A Coast Guard K-9 unit from Maritime Safety and Security Team New York patrolled Boston’s waterfront Sunday morning as an increased security measure leading up to the Boston Marathon.

The team included Rruthie, a 3-year-old Belgian Malinois, who is specially trained to sniff out various threats. The New York team is working in conjunction with Boston’s Maritime Safety and Security Team throughout the weekend.

“Our presence alone can act as a deterrence for someone planning to do harm,” said Petty Officer 3rd Class Richard Barone, Rruthie’s handler and a maritime enforcement specialist.

The Coast Guard will remain a visible security presence on the waterfront leading up to and during the marathon.