Hokkaido's rich marine ecosystems

Hokkaido has two coastal national parks with diverse marine environments that support a wide range of aquatic life. The seas have sustained local communities for generations through fishing, and gathering kelp. 

At Hokkaido’s northern tip is Rishiri-Rebun-Sarobetsu National Park. It comprises three areas: the vast peat marshlands of the coastal Sarobetsu Plain; Rebun Island (Japan’s most northerly island), with scenic hiking trails and rich fishing grounds; and Rishiri Island, an almost perfectly circular volcanic island surrounded by dense kelp forests. The cold Liman Current from Russia and the warm Tsushima Current from southern Japan meet in the waters of this national park, creating marine environments with different temperature, salinity, and nutrient profiles. This results in a rich environment for aquatic life.

The coastal waters of Rishiri-Rebun-Sarobetsu National Park support life in the northern reaches of Hokkaido and supply tables throughout Japan with rich, creamy sea urchin, plump abalone, and other delicacies fostered by vast kelp forests and intersecting ocean currents.

On the eastern side of Hokkaido, the Shiretoko Peninsula juts out into the Sea of Okhotsk. It is separated from the most southerly of the Kuril Islands by the Nemuro Strait, with waters ranging in depth from around 20 to 2,000 meters. Shiretoko National Park covers a large section of the peninsula, and the surrounding waters are some of Japan’s richest fishing grounds. Two hundred and twenty-three species of fish have been collected from the peninsula’s coastal waters, including 10 species of salmonid. The rich biodiversity of these waters is attributed to converging ocean currents, and seasonal sea ice, which supports the formation of phytoplankton. Shiretoko is designated a World Natural Heritage site for the diversity of its marine and terrestrial ecosystems.

Kombu (kelp)

Kelp (or kombu) plays an essential role in Japanese cuisine and contributes significantly to Hokkaido’s reputation for abundant, high-quality seafood. It is one of the main ingredients in dashi—an umami-rich stock that is essential to many Japanese dishes. Kombu can be eaten in many ways—pickled, in salads, in soups and hotpots, or folded into onigiri (rice balls). It is a versatile ingredient enjoyed raw, dried, or simmered.

Kombu is rich in dietary fiber and amino acids as well as minerals like calcium, iron, and iodine. Iodine is an important nutrient for sea creatures such as sea urchin and abalone, and the type of kombu they feed on influences their unique flavor profile. Many varieties of kombu are harvested in the coastal waters of Hokkaido’s national parks. 

Rausu kombu is harvested along the Shiretoko Coast, within the boundaries of Shiretoko National Park. This reddish-brown variety of kelp is used for both dashi and traditional Japanese dishes such as tsukudani—kombu with seafood or meat simmered in soy sauce.

Rishiri kombu is gathered along the coast of northern Hokkaido, from Haboro to Abashiri and throughout Rishiri-Rebun-Sarobetsu National Park including on the islands of Rishiri and Rebun. This variety has a firm, chewy texture and makes for a flavorful dashi.

For centuries, kombu has been harvested, air-dried and transported throughout Japan—creating a unique food culture.

Uni (sea urchin)

Hokkaido has a reputation for some of the richest and most flavorful uni in Japan. Sea urchins from the region are popular for their deep, golden hued innards that pack a distinct, briny-umami flavor and buttery sweetness. This delicacy can be enjoyed fresh, or grilled in its shell.

There are different types of uni in Rishiri-Rebun-Sarobetsu and Shiretoko national parks, such as the short-spined Ezo Bafun (also called Ganze) and the long-spined Kitamurasaki (or Nona). The catch season runs throughout the year, depending on the location and variety. Uni around the islands of Rishiri and Rebun are harvested from January to May. On Hokkaido’s eastern coast, within the boundaries of Shiretoko National Park, they are harvested from late October to late April. Local fishermen catch uni by hand from small boats, using a rod with a net on the end. Uni are a favorite of sea otters whose appetites can affect the annual catch.

Abalone

Abalone is a large, oval mollusk with subtle differences in flavor depending on its food source. Ezo abalone is a variety found along the coast of Rishi-Rebun-Sarobetsu National Park which feeds on Rishiri kombu. This type is a little smaller than abalone found elsewhere in Japan and has firm yet tender flesh and a rich flavor. 

The punchy saltiness of abalone is balanced by its creamy sweetness. It can be eaten raw, lightly grilled, boiled or steamed. The innards are sometimes served pickled. Abalone is caught throughout the year depending on the variety and location. The season for Ezo abalone is typically from October to December. 

Abalone adhere to rocks with powerful suction. This makes the harvesting process laborious, as divers have to remove them individually by hand or with a special type of hand-net attached with a scraper. The seas are usually cold and rough during Ezo abalone harvesting season, so fishing is often only possible for a few days. Abalone is often served at high-end ryokan inns and as part of multicourse kaiseki meals.

Shrimp

The botanical-plankton rich waters of the Nemuro Strait in Shiretoko National Park are a rich source of nutrients for marine life such as kombu and shrimp. Colonies of kelp are a protective home for many varieties of shrimp including the striped Hokkai shrimp, grape shrimp, and botan shrimp. 

Each variety has its own distinct flavor profile, and is prepared differently. Hokkai shrimp become especially sweet and turn a vibrant red when they’re boiled. Grape shrimp are delicate and sweet, and are often served raw as sashimi. Botan shrimp are more robust and can be enjoyed in a variety of ways, from sushi to shabu-shabu.

Hokkaido’s shrimp are caught in different seasons throughout the year. Hokkai shrimp are a rare delicacy, and only fished in very small numbers in early summer and mid-fall to sustain the population. Even rarer are grape shrimp, named for their delicate purple hue when raw. Due to previous overfishing, conservation regulations permit only a few kilos to be landed each day during the short season from August to September. Their pleasant texture and subtly sweet flavor makes them a sought-after ingredient at top sushi restaurants.

Salmon

Salmon in Hokkaido feed on nutrient-rich zooplankton and shrimp in the Nemuro Strait. The rich, creamy flesh from the fish is used in dishes such as Nemuro Strait salmon chazuke—a dish made by pouring green tea, dashi, or hot water over cooked rice and Nemuro Strait salmon. 

Salmon roe (eggs) is another popular and nutritious ingredient. These red-orange orbs burst with savory umami, and are generously used in the Hokkaido specialty, tsukko meshi—salmon roe brined in soy sauce over rice.  

If you’re in Shiretoko in the fall, look out for sushi and sashimi made with keiji (young, fatty chum salmon), a rare autumnal delicacy. Chan chan yaki—grilled salmon and vegetables cooked with miso and served on rice—is a local staple commonly served in fishing towns around Hokkaido. 

To try some of these traditional dishes, you can restaurant-hop in the fishing towns of Shiretoko National Park. There are also chum salmon fishing tours along the Sea of Okhotsk where you can take fresh catches home to cook yourself.

Hokkaido's fish markets

Fresh seafood caught in Hokkaido’s bountiful oceans is shipped and sold at fish markets throughout Japan, and air-freighted around the world. Head to markets in national parks or local towns to try Hokkaido’s delicious seafood including sea urchin, crab, and fatty tuna. 

While exploring the national parks, you can visit the market next to Shiretoko World Heritage Conservation Center in Utoro. Elsewhere in Hokkaido, you can visit the Triangle Market in the east-coast city of Otaru, the wholesale market in Obihiro’s Fujimaru department store, or Nijo Fish Market in Hokkaido’s capital city of Sapporo.