Ricker[note 1] was a Canadian Coast Guard offshore fisheries research vessel.

The ship was originally constructed as the commercial fishing trawler Callistratus, but was purchased by the Government of Canada in 1984 and converted to a fisheries research vessel and renamed W.E.

The vessel entered service with the Department of Fisheries and Oceans in 1986 and was transferred to the Canadian Coast Guard in 1995 after the two fleets were amalgamated.

[3] The vessel was used as a factory trawler by the Prince Rupert Fishermen's Co-operative Association participating in emerging North Pacific fisheries (North Pacific hake, turbot and rockfish) resulting from the extension of Canada's exclusive economic zone to 200 nautical miles (370 km) offshore.

[2][5] In 1995, in an effort to combine tasks, administration and savings in both ships and funds, the Fisheries and Oceans and Canadian Coast Guard fleets were merged under the command of the Canadian Coast Guard.

[1] In September 2009 the Department of Fisheries and Oceans announced invitations for contracts to replace several of the Coast Guard's research vessels, including W.E.

Ricker was put up for sale for scrap only due to the vessel's poor condition.