A jump in shipments of agricultural products helped cargo volumes between Oahu and six neighbor island ports maintain their upward trend in the first quarter, interisland shipper Young Brothers reported Monday.

Shipments rose 4 percent during the first three months of the year compared with the same period a year earlier. It was the fourth consecutive quarterly gain, according to Young Brothers. The last decline was in the first quarter of 2013 when shipments fell by 3.9 percent.

Young Brothers President Glen Hong said despite the steady gains over the past year shipping volumes have still not recovered fully from the last economic downturn. Hong said he will maintain a cautious outlook until he is convinced the recovery is firmly established.

"Going forward our quarterly comparisons will be tested since it was in the second quarter of 2013 when cargo volumes began experiencing steady growth," Hong said.

Cargo volumes rose at four neighbor island ports during the first quarter — Maui, Hilo, Kawaihae and Lanai. They declined at the ports on Molokai and Kauai.

The report tracks cargo volumes using a standard unit of measurement called "container/platform equivalents," or CPEs. Young Bros. uses the CPE measurement so it can compare cargo volumes across different sizes of containers.

For the first quarter the volume of interisland cargo totaled 32,384 CPEs in the first quarter compared with 31,144 CPEs in the first quarter of 2013.

By category, shipments of agricultural products rose 4.8 percent statewide following a decline of 0.4 percent during the fourth quarter of last year.

"We saw a rise in cargo across the diverse range of agricultural products, particularly in the area of local beef and taro," Hong said. "We also are starting to see more of these types of local products being shipped by smaller scale farmers as demand increases. Other types of produce, plants and aquaculture products also experienced growth in volume."

Shipments of agricultural products increased at every port during the quarter except Maui. Young Brothers provides a discount of 30 percent to 35 percent for locally grown products.

Several other industry segments saw notable increases in shipments, including rental automobiles, renewable energy equipment, construction services equipment and manufacturing equipment. There were declines in shipments of food and beverages.