Calum joined the Mariners on a loan deal from Everton during the January transfer window.
The 20-year-old striker has been with the Toffees since the age of six, progressing through the academy and signing a two-year professional deal in July 2014. Calum has since signed an extension to his deal with the club.
During the 2013/14 season, Dyson featured regularly during the club's Under-18 title-winning campaign, scoring 6 goals and providing 10 assists.
Made his Town debut v Luton Town on 04.02.17.