and “farm-raised” or “farmed” for aquaculture products. Phrases like “ocean caught,” “caught at sea,” or “line caught” are not legally acceptable substitutes, even though they sound similar. The label must be displayed conspicuously at the point of sale, whether as a placard, sticker, sign, or printed on the package itself.
For canned tuna specifically, you’ll almost always see “wild caught” because the canned tuna industry depends on capture-based fisheries for its raw material. Tuna farming operations that do exist primarily fatten wild-caught juvenile fish in ocean pens and sell them fresh, often to high-end sushi markets. These operations still rely on wild fish meal and oil for feed, which raises its own set of environmental questions.
How Wild Tuna Is Actually Caught
The term “wild caught” covers a wide range of fishing methods, and the differences between them matter more than the label itself suggests.
Pole-and-line fishing uses individual baited hooks operated by hand. Trolling lines drag baited hooks behind a moving boat. These selective methods catch tuna one at a time, which dramatically reduces the number of other marine species accidentally caught (known as bycatch). On canned tuna labels, you’ll see these described as “pole-caught,” “pole-and-line,” or “troll-caught.”
Drifting longlines are a different story. A single longline can stretch up to 50 miles with thousands of baited hooks spaced along branch lines. While effective at catching tuna, longlines also hook sea turtles, sharks, and seabirds at much higher rates. When a can says “line-caught,” it usually means longline, not the more selective pole-and-line method.
Purse seine nets are large nets that encircle entire schools of fish. Some purse seine operations use fish aggregating devices (FADs), floating objects that attract tuna and many other species. FAD-free purse seining, sometimes labeled “free school” or “school-caught,” targets naturally forming schools and tends to have lower bycatch.
What “Dolphin Safe” Does and Doesn’t Mean
Many wild caught tuna cans also carry a “dolphin safe” label, but it’s worth understanding what this actually certifies. Under U.S. law, the captain of the fishing vessel must provide a written statement certifying that no nets or gear were intentionally deployed on or used to encircle dolphins during the trip, and that no dolphins were killed or seriously injured during the catch. Since May 2016, captains must also complete a Dolphin-Safe Captain’s Training Course.
What the dolphin-safe label does not address is broader environmental sustainability. A fishery can be dolphin-safe while still generating significant bycatch of sharks, rays, sea turtles, or juvenile fish. As Seafood Watch notes directly: dolphin-safe does not mean the tuna is environmentally sustainable.
Sustainability Labels Worth Knowing
If environmental impact matters to you, look beyond “wild caught” to more specific certifications. The Marine Stewardship Council (MSC) blue label indicates that an independent auditor evaluated the fishery across three principles: that enough fish remain in the sea for the population to reproduce indefinitely, that fishing operations maintain the diversity and health of the marine ecosystem, and that the fishery has effective management systems that comply with relevant laws. Fisheries are scored on 28 separate indicators across these three areas.
For canned and pouched tuna specifically, Seafood Watch recommends looking for Atlantic or Pacific tuna labeled with one of these terms: pole-caught, pole-and-line, troll-caught, or FAD-free. These designations tell you far more about the environmental footprint of your tuna than “wild caught” alone.
Nutrition: Mercury and Omega-3s
All wild tuna contains omega-3 fatty acids, the type linked to heart and brain health. The amount varies significantly by species. Bluefin tuna delivers the most, with roughly 1.6 grams of EPA and DHA (the two omega-3s your body uses most readily) per 100-gram serving. Albacore provides about 1.3 grams per 100 grams. Lighter tuna species, like skipjack, contain closer to 0.5 grams per serving.
Mercury is the main safety consideration with any tuna, and it’s a tradeoff with the omega-3 benefits. According to FDA monitoring data, skipjack tuna has the lowest average mercury concentration at 0.144 parts per million. Yellowfin comes in at 0.354 ppm, and albacore at 0.358 ppm (0.350 ppm for canned albacore specifically). In practical terms, this means “light” canned tuna, which is typically skipjack, contains roughly two and a half times less mercury than “white” canned tuna, which is albacore. People who eat tuna frequently, especially pregnant women and young children, benefit from choosing skipjack more often.
What to Look for at the Store
When you pick up a can or pouch of tuna labeled “wild caught,” you’re getting a fish that lived and fed in the open ocean. That’s genuinely different from farmed salmon or tilapia, which spend their lives in pens eating manufactured feed. But among wild caught tuna products, the variation in fishing methods, species, and environmental impact is enormous.
The most useful information on a tuna label isn’t “wild caught” itself. It’s the species (skipjack vs. albacore), the catch method (pole-and-line vs. longline), and any third-party certification like MSC. A can that says “wild caught, pole-and-line, skipjack” is telling you something very specific: a lower-mercury fish caught with minimal bycatch. A can that says only “wild caught tuna” is giving you the bare legal minimum.