Amid a backlog of shipping containers that have amassed during recent congestion at the twin ports of Los Angeles and Long Beach, mayors of both cities say they will work together rather than compete on new efforts aimed at addressing how changes in ocean trade affect the ports.

Los Angeles Mayor Eric Garcetti and Long Beach Mayor Robert Garcia said in a joint press conference Monday that officials from the two ports have submitted a proposal to the Federal Maritime Commission that calls for collaboration on several supply chain issues.

The issues include truck chassis supply and storage, better coordination of when ships call on the ports and wait times for trucks at port terminals. Other issues involve marketing, environmental issues, security, ways to reduce congestion and legislative advocacy. The proposal is open for public comments, which must be filed by Wednesday.

After months of congestion at the two ports caused by operational issues and tense labor negotiations that ended late last week, officials in both port cities are hoping additional cooperation will help keep Los Angeles and Long Beach as the busiest port complex in the nation. Some port customers started moving goods through other ports after an ugly West Coast port shutdown in 2002, something local leaders hope to minimize this time around.

“The changing face of seaborne trade is impacting major ports around the world,” said Port of Los Angeles Executive Director Gene Seroka. “In order to keep our competitive edge, it makes good sense for our ports to strategize and help facilitate changes in the supply chain that will enhance Southern California’s competitive advantage.”