Every little bit helps. The Port of Los Angeles saw a less than 1 percent increase in container cargo movement last month compared to the year-ago period, though the increase was due to a large volume of empty containers heading back overseas.

More than 694,790 containers moved through the port in May, a 0.8 percent bump from last year, according to port officials.

The number of imported containers fell last month by 0.8 percent, to nearly 348,430. Exported container cargo volume dropped 3.5 percent to about 152,900 containers. Container cargo movement is also down 4 percent for the first five months of the year compared to the same period last year. Pushing volume into positive territory were empty containers shipped back overseas. May empties were up 7.9 percent over year-earlier volume.

The May numbers showed an improvement from April, when container cargo volume was off 6.1 percent from the year earlier. Port officials attributed that drop to a rush to bring in goods last year in advance of a possible slowdown at the ports of Los Angeles and Long Beach as shipping lines and dock workers began contract negotiations.