SAVANNAH - Buoyed in part by labor woes on the West Coast, the booming seaports in Savannah and Brunswick saw another fiscal year of record-smashing amounts of cargo moving across their docks, the Georgia Ports Authority reported Monday.

The two coastal ports handled 31.69 million tons of cargo during the 2015 fiscal year that ended June 30. That's their greatest tonnage ever and an increase of nearly 8 percent from a year ago.

The tonnage figure includes a whopping 3.6 million units of containerized cargo - giant metal boxes used to ship consumer goods from electronics to frozen chickens - that moved through the Port of Savannah. That means containerized imports and exports jumped 17 percent from last year, when Savannah surpassed 3 million container units for the first time.

"It was a pretty amazing year for us," said Curtis Foltz, executive director of the ports authority.

Savannah benefited this past year from a labor dispute that was blamed for slowdowns at West Coast ports such as Los Angeles and Long Beach. Shippers ended up diverting cargo to the East Coast to avoid delays. And Georgia ports officials say Savannah was able to take on the extra business more efficiently than most others.

Foltz said he expects Savannah to see some permanent gains from the West Coast's woes. How many new customers stick around remains to be seen.

"We know there will be some of the cargo and accounts that will revert a portion of their business back to the West Coast," Foltz said. "We just don't know how much and we don't know when."

Imports made up 54 percent of the Georgia ports' business in fiscal 2015, while 46 percent of cargo was exported.

Break-bulk cargo including automobile and heavy machinery finished the fiscal year up 7.6 percent at a total 2.8 million tons. That included a record 714,021 units of autos and machinery, most of which moved through the Port of Brunswick. Liquid and dry bulk goods such as vegetable oil and wood pellets used to fuel power plants overseas were up 8 percent from the previous year, for a total of 2.9 million tons.

Foltz said the extra business led to the Georgia Ports Authority recording its highest revenues ever - more than $356 million.

Savannah has the fourth-busiest container port in the U.S. On the East Coast, it ranks No. 2 after the combined Port of New York and New Jersey.