Seattle announced Marsh's signing Monday. Financial terms of Marsh's deal were not released but he will receive a four-year contract. Marsh was taken with the 108th pick overall in the draft out of UCLA.
Seattle also signed tight end Rashaun Allen and guard Nate Isles, who both took part in the Seahawks' rookie minicamp last week on a tryout. Allen had only nine catches his senior season for Southern but is a big target at 6-foot-4 and 250 pounds. Isles was a starter on the offensive line at North Carolina A&T.
To clear roster spots, the Seahawks terminated the contract of tight end Travis Beckum and released cornerback Jimmy Legree.