Four ferry trips between Rockland and Vinalhaven will not run this weekend, the Maine Department of Transportation announced Friday.

The trips on the Maine State Ferry Service boat Capt. Richard G. Spear were canceled after an employee tested positive for COVID-19. It’s the second time in the past month that ferry service between Rockland and an island community has been significantly impacted by the virus.

“This employee’s absence, coupled with ongoing staffing challenges, means the MSFS does not have enough crew members to staff every regularly scheduled run this weekend,” Paul Merrill, spokesperson for MDOT, said in a statement.

The 4:30 p.m. trip Friday from Rockland to Vinalhaven is canceled. On Saturday, the 7 a.m. trip to Rockland and 4:30 p.m. trip to Vinalhaven will not run. On Sunday, all trips on the Capt. Richard G. Spear are canceled except the 4:30 p.m. boat from Rockland to Vinalhaven.

The runs on the Capt. E. Frank Thompson are expected to stay on schedule.

As many as nine ferry runs between Rockland and North Haven were canceled from April 29 to May 1 after multiple crew members tested positive for COVID-19. Without those boats, some islanders could not return to North Haven, prompting the school to let students out early because so many teachers were absent.

Vinalhaven, one of Maine’s largest islands, is located about 12 miles off the coast of Rockland. It has a year-round population of about 1,100.