Strong increases in retail container volumes are expected into the holiday season despite talk of a possible strike at East and Gulf Coast ports, according to the monthly Global Port Tracker report released by the National Retail Federation and Hackett Associates.

“Retailers are bringing in more merchandise for the holiday season this year. The question at some ports is whether longshoremen will be on the docks to unload it,” said Jonathan Gold, NRF vice president for supply chain and customs policy.

“Regardless of what happens with contract talks,” said Gold, “retailers have contingency plans in place to ensure that merchandise reaches store shelves in time and that there is no disruption for shoppers.”

Talks between the International Longshoremen’s Association (ILA) and United States Maritime Alliance (USMX) broke down in August, and at least one major ILA local has authorized a strike if a new contract for East and Gulf Coast ports isn’t agreed on by the time the current pact expires September 30. Labor and management have agreed to meet again under the supervision of the Federal Mediation and Conciliation Service.

Retailers are considering a variety of contingency plans, including diverting cargo to West Coast ports, which are represented by a separate union and not affected.

U.S. ports followed by Global Port Tracker handled 1.41 million twenty-foot equivalent units (TEUs) in July, the latest month for which after-the-fact numbers are available. That was up 2.2 percent from June and 2.5 percent from July 2011.

August was estimated at 1.43 million TEU, up 4.4 percent from last year. September is forecast at 1.49 million TEU, up 8.5 percent; October at 1.48 million TEU, up 11.7 percent; November at 1.32 million TEU, up 1.9 percent; and December at 1.25 million TEU, up 2.7 percent.

The new year is expected to start lower – January 2013 is forecast at 1.23 million TEU, down 3.8 percent from January 2012.

The first half of 2012 totaled 7.7 million TEU, up 3 percent from the same period last year. For the full year, 2012 is expected to total 16 million TEU, up 4.2 percent from 2011.

All the numbers above reflect this month’s addition of Port Everglades in Fort Lauderdale, Fla., to the list of harbors covered by Global Port Tracker, with 2011 numbers adjusted to provide accurate comparisons.

Hackett Associates Founder Ben Hackett said shipping patterns are being affected by the possibility of a strike.

“Importers anticipating a strike placed orders early to ensure that their goods would arrive in time, and are most likely also switching deliveries for the East Coast to the West Coast instead,” Hackett said. “As a consequence, August appears to have been a relatively good month, and September will also be above the norm. The West Coast will benefit at least through October as cargo is diverted.”

Global Port Tracker, which is produced for NRF by the consulting firm Hackett Associates, covers the U.S. ports of Long Angeles/Long Beach, Oakland, Seattle and Tacoma on the West Coast; New York/New Jersey, Hampton Roads, Charleston, Savannah, Port Everglades and Miami on the East Coast, and Houston on the Gulf Coast.