The federal government needs to invest more in West Coast ports, said the head of the Port of Los Angeles, which is the nation’s biggest gateway to Asia and is grappling with record backlogs.

To understand why more than 100 containerships are waiting to enter U.S. ports from Southern California to Savannah, Ga., it helps to keep tabs on the congestion that’s building at another key junction of freight transportation: rail yards.

EQT Infrastructure, an arm of alternative-asset manager EQT AB, is exploring a sale of its 90% controlling stake in Fenix Marine Services, which operates a container terminal in the Port of Los Angeles, according to people with knowledge of the matter.

As retailers ramp up inventory for a fast-approaching holiday shopping season, experts worry that an already overextended domestic supply chain will be further tested amid overseas ports’ struggles with the COVID-19 delta variant, rising shipping prices and trucking’s persistent and growing driver shortage.

Imported goods continued to flood into the U.S. in July as the nation’s ports produced substantial container volumes.

More than six months into the economic recovery, the nation’s ports on the Pacific and Atlantic coasts continue to see record or near-record cargo loads, and port officials and economists forecast the substantial numbers likely will continue well into 2022.

The Port of Los Angeles became the first port in the Western Hemisphere to process 10 million container units in a 12-month period, reaching the milestone on June 10.

For the last nine months, ports have seen record container volumes with movement limited and more supplies needed. As a lynchpin of our supply chain, managing a port requires high-functioning information systems to predict and plan for supply and demand as well as communicating with every link in the value chain.

Imported cargo shipments to the U.S. are expected to remain at a record or near-record levels for several more months as consumer spending continues to restart the pandemic-damaged economy. But industry experts say all of that buying is clogging an already overtaxed supply chain.

Ship congestion outside the busiest U.S. gateway for trade with Asia eased over the past week, with the number of container vessels waiting to enter the twin ports of Los Angeles and Long Beach staying below 20 for five straight days.