Certifier : 
Lloyds Register (Acoura)
Certified status : 
Certified since : 
13 May 2013
Certificate expires : 
12 Nov 2023


The Japanese scallop is a cold-water bivalve mollusc. It is naturally distributed in coastal, sub-Arctic areas of the eastern Pacific including the Japan Sea and southern Sea of Okhotsk, around Sakhalin Island, Hokkaido, and northern Honshu.

Japanese scallops are sessile (immobile) and live in shallow depressions dug into sandy, sandy-gravel and gravelly seabeds. They feed on phytoplankton and on detritus collected from the seabed. 

Japanese scallop grow relatively fast, reaching 2-5cm shell height in one year, increasing to 5-9cm and 16-80g by year two, 8-12cm and 60-170g by year 3, and 10-15cm and 110-300g by year three. Japanese scallops may reach 20cm shell height and weigh 1000g at 10 years of age.

Scallops are collected in the wild on hanging spat collectors, onto which the larvae (spats) attach themselves. They are then grown on using one of two methods:

• Hanging culture (Suika-shiki) on ropes/nets suspended in the water is undertaken in the Japan Sea and Funka Bay.

• Seabed ranching (Keta-Ami), cultivated on the seabed and collecting by dredging, takes place in the Sea of Okhotsk and Nemuro Straits.

Japanese scallop (Patinopecten (Mizuhopecten) yessoensis) image © Scandinavian Fishing Year Book