Port of Oakland marine terminal operations halted as longshore workers took the day off for a union meeting. That means no gate, yard or vessel work on the 8 a.m. to 5 p.m. shift, the Port said.  Vessel operations will stop on the evening shift as well under a month-old suspension of nighttime activity by terminal operators. The decision not to work comes in the ninth month of contract negotiations between dockworkers and terminal operators at 29 West Coast ports.  Full operations are expected to resume at the Port tomorrow, Feb. 20. "The decision not to work is damaging to shippers who rely on the Port of Oakland to move their cargo, and to the thousands of people who depend on the Port for their livelihood," said Port Maritime Director John Driscoll.  "Disruptions such as this one cripple our ability to support global trade and the economy of the Bay Area." According to reports, the longshore union is taking the day off to conduct a monthly meeting.  The meetings, known as "stop-work" meetings, have long been part of labor-management contracts at West Coast ports.  Traditionally, however, those meetings have been held at night.  Today's day-shift meeting coincides with the Port's peak period of activity. The work stoppage means containers will not be loaded or unloaded on the 12 vessels at berth.  It also precludes the release of import containers or acceptance of exports for overseas shipment.