Raw Fish Around the World
Traditions, Safety, and What to Try

The Universal Question: Parasites

Before touring the traditions, the underlying biology matters. Most raw fish risk comes from two parasite families: Anisakis nematodes (found in marine fish — cod, herring, mackerel, wild salmon, tuna) and liver flukes (Clonorchis sinensis, Opisthorchis viverrini) found only in freshwater fish. The two groups require completely different risk management.

Anisakis is killed reliably by freezing to −20°C for at least 7 days, or to −35°C for 15 hours. Farm-raised fish fed formulated pellets (with no ocean-access prey) show 0% Anisakis prevalence in large-scale surveys — the parasite's lifecycle requires sea mammals as definitive hosts, which pellet-fed fish never encounter. Liver flukes in freshwater fish cannot be killed by acid, spice, or short-term freezing; only thorough cooking or heavy, long-duration fermentation with concentrated salt destroys the infective metacercariae.

This distinction — marine versus freshwater, freezable versus not — explains why some raw fish traditions are easily replicated safely at home, while others remain genuinely high-risk regardless of preparation technique.

Japan: Sashimi and Sushi

The Japanese tradition is the most technically sophisticated and the one most focused on the quality of the raw ingredient itself. Sashimi — thinly sliced raw fish eaten with soy sauce and wasabi — was named in the Muromachi period (1336–1573), when aristocrats and samurai began eating unfermented raw seafood sliced thin. The word itself is old: the earliest dipping condiment was salt or vinegar, later mustard, and only later the soy-wasabi combination now universal.

The deeper history connects Japan to Southeast Asia. The earliest ancestor of sushi was narezushi — freshwater fish fermented with rice and salt, the rice discarded after fermentation. It originated in the Mekong River basin and spread to Japan during the Yayoi period. Over centuries, fermentation time shortened: namanare in the Muromachi period was partially fermented; haya-zushi in the Edo period (1603–1867) replaced fermentation entirely with vinegar-seasoned rice, turning sushi into fast food. Hanaya Yohei refined the hand-pressed nigiri form in Edo (now Tokyo) around 1824 — the style that spread globally.

One revealing fact: Japan did not eat raw salmon until the late 1980s. The risk of Anisakis in wild Pacific salmon was too high, and Japanese fish culture recognized it. The shift came when Norwegian fish companies, with a surplus of farmed salmon, negotiated a deal with Japanese importer Nichirei. Farmed salmon — raised on pellets with no sea-mammal prey in their environment — carries zero Anisakis. Japan tested, confirmed, and adopted it. Today salmon sashimi is one of the most popular items at sushi counters worldwide, entirely because of that single supply chain decision.

Korea: Hoe

Korean raw fish — hoe (회) — shares surface similarities with Japanese sashimi but diverges in almost every detail. Where Japanese sashimi keeps condiments minimal to let the fish speak, Korean hoe is meant to be bold: the fish is dipped in cho-gochujang (chili paste with vinegar) or ssamjang (chili and soybean paste), wrapped in lettuce or perilla leaves, and eaten as a wrap. The sauces are robust enough to stand against strong-flavored species.

The tradition has deep roots. Chinese raw fish and meat dishes (kuai, º) were considered delicacies in ancient China — described in the Analects of Confucius in detail, from slice thickness to seasonal sauces. Korea adopted the practice during the Three Kingdoms period. After a decline during the Buddhist era (which discouraged killing), hoe resurged strongly in the Joseon dynasty, fueled partly by the Confucian association with Confucius himself having enjoyed raw foods.

The Korean tradition distinguishes between two preparation styles: hwareo-hoe, made from freshly killed fish (extreme freshness as the safety strategy), and seoneo-hoe, which ages the fish at controlled temperature before slicing — closer in approach to Japanese sashimi. Common species include flounder (gwangeo, the most popular), amberjack, mackerel, and squid. After the fish is eaten, the remaining bones and head are often made into a spicy stew (maeun-tang).

Peru and Latin America: Ceviche

Ceviche's origins go back over 2,000 years to the coastal Moche civilization of northern Peru, where raw fish was marinated in the fermented juice of banana passionfruit (tumbo) and mixed with chili and salt. The Inca used chicha (fermented corn beer) as the marinade. The modern form — citrus-cured seafood with onions, chili, and cilantro — arrived in the 16th century when Spanish colonizers introduced limes and lemons, combined by indigenous cooks with the existing raw-fish tradition. UNESCO recognized ceviche as an Intangible Cultural Heritage of Peru in 2023.

The chemistry is frequently misunderstood. Citric acid from lime juice lowers pH and denatures the fish proteins: the flesh turns firm and opaque, appearing cooked. But protein denaturation is not the same as pathogen elimination. Acid marination does not kill Anisakis parasites and provides only incomplete protection against bacteria. A 2001 study in the Journal of Food Protection found that lime juice effectively reduced Vibrio parahaemolyticus but showed incomplete inactivation against Salmonella enterica. Traditional Peruvian ceviche was marinated for hours; modern ceviche (developed in the 1970s partly by Peruvian-Japanese chefs influenced by sashimi technique) marinates for minutes — the acid serves primarily as a flavor agent, not a safety step.

Safety in Peruvian ceviche traditionally rests on three things: extreme freshness (consuming immediately after preparation), use of local white-fleshed marine species (corvina, lenguado, mero) that tend to carry lower Anisakis loads than fatty pelagic fish, and the cold coastal waters of the Pacific, which limit bacterial proliferation. The regional variety is significant: Ecuador uses tomato-based tiger's milk; Mexico uses fiery aguachile; Bolivia and Chile adapt to local geography and available species.

Scandinavia: Gravlax

The word gravlax means “buried salmon” in Swedish (from grav, grave, and lax, salmon). The name is literal. In remote Nordic areas where fish were caught in massive quantities over a short season and salt was scarce and expensive, the solution was to bury cleaned, lightly salted fish in holes dug into the earth alongside carbohydrates (pine bark, whey, malted barley) and antioxidants (pine needles, berries). This created conditions for lacto-fermentation: lactic acid bacteria from the fish and the local environment outcompeted harmful pathogens, dropping pH and preserving the fish through acid rather than salt alone.

The parallel with Japanese narezushi is striking. Both traditions arose independently from the same underlying logic: use fermentation to preserve fish safely when refrigeration is unavailable. Both involved fish plus carbohydrate (rice in Japan; grain or bark in Scandinavia) and both produced an acidic, preserved product with an acquired taste that modern versions have moved away from. Nordic Food Lab research has traced the etymology and historical record — gravlax is part of a family of Scandinavian fermented fish that includes Swedish surlax (sour salmon) and Norwegian rakfisk (soaked fish), some still made by traditional methods.

Modern gravlax has abandoned fermentation entirely. It is now a cure — salt, sugar, and dill applied directly to the fish for 24–72 hours in the refrigerator. The safety model has changed accordingly: modern gravlax relies on parasite-free farmed salmon (Anisakis prevalence in farmed Atlantic salmon in Norway: 0% across thousands of samples) and cold-chain management rather than lactic acid fermentation. The result is a product that is structurally raw — not cooked, not fermented — but safe under the current supply chain model.

The Arctic: Inuit Fermented Fish

In the extreme Arctic where agriculture is impossible, the Inuit subsisted almost entirely on animal foods — often eaten raw, dried, or fermented. Traditional fermented Inuit foods include marine mammals (walrus, whale, seal, narwhal) and fish (Arctic char, trout). The fermented fish tradition, sometimes called stinkheads (fermented salmon heads) in Alaska, is one of the few raw fish traditions where the fermentation proceeds with no added salt, no starter culture, and no direct temperature control — entirely unlike the salt-heavy Asian fermented fish traditions or the cold-earth burial of Scandinavian gravlax.

Safety in traditional Inuit fermentation relied on two factors: temperature (the cool Arctic earth maintained consistently cold conditions) and the traditional knowledge passed down about safe preparation. The latter has degraded significantly as traditional practices have declined. The main modern food safety risk is botulism: when traditional porous containers (wooden barrels, seal-skin pouches) were replaced by modern plastic buckets in the mid-20th century, the tightly sealed anaerobic environment encouraged Clostridium botulinum growth, especially if the containers were left exposed to warmer temperatures. Botulism rates in northern Alaska are unusually high compared to other parts of the world, primarily from improperly prepared traditional fermented foods.

Only 15% of students in surveyed Inuit communities consume traditional fermented foods today, compared to 80% of grandparents — the knowledge gap creates safety risk for those who do continue the tradition without full understanding of the temperature and container requirements.

Southeast Asia: Koi Pla and the Freshwater Fish Problem

Southeast Asia presents the most complicated picture in global raw fish consumption. The region is, historically, the origin of the sushi tradition — narezushi's ancestor developed in the Mekong River basin. And yet raw freshwater fish consumption in the region carries the highest documented public health burden of any raw fish tradition worldwide.

Koi pla is freshly chopped raw freshwater fish mixed with lime juice, herbs, and spicy ingredients — served immediately. The lime juice denatures the proteins (the same mechanism as ceviche) but does not kill the parasite that makes this dish dangerous: Opisthorchis viverrini, a liver fluke. After infection, the parasite survives in the bile duct and causes chronic inflammation. The International Agency for Research on Cancer (IARC) has classified O. viverrini as a Group 1 human carcinogen — directly linked to cholangiocarcinoma (bile duct cancer). Thailand has the highest cholangiocarcinoma incidence in the world, with rates estimated at 93.8–317.6 per 100,000 person-years in endemic areas. An estimated 9 million people in the Mekong basin are infected.

The contrast with pla ra — the other major uncooked fish preparation in the same communities — is instructive. Pla ra is freshwater fish fermented in a highly concentrated salt solution for 3–6 months. The extreme salinity destroys the infective metacercariae. The same fish, the same parasite, the same communities — but one preparation method is dangerous and the other is safe. Health campaigns in Thailand now focus on this distinction: koi pla carries risk; pla ra does not.

An additional risk emerged in 2015: an outbreak in Singapore linked to raw freshwater fish identified a foodborne strain of Group B Streptococcus (GBS, sequence type ST283). GBS had not previously been recognized as a foodborne pathogen in healthy adults. FAO has issued risk profiles noting that freezing is not an effective control measure for GBS — only cooking eliminates the risk. The outbreak affected healthy adults, not just immunocompromised individuals.

Hawaii and the Pacific: Poke

Hawaiian poke (ʻahi poke, made from raw yellowfin tuna) occupies an interesting position: it is a Pacific Islander tradition that encountered Japanese influence in Hawaii and produced a distinct hybrid form. Traditional poke involved raw fish cut in chunks and mixed with sea salt, seaweed (limu), and crushed kukui nut. After the Japanese community's influence in Hawaii, soy sauce, sesame oil, and green onion became standard additions. The late-20th century poke bowl format is a further commercial evolution — the fish is now sold in grocery stores and bowl restaurants across the mainland US.

Safety for poke follows the same marine fish guidelines: wild tuna should be commercially frozen before raw consumption. The FDA requires this for raw fish served to the public at food service establishments. Species matters: yellowfin tuna (ʻahi) carries relatively low Anisakis prevalence compared to, say, cod or herring, because tuna are pelagic and their feeding habits result in lower parasite loads — but the risk is not zero.

Safety Summary: What Actually Works

Sources

• Sushi — Wikipedia / Yamaguchi University research. Historical sushi timeline from narezushi to Hanaya Yohei nigiri (1824). Raw salmon introduction via Norwegian farmed fish deal with Nichirei (late 1980s).
• Hoe (Korean raw fish) — Wikipedia article on hoe; Hankyoreh historical record; Korean food safety data on Anisakis, Kudoa, Clonorchis sinensis, Vibrio. Korea hoe tradition from Three Kingdoms period through Joseon revival.
• Ceviche — Wikipedia article on ceviche; Gastronomica Vol. 22 No. 4 (2022); J. Food Prot. 64(10):1577–80 (2001, Terrazas et al., lime juice vs. Salmonella and Vibrio); UNESCO ICH listing (Peru, 2023); FAO Fisheries Technical Paper No. 444 (2003).
• Gravlax — Nordic Food Lab. "Gravlax – a buried salmon" (July 2025, Guillemette Barthouil). Historical etymology (Falk and Torp, 1906); fermentation parallels with narezushi (Mouritsen 2009, Hariono 2005). Anisakis prevalence in farmed vs. wild salmon: FAO table (ICMSF 2003); Deardoff and Overstreet (1991).
• Inuit fermented fish — J. Ethnic Foods 2024 (Campbell et al.). Botulism risk from plastic containers; traditional porous container safety logic; microbiome data.
• Koi pla / Southeast Asia — PLOS ONE study, Chachoengsao Province, Thailand (2012–14); FAO GBS risk profile (FAO Asia-Pacific, 2015 Singapore outbreak); Opisthorchis viverrini IARC Group 1 classification; cholangiocarcinoma incidence data.
• FAO Seafood Safety & Quality Framework; WHO Food Safety guidelines on raw fish.