Complex sentence: The Port is governed by a seven-member Board of Port Commissioners; one commissioner each is appointed by the city councils of Chula Vista, Coronado, Imperial Beach and National City, and three commissioners are appointed by the San Diego City Council.
Split into simpler sentences: The Port is governed by a seven-member Board of Port Commissioners. One commissioner each is appointed by the city councils of Chula Vista, Coronado, Imperial Beach and National City, and three commissioners are appointed by the San Diego City Council.