The number of ships waiting to enter the biggest U.S. gateway for trade with Asia reached the highest since the pandemic began, exacerbating delays for companies trying to replenish inventories during one of the busiest times of the year for seaborne freight.

Forty-four container carriers were anchored and awaiting a berth space outside the twin ports of Los Angeles and Long Beach, California, as of late Friday, topping the record of 40 initially set in early February, according to officials who monitor marine traffic in San Pedro Bay. The average wait rose to 7.6 days, from 6.2 in mid-August, according to L.A. port data.

Vessels are lining up because imports are pouring into the world’s largest economy just as inland transportation — like trucking and railroads — contends with its own bottlenecks of shipping containers that aren’t being moved fast enough into distribution centers and warehouses.

Labor shortages are part of the problem, but companies are also trying to stock up ahead of the year-end holidays. August and September are key months for shipping goods out of China before that country’s Golden Week holiday in early October.

On top of those issues, importers that rely on goods from Asia in particular have experienced virus-related shipping disruptions like the one Mike Witynski, the chief executive officer of Virginia-based discount retailer Dollar Tree Inc., shared on a conference call last week. 

“One of our dedicated charters was recently denied entry into China, because a crew member tested positive for Covid, forcing the vessel to return to Indonesia to change the entire crew before continuing,” he said. “Overall, the voyage was delayed by two months.”

With ships thrown off schedule and most of them fully laden with boxes of goods, container ports on both U.S. coasts are experiencing record volumes that they’re having difficulty handling over a sustained period. Just off the coast of Georgia, for instance, Bloomberg mapping data showed at least a dozen cargo ships anchored in a cluster with the Port of Savannah listed as their destination.