National Parks · Hokkaido

Kushiro-shitsugen National Park

釧路湿原国立公園くしろしつげんこくりつこうえんKushiro-shitsugen Kokuritsu Kōen

Japan's great marsh and home of the red-crowned crane

Kushiro-shitsugen National Park protects Japan's largest wetland, a vast marsh of reeds, sedges and alder on the Kushiro River plain just north of the city of Kushiro in eastern Hokkaido. Japan's first Ramsar site in 1980 and a national park since 1987, it is the heartland of the red-crowned crane.

Area: 287.88 km²National park · 1987Ramsar wetland · 1980

Overview

The Kushiro Marsh spreads over the lower plain of the Kushiro River immediately north of the port city of Kushiro. It is Japan's largest wetland: a flat, almost treeless expanse of reed beds, sedge meadows and alder thickets crossed by slow, looping rivers and dotted with small lakes. The national park, designated in 1987, covers the marsh and its surrounding hills.

The marsh is the stronghold of the red-crowned crane, a bird that had almost vanished from Japan by the early 20th century and survived here in a small remnant population. Protection, winter feeding and habitat conservation have allowed it to recover, and the crane has become a symbol of Hokkaido.

Because the marsh sits directly beside a regional city and farmland, its protection has been a model for wetland conservation in Japan. Straightened river channels, drainage and sediment from farmland shrank the marsh in the 20th century; since the early 2000s restoration projects have re-meandered sections of river and restored wet ground.

Landscape and formation

The Kushiro plain was a shallow bay during the warm Jōmon transgression around 6,000 years ago. As sea level fell and a sand bar closed the bay, it became a lagoon and then filled with river sediment and peat, a process still visible in the layers of the marsh. Low, rounded hills of older terrace deposits surround the plain, providing the observation points.

The Kushiro River rises in Lake Kussharo and winds through the marsh in wide meanders, joined by the Kuchoro, Setsuri and other rivers. On the east side lie the lakes Tōro-ko, Shirarutoro-ko and Takkobu-numa, remnants of the old lagoon. The types of wetland vary from low reed and sedge fen, fed by river water, to Sphagnum raised bog at the Akanuma area, fed only by rain.

Highlights

Hosooka Observatory
細岡展望台Hosooka Tenbōdai
A viewpoint on the eastern hills over the meandering Kushiro River, with the Akan volcanoes on the horizon; known for sunsets.
Kushiro City Wetland Observatory
釧路市湿原展望台Kushiro-shi Shitsugen Tenbōdai
Observation building and boardwalk loop on the western edge of the marsh, close to Kushiro city.
Onnenai boardwalk
温根内木道Onnenai mokudō
A level boardwalk through reed fen and alder woodland from the Onnenai Visitor Center, the best walk into the marsh itself.
Lake Tōro
塔路湖Tōro-ko
The largest lake in the marsh, next to Tōro station, starting point for canoe trips on the Kushiro River.
Kushiro River
釧路川Kushiro-gawa
The meandering river through the marsh, one of Japan's best-known canoeing rivers.
Kottaro Wetland Observatory
コッタロ湿原展望台Kottaro Shitsugen Tenbōdai
A remote hilltop lookout over the undeveloped north-western part of the marsh, part of the special protection zone.

Ecology

The marsh supports over 600 plant species and a rich wetland fauna, including many northern species at the southern edge of their range. Reeds and sedges dominate the fens, Japanese alder forms open woodland along the rivers and on drier ground, and Sphagnum bog with cranberries and Labrador tea occupies the rain-fed centre.

Apart from the crane, the marsh is known for relict species from colder periods: the Siberian salamander, found in Japan almost only here, the Sakhalin taimen, Japan's largest freshwater fish, and the dragonfly Leucorrhinia intermedia ijimai. Sika deer, whose numbers have grown, are an increasing pressure on the vegetation.

Flora

Reed and sedge fen
ヨシ・スゲyoshi, suge
The dominant plant cover of the marsh, turning green in June and golden in autumn.
Japanese alder
ハンノキhannoki
The only tree common in the marsh, forming open woodland; its spread is a sign of drying ground.
Kushiro Jacob's ladder
クシロハナシノブKushiro-hanashinobu
A rare blue-flowered wetland plant named after the Kushiro region.
Labrador tea and Sphagnum bog
イソツツジ・ミズゴケiso-tsutsuji, mizugoke
Raised-bog vegetation in the Akanuma area, fed only by rainwater.

Fauna

Red-crowned crane
タンチョウtanchō
A Special Natural Monument; the marsh is its main breeding ground in Japan, and the resident population has recovered from barely a few dozen birds.
Siberian salamander
キタサンショウウオkita-sanshōuo
A cold-adapted salamander that survives freezing; in Japan found almost exclusively in the Kushiro Marsh.
Sakhalin taimen
イトウitō
Japan's largest freshwater fish, an endangered salmonid of slow northern rivers.
Ezo-kaojiro dragonfly
エゾカオジロトンボEzo-kaojiro-tonbo
A white-faced darter of northern bogs, living in the marsh's pools.
White-tailed eagle
オジロワシojirowashi
Breeds and winters around the marsh and its rivers.

Culture

Shell mounds and pit-dwelling sites on the hills around the marsh, including the Higashi-Kushiro shell mound, show that people lived on the shores of the former bay in the Jōmon period. The Ainu later used the rivers as routes inland and for salmon fishing; many names, including Kushiro, Tōro and Kottaro, are of Ainu origin.

In modern times the marsh was long regarded as wasteland to be drained. Its reassessment as a natural treasure began with the protection of the crane and culminated in the Ramsar listing of 1980, the national-park designation of 1987 and the Ramsar conference held in Kushiro in 1993.

Onnenai Visitor Center
温根内ビジターセンターOnnenai Bijitā Sentā
Visitor centre at the start of the Onnenai boardwalk with exhibits on wetland ecology.
Kushiro Japanese Crane Reserve
釧路市丹頂鶴自然公園Kushiro-shi Tanchōzuru Shizen Kōen
A crane breeding and conservation facility on the edge of Kushiro city where cranes can be seen all year.
Kushiro Marsh sightseeing trains
Seasonal slow trains on the JR Senmō Line along the eastern edge of the marsh.

History

c. 6,000 years ago
At the height of the Jōmon transgression the sea fills the Kushiro plain as a shallow bay.
c. 3,000 years ago
The former bay has become a lagoon filling with peat, forming the marsh.
1924
A small group of red-crowned cranes is rediscovered in the marsh after the species was feared extinct in Japan.
1952
The red-crowned crane is designated a Special Natural Monument.
1980
The marsh becomes Japan's first Ramsar wetland.
1987
Kushiro-shitsugen National Park is designated on 31 July.
1993
Kushiro hosts the fifth Conference of the Parties to the Ramsar Convention.
2000s
Nature restoration projects begin, including returning straightened river sections to their meanders.

Through the seasons

Spring

Snow melts in April; skunk cabbage flowers in the alder woods and cranes lay eggs hidden in the reeds.

Summer

The marsh turns green; morning fog from the Pacific is frequent. The main season for canoeing and the sightseeing trains.

Autumn

Reeds turn golden-brown in September and October, with clear skies and good views of the Akan volcanoes.

Winter

Cold and dry with little snow. Cranes gather at feeding sites around the marsh, and steam fog rises from the unfrozen rivers on the coldest mornings.

Routes and trails

Onnenai boardwalk
A loop of about 3 km through fen and alder woodland, mostly level.
Kushiro City Wetland Observatory trail
A boardwalk loop of about 2.5 km from the observatory to a satellite lookout.
Hosooka and Tōro area walks
Short paths from Kushiro-shitsugen and Tōro stations to viewpoints over the river.
Kushiro River canoe
Guided or independent canoe trips from Tōro-ko or further upstream through the heart of the marsh.

Practical notes

Kushiro airport and Kushiro station are the gateways; JR Kushiro-shitsugen and Tōro stations on the Senmō Line give direct access to the east side.
Most of the marsh is off limits; stay on boardwalks and paths, which also protects the peat.
Keep well away from cranes, especially nesting pairs in spring and summer; use long lenses rather than approaching.
Mosquitoes and ticks are common in summer; wear long sleeves in the woods.

Frequently asked questions

Where can red-crowned cranes be seen?

In summer the cranes nest hidden in the marsh and are hard to see. In winter they gather at feeding grounds around the marsh, notably in Tsurui village and at the Akan International Crane Center, where they dance in the snow.

What is the best way to see the marsh?

From the observation decks at Hosooka and the Kushiro City Wetland Observatory, on the boardwalks at Onnenai, by canoe on the Kushiro River, or from the seasonal sightseeing trains on the JR Senmō Line.

Why is Kushiro-shitsugen important internationally?

It was designated Japan's first wetland under the Ramsar Convention in 1980, and Kushiro hosted the fifth Ramsar Conference of the Parties in 1993.

How was the marsh formed?

About 6,000 years ago the sea reached far inland here during a warm period. As it retreated, the bay became a lagoon and gradually filled with sediment and peat, leaving the flat, wet plain seen today.

Sources

1.釧路湿原国立公園 (opens in a new tab) — 環境省
2.国立公園の概要 (opens in a new tab) — 環境省
3.Kushiro-shitsugen National Park (opens in a new tab) — Ministry of the Environment, Japan
4.Ramsar Sites Information Service (opens in a new tab) — Ramsar Convention Secretariat