After a series of work actions and terminal closures, operations at the ports of Long Beach and Los Angeles have “generally improved,” according to the Pacific Maritime Association.

But recent work actions had an impact on cargo movement, according to the group. The association, which represents terminal operators and shipping companies—many of which are foreign-owned—stated that coordinated work actions by union labor between June 2 and June 7 disrupted operations. The organization claims the union “refused” to dispatch lashers, who secure cargo for trans-Pacific sailings and unfasten arriving cargo.

“Without this vital function, ships sit idle and cannot be loaded or unloaded, leaving American exports sitting at the docks unable to reach their destination,” the PMA statement reads.

In an email Friday, a spokesperson for the International Longshore and Warehouse Union, which represents some 22,000 dockworkers at the 29 West Coast ports, said the union “does not have anything to share at this time.”

ILWU Local 13, which represents around 12,000 dockworkers in the San Pedro Bay, did not respond to a request for comment.

On June 2, terminals experienced a labor shortage and work slowdown. Local 13 leadership at the time stated workers took it “upon themselves to voice their displeasure with the ocean carriers’ and terminal operators’ position.”

On Monday and Tuesday, two terminals—Total Terminal International, the largest container terminal at the Port of Long Beach, and Pacific Container Terminal—closed for various shifts. The operators did not cite specific reasons for the closures, only that they were for normal operations reasons.

The alleged work actions and closures have resulted in delays for at least 10 container ships in and out of the ports of Long Beach and Los Angeles, according to the Marine Exchange of Southern California. The organization said the vessels are “delayed because of the labor shortage.”

“Some agencies either did not want to comment as to the labor shortage being the reason for vessel delays, or the emails we received containing schedules did not specify the reason for a delay,” said Richard Palmer, assistant maritime information manager for the Marine Exchange.

While the ships identified by the Marine Exchange were experiencing harsher delays, Palmer noted that “basically every container vessel is having their schedule pushed back by about a day or two.”

The union’s failure to dispatch lashers is part of a broader effort to withhold labor from the docks as contract negotiations between the two groups continue after more than a year, PMA claims.

On Wednesday, the organizations stated, the ILWU refused to fill 260 out of 900 jobs ordered at the San Pedro Bay ports. In total, 559 longshore workers were denied work opportunities at the dispatch hall, PMA claims.

“Each shift without lashers working resulted in more ships sitting idle, occupying berths and causing a backup of incoming vessels,” the PMA statement reads. “With the ILWU’s decision to stop withholding labor, terminals at the Ports of Los Angeles and Long Beach have for now averted the domino effect that would have resulted in backups not seen since last year’s supply chain meltdown.”

Contract negotiations began in May of last year, with the previous contract expiring months later on July 1. The groups agreed for work to continue under the old conditions with no strikes, slowdowns or lockouts. But as talks dragged on toward the year mark, workers began taking action.

Earlier this year, employers accused workers of weaponizing lunch breaks to slow down cargo movement. Then, they claimed the union was delaying standard dispatch practices and “red tagging” equipment to slow work.

In April, 11 of 13 terminals between LA and Long Beach closed for a day due to labor shortages. The union claimed workers were merely attending a meeting and observing Good Friday—two events that historically have not effectively shut down the nation’s largest port complex.

As a result of the uncertainty around labor negotiations, importers began shifting cargo away from the West Coast ports in August, Port of LA Executive Director Gene Seroka said during a Wednesday harbor commission meeting.

“Some folks continue to be very skittish about this marketplace,” Seroka said. “We all understand the cargo has moved away from us in part because of import and exporters trepidations about labor disruption.”

The shift resulted in the Port of New York and New Jersey overtaking Long Beach as the second-busiest container port in the nation last year—a title it continues to hold as of the end of April.

“We’ll continue to do everything we can to encourage both sides to stay at the table, working on the details, and coming up with good resolutions,” Seroka added. “And then work collectively to bring as much of the cargo back here to Southern California that we can.”

2 container terminals at Port of Long Beach closed Monday, at least 1 to be closed Tuesday