Though many may not know it, the right whale is the Bay State’s official marine mammal, and the first Thursday of May is Massachusetts Whale Awareness Day. To mark the occasion, there will be a life-size, inflatable whale named Delilah in front of Plymouth Memorial Hall this Saturday. And the Whale and Dolphin Conservation, an international nonprofit with offices in Plymouth, will be holding its inaugural Race to Save a Species 5K and Whale Awareness Day party that day. The race is scheduled to start at 9 a.m. from Plymouth Memorial Hall at 83 Court St., and runners can register online by clicking the “Race to Save a Species” link on www.whales.org. The party is free to attend and will take place from 9:30 a.m. to noon. It will feature educational activities, raffles, and live music. Proceeds from the event will support the organization’s efforts to protect the North Atlantic right whale, since there are fewer than 500 left.