Beginning next week, a fine of 100 U.S. dollars a day per container will be levied against shipping companies that unload cargo too slowly in the two busiest ports in the United States, Port of Los Angeles (POLA) and Port of Long Beach (POLB).

The twin ports said in a joint statement Monday that arriving containers scheduled to be moved by trucks would be allowed to stay for nine days before fines begin, and that containers moving by rail can stay at the ports for three days.

"Beginning Nov. 1, the ports will charge ocean carriers with cargo in those two categories 100 U.S. dollars per container, increasing in 100 U.S. dollars increments per container per day," the statement read.

"The terminals are running out of space, and this will make room for the containers sitting on those ships at anchor," POLB's Executive Director Mario Cordero said in a statement.

It's the latest move aimed at relieving the logjam of cargo ships, which has disrupted global supply chain, according to Yahoo News.

"The backlog prompted the Biden administration to allow the port complex to operate 24 hours a day to try to get goods unloaded and out to consumers," Yahoo noted, one of a number of recent actions by the private sector and government officials to keep goods flowing into the country in a timely fashion.

The size of cargo ships has doubled since 2000, according to Costamare.com, and today more than a dozen super-sized cargo ships hold more than 20,000 TEUs (20-foot equivalent units of containers), meaning that fines up to 10,000 U.S. dollars a day could be levied against the shipping companies starting Nov. 1, the ports announced.

However, with reports of union crane operators intentionally slowing the offloading of containers, it is unclear how these fines will be collected or even if they are legally tenable, experts said.

Fees collected from stagnant cargo shippers will be re-invested by the two ports for programs designed to enhance efficiency, accelerate cargo velocity, and address congestion impacts throughout the San Pedro Bay, the ports said in the statement, noting "the policy was developed in coordination with the Biden-Harris Supply Chain Disruptions Task Force, U.S. Department of Transportation and multiple supply chain stakeholders."

"I support the actions taken by the ports of Los Angeles and Long Beach today to charge ocean carriers for lingering containers on marine terminals. These actions aim to expedite the movement of goods and reduce congestion in our ports," John D. Porcari, Port Envoy to the Biden-Harris Supply Chain Disruptions Task Force, said in the statement.

"As our economy continues to grow, increased demand and disruptions caused by the pandemic are putting our supply chains to the test," Porcari said.

Before the pandemic-induced import surge began in mid-2020, on average, containers for local delivery sat on container terminals under four days, while containers destined for trains dwelled less than two days.

"But those numbers have increased significantly over the last year, making it difficult to clear cargo off the terminals and bring in ships at anchor, contributing to the backup," gCaptain, a website devoted to maritime and offshore management since 2008.

"While we've seen new records set in terms of throughput this year at West Coast ports, we need more players throughout the supply chain to keep stepping up. The federal government will continue to bring together private companies and stakeholders from across the supply chain and serve as an honest broker helping to surface solutions like this to address supply chain disruptions," he added.

About 40 percent of all shipping containers entering the United States come through the Los Angeles and Long Beach ports.

"With the escalating backlog of ships off the coast, we must take immediate action to prompt the rapid removal of containers from our marine terminals," Cordero said. "The terminals are running out of space, and this will make room for the containers sitting on those ships at anchor."

"As of today, the ports of Los Angeles and Long Beach had 102 containerships in port, including 73 at anchor or in hold areas and 29 at berth," gCaptain posted Monday, noting that "the Port of Long Beach has also moved to relax stack height limit restrictions, allowing stacks to be 4 containers high" when stored.