Nearly five months after the coronavirus pandemic shut down the cruise industry, more than 12,000 crew members remained on ships in U.S. waters, according to the Coast Guard. That’s down from more than 70,000 in May.

The Coast Guard “is tracking 57 cruise ships moored, at anchor, or underway in vicinity of a U.S. port, or with potential to arrive in a U.S. port, with approximately 12,084 crew members,” Brittany Panetta, a lieutenant commander and spokesperson for the U.S. Coast Guard, told USA TODAY.

The Coast Guard says that number includes an estimated 209 Americans who are spread out among 37 of the ships. But the Centers for Disease Control and Prevention said as of Wednesday that the agency knew of 53 U.S. crew members on 22 cruise ships in U.S. waters. It’s unclear how many of those crew members are actually stuck vs. working.

“We do not know if these 53 crew members are considered essential for the safety and seaworthiness of the ship and need to remain on board or if they are working with their cruise lines to be repatriated,” CDC spokesperson Jason McDonald said, noting the agency “is allowing crew members to disembark from all cruise ships in U.S. waters.”

Cruise ships always require at least “minimum manning” for upkeep and to maintain basic onboard operations, though the number needed to keep things running varies by ship and is determined by the ship’s flag country,McDonald said.

As far as disembarking U.S. crew members who aren’t needed, McDonald said it’s the responsibility of cruise lines, which must meet criteria to determine whether crew members can use commercial or noncommercial transportation.

Cruise industry trade group Cruise Lines International Association (CLIA) tracks crew members differently than the Coast Guard, estimating how many around the world are actually trying to get home. The group represents 95% of ocean-going cruise lines.

“Our best estimate of the number of seafarers on cruise ships still awaiting repatriation is approximately 5,000, based on a survey of our major cruise line members,” Bari Golin-Blaugrund, senior director of strategic communications for CLIA, told USA TODAY Thursday.

Some crew members face repatriation challenges.

United Nations’ Secretary-General António Guterres’ spokesperson called the issue a “humanitarian and safety crisis.” Stéphane Dujarric urged countries to allow stranded seafarers to repatriate in a June statement.

The reason it’s been so difficult? Government-imposed travel restrictions, according to the International Maritime Organization.

“There are a lot of countries you would normally take air transportation or might find yourself going from home port to home country on ground transportation,” Goldstein said. “Borders started to be closed, and (crew members) couldn’t access normal routes.”