Most of the crabs unloaded on Sado Island are snow crabs, which live on the deep sea floor at depths of 500m to 2,700m. Among the fishing grounds around Sado Island, the area southwest of the Ogi Peninsula and area northeast of Washizaki are deeper than 500m. Snow crabs flourish in these areas because the environment, ideal for snow crabs, has remained almost the same since the Japan Sea enlarged and deepened. The southwestern part of the Ogi Peninsula leads to the Toyama Trough, and the northeastern part of Washizaki leads to the Mogami Trough, forming a long area of deep depths. A large amount of snow crabs are found around these areas.

Sado Island is known as one of the best places to catch snow crabs in Niigata Prefecture. It takes around 10 years for a crab to grow to an edible size. Snow crab cuisine includes kani miso, a miso-like paste made from boiling crab innards, and fresh and flavorful meat. The best season for snow crab is from November to March.