The Seattle and Tacoma seaports recently marked more than a half century of moving Mazda vehicles through the Pacific Northwest. The carmaker first started importing vehicles through the region on April 14, 1970 – first through Seattle, and then through Tacoma almost a decade later – making Mazda the longest-running automobile to move through Tacoma. So far, roughly 1.9 million Mazda vehicles have been processed through the Northwest Seaport Alliance gateway, according to data from the ports. The NWSA estimates that every Mazda ship call generates an average of 40 to 45 longshore worker jobs, as well as other supply…