THE Port of New York and New Jersey (PANYNJ) displaced the Port of Los Angeles and the Port of Long Beach in August as America's the top container port by volume, reports Fort Lauderdale's Maritime Executive.

PANYNJ moved more than 843,000 TEU in August, setting a new August record, according to CNBC. Long Beach moved about 807,000 TEU, just barely edging out Los Angeles' 805,000 TEU.

The cross-country switch is partly due to shipper anxiety about ongoing talks between the International Longshore and Warehouse Union (ILWU) and the Pacific Maritime Association (PMA), the employers' bargaining organisation for west coast terminal operators.

The previous labour agreement ended in July, and talks on the key sticking points - wages and terminal automation - have not made progress in recent weeks. Some shippers are concerned that the possibility of a disruptive strike is on the rise.

Already, ILWU dockers have refused to work some vessels at the semi-automated Pier 400 in LA over safety concerns.

Reminiscent of the Port of Portland reefer plug dispute, the Wall Street Journal reports that a long-running disagreement between the ILWU and the International Association of Machinists and Aerospace Workers appears to be on the contract bargaining table too.

All these factors have shippers looking to the US east coast to hedge their bets. In addition to PANYNJ, Savannah and Houston are seeing increased numbers, with volume at both ports ticking up in August.

Port of Los Angeles executive director Gene Seroka chalked up some of the decline in August cargo volume to changing trading patterns, with shippers bringing their fall and winter season cargo in early to ensure against disruption.

"Additionally, inflationary concerns and elevated inventory levels have made some retailers and ecommerce sellers more cautious," he said.

The good news for the Port of LA is that its headline-making backlog is nearly gone. Mr Seroka said that compared with earlier this year, the number of containerships waiting for a berth at the port is down 90 per cent.