Method 1: Charter the Hokkaido University School of
Fisheries Sciences Training Ship Ushio-maru and a local fishing boat to collect
the larvae of Ammodytes sp. with a plankton net and its food that is plankton with a bottle sampler.
Method 2: Conduct a three-year survey by measuring
water temperature/salt content and seawater density every two weeks using an
oceanographic device called a CTD.