The ports of Los Angeles and Long Beach posted gains in East Asia-related trade in the month of March, while ports in Oakland and the Northwest Seaport Alliance – consisting of the ports of Seattle and Tacoma – saw decreases, according to the Pacific Merchant Shipping Association’s latest West Coast Trade Report. Combined, the five major West Coast gateways processed 56.9% of all containerized import tonnage coming to the U.S. from Asia in March, up slightly from 56.8% the previous year, according to the report. “However, the Big Five’s combined share of the value of containerized imports from East Asia…