LONG BEACH—March was the Port of Long Beach’s busiest month in its 110-year history and only the third month that the port handled more than 800,000 20-foot equivalent units in a single month, officials announced April 8.   March is traditionally a slow month for the port, officials said, but this past March, the dockworkers and terminal operators moved a total of 840,387 20-foot equivalent units. The previous busiest month was December 2020, when 815,885 units were moved.   “Although the pandemic is receding, consumers are spending less on travel this year and turning toward online retail in unprecedented numbers to purchase exercise equipment, office furniture and home improvement items,” said Mario Cordero, executive director of the Port of Long Beach. “The demand for e-commerce is happening more quickly than we anticipated, but we will continue to collaborate with our industry stakeholders to catch up with the unprecedented cargo volume …