Last Updated 7:30 p.m. ET
A strike at the ports of Los Angeles and Long Beach continued for the fourth day on Friday despite efforts to end the walkout that has idled most of the nation's busiest cargo complex.
Seven of eight terminals in Los Angeles and three of six in Long Beach were closed to cargo container traffic as 10,000 dockworkers refused to cross picket lines set up by union clerical workers who claim shippers are outsourcing their jobs.
The strike began with 70 workers, and now all 800 members of their union are on strike.
There were a handful of picketers at each terminal on Friday, said Phillip Sanfield, Los Angeles port spokesman.
Combined, Los Angeles and Long Beach handle 40 percent of the nation's import trade.
"There's probably about $1 billion worth of goods that come through this port every day, and we've probably got about 900,000 people in the southland whose jobs are tied to the activity going through this port," Geraldine Knatz, the executive director of the Port of Los Angeles, told CBS News' John Blackstone.
"If the ships are not working, the truckers are not working, the warehouse people are not working, it will ripple through the supply chain," Knatz said. She said that even a very short delay can mean stores may not get a shipment on the day they expect it.
The ports are clogged with 16 ships waiting to be unloaded, while another six are anchored off the coast.
The walkout involves clerical workers from a chapter of the International Longshore and Warehouse Union. Dockworkers are a separate unit of the same union.
The striking workers handle all the paperwork that gets cargo from the port to the rest of the country and earn an average of $85,000 a year, Blackstone reported. They say their jobs, most of which are done on a computer, are being sent to other countries.
The clerical workers' contracts with 14 terminal operators expired two years ago. Ongoing contract talks broke off on Monday then resumed on Thursday, ran until midnight and were scheduled to continue on Friday.
"In the last five years, we've lost 51 jobs and during negotiations they would like to lose another 71," Trini Thompson, who is on the negotiating team for the unions, told Blackstone. "So that's a large impact on us."
The chief negotiator for the shippers remained hopeful about a resolution, saying the talks have been professional and courteous.
"There's a mutual commitment to go forward," said Stephen Berry of the Los Angeles/Long Beach Harbor Employers Association. "The employers remain hopeful that there will be a quick resolution and we can get the cargo flowing again."
Berry told CBS News that the employees have "guaranteed jobs for life."
"We have a no-layoff clause," he said. "There's probably 25 million Americans who are looking for work right now who wish they had a no-layoff clause."
There was no immediate word on how much the strike is costing the ports. November generally is a slower time for the ports because most holiday goods already have been handled.
However, there were concerns that a continued widespread strike could prompt retaliation from terminal operators. A bitter 10-day lockout at a number of West Coast ports in 2002 caused an estimated $15 billion in losses.
That strike ended when then-President George W. Bush ordered the docks reopened. The nation's largest retailers' group has asked President Barack Obama to help end the current strike.
Shipping companies deny any outsourcing and have offered to boost average annual pay from $165,000 to $195,000 and grant 11 weeks of paid vacation, Berry said.
The shippers claim the union wants contract language to permit "featherbedding" -- the practice of requiring employers to call in temporary employees and hire new permanent employees even when there is no work to perform.