"That on the application of the owners, Messrs Thomas Dixon and Sons a new street on their property off Solway Street and Derwent Street be named Sark Street". (1st April 1891).
A surmise - this street may be named to fit in with the many other streets in the area named after rivers. There is the River Sark which forms part of the Western border between Scotland and England, most of the river is in Scotland.