Four Seasons in Japan: Drift ice attached to coasts of Hokkaido

White lines of drift ice had been spotted off the coast of Wakkanai on January 25, according to the Wakkanai Local Meteorological Observatory. The ice came 19 days earlier than usual. Abashiri Local Meteorological Observatory reported this year's first drift ice came into view off the Abashiri coast On January 31 ten days later than usual and the ice became attached to the land on February 2.

Cape Notoro surrounded by sea ice, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

Monbetu City announced that the ice became attached to the land on February 3.

icebreaker Garinko II at Monbetsu Port
photo by 動物写真集（アザラシ・シロクマ・旭山動物園）

Each year, the Wakkanai, Kushiro and Abashiri local meteorological observatories announce the first day that this ice can be seen with the naked eye from the coast, the last day that the ice could be seen, the day that sea routes became unnavigable due to the ice attached to the land along coastlines and the day that sea routes became navigable.

Fast ice along the Shiretoko Peninsula with a mountain range forming the backbone of the peninsula
photo by Shiretoko Shari-cho Tourist Association

Utoro Port, Shiretoko
photo by Shiretoko Shari-cho Tourist Association

Drift ice can usually be seen from January until early April.　its peak season is February. Today seasonal ice drift in Hokkaido attract many tourists with Icebreaker cruises, guided tours to walk and swim in the icy ocean.

sea ice, Shiretoko
photo by Shiretoko Shari-cho Tourist Association

ice hummocks, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

ice hummocks, Shiretoko
photo by Shiretoko Shari-cho Tourist Association

ice slush, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

sea ice, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

pancake ice, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

Brash ice viewed from Mombetsu Okhotsk-tower (http://www.o-tower.jp/)
photo by 動物写真集（アザラシ・シロクマ・旭山動物園）

pack ice like an anvil, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

mirage, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

pack ice, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

However observations of drift ice started to ensure the safety of navigation. Sea ice is a barrier to shipping, and making it impossible for fishing vessels to access fishing grounds. Abashiri Weather Station(current Abashiri Local Meteorological Observatory) has observed drift ice since 1892. The Ice Information Center by 1st Regional Coast Guard Headquarters provides information about drift ice in coastal waters off northeastern Hokkaido.

The following web site provides information on drift ice for tourists:

http://www.noah.ne.jp/ice/index.html
photo by Shiretoko Shari-cho Tourist Association
http://www.shiretoko.asia/world/index.html

pack ice and Oshinkoshin Falls bus stop, Shiretoko
photo by Shiretoko Shari-cho Tourist Association

pack ice, Shiretoko
photo by Shiretoko Shari-cho Tourist Association

pack ice, Shiretoko
photo by 動物写真集（アザラシ・シロクマ・旭山動物園）

ice hummocks, Abashiri
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

Cape Puyuni, Shiretoko

photo by Shiretoko Shari-cho Tourist Association

fast ice viewed from Yuhidai, Shiretoko

photo by Shiretoko Shari-cho Tourist Association

Cape Puyuni, Shiretoko
photo by Shiretoko Shari-cho Tourist Association

On the other hand, drift ice is the key driver of the coastal waters' ecosystem. Fresh water of the Amur River flows into the surface layer of the Sea of Okhotsk. Suraface sea water diluted with river water freezes more easily than ordinary sea water. Salt gets left in the liquid as salt water starts to freeze. The concentrated salt water sinks to the ocean bottom resulting in a mixing of the layers. Dense salt waters bring cold, nutrient-rich deep waters to the ocean surface, replacing nutrient-depleted surface water. The nutrient-rich upwelled water fosters the intense growth of phytoplankton called ice algae, which live in and under the drift ice is the foundation of the bountiful marine food web. Krill feeds on phytoplankton that grows on the underside of sea ice and provides an important food source for sea creatures.

Clione limacina
photo by 網走市観光課提供 (Abashiri City Hall Tourism Division)

Clione limacina, known as sea angel, are carried to the Sea of Okhotsk by the northern coast of Hokkaido, clinging to the undersides of the ice. Its earliest-stage larvae feed on phytoplankton and adults feed exclusively on a small herbivorous sea snail, Limacina helicina. They are pray for salmons. Visitors can also see them at the Okhotsk Ryuhyo(drift ice) Museum (https://www.ryuhyokan.com/)