OAKLAND (CBS SF) — While loaded cargo traffic saw a slight increase in April, officials warned Tuesday of a drop-off coming in May and beyond as shipments have been cancelled due to the coronavirus outbreak.

Port officials reported that April loaded container volume increased 1.4 percent compared to the same month last year. Export loads rose 3.6 percent, the Port said, while imports dipped 0.9 percent.

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But the outlook for the coming months is for reduced cargo volume.

Port officials said their future outlook is being influenced by 11 percent of scheduled Oakland vessel calls in May and June having already been canceled by shipping lines.

Ocean carriers worldwide are scrubbing voyages due to dwindling demand by shippers for vessel space. The culprit: a global economic downturn resulting from the pandemic.

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“Our April cargo performance was better than expected, but it was most likely a blip resulting from the release of pent-up demand when factories re-opened in China after being quarantined,” the Port said in a statement. “We’re faring better than some other ports, but our forecast in the coming months is overall volume throughput decline of 5-to-10 percent.”

The Port said exports leaving Oakland for overseas markets continue to be a bright spot midst the pandemic. Export volume has increased year-over-year in three of the past four months, according to Port data.

Officials said growth in exports to Southeast Asian markets has offset shrinking trade with China. Asian demand is strongest for U.S. farm goods.

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The Port said its total cargo volume – imports, exports and empty container shipments – declined 6.5 percent last month. Officials attributed the decline to a 29 percent drop in shipments of empty containers back to origin destinations.