Castro joined the Grand Valley faculty in 1973. He was a champion for ethics, teaching courses on the topic and establishing the Center for Business Ethics in Seidman College of Business. The center is a roundtable of CEOs, faculty and other community leaders who meet to discuss ethical issues related to business. Castro also initiated and led seminars with CEOs who read Plato and then discussed the ethical applications of his works to businesses.
Castro joined the faculty of what was then Grand Valley's William James College in 1973, serving in that position until 1983, when he moved to the Seidman School of Business as professor of management. He also served as assistant dean for seven years.
Castro was honored in 1997 in Lansing by the Michigan Association of Governing Boards for his leadership in teaching, research and service. He also volunteered for many community causes, serving on boards and contributing to area organizations like Second Harvest Gleaners.
