Delta and Dawn, also known as theDelta whales, are twohumpback whales, a mother and her calf, who enteredSan Francisco Bay in early May 2007. They swam up theSacramento River approximately 90 nautical miles (170 km) upstream from theGolden Gate,[1][2] about 20 miles (32 km) further inland thanHumphrey the Whale had gone two decades earlier. Under theEndangered Species Act, Californiastate officials were required to rescue the animals.[1] Their journey was thought to be the longestfreshwater incursion by humpback whales ever documented.[3]
Staff from theMarine Mammal Center, researchers,Coast Guard personnel, and volunteers tried several methods to coax Delta and Dawn back downriver.[1][4] The Marine Mammal Center was appointed by theCalifornia Office of Emergency Services as the lead rescue agency.[3] Officials played recordings of thesounds of other humpback whales feeding and socializing to lure them,[5] and banged on submerged metal pipes and sprayed high-powered blasts of water to repel them, but it is not clear whether any of these were particularly effective.[6] There was heightened concern for the whales' well-being this time, because both of them had sizable gash wounds, most likely made from boatkeel orpropeller strikes.Veterinarians from the Marine Mammal Center andWHOI administeredantibiotics to the whales to help heal these deep open wounds, and they took samples of skin lesions incurred during the whales' extended time away fromseawater to analyze them for possiblefreshwaterbacterial infection. This was the first time antibiotics had been administered to free swimming whales in the wild.[7][8]
On May 20, after languishing for six days in theSacramento Deep Water Ship Channel, the whales finally started moving. They were spotted the next day about 20 miles (32 km) downstream, just upriver fromRio Vista, where they lingered for several days, seemingly hesitant to pass under theRio Vista Bridge.[9] On May 27 they were on the move again and were spotted the next day another 20 miles (32 km) downstream in thesaltier waters ofSuisun Bay, just 40 miles (64 km) or so from the ocean, but again their circling movements seemed to indicate a reluctance to pass beneath a bridge, actually a trio of bridges this time atBenicia. On May 29, however, they again moved quickly, passing under theBenicia Bridge in the morning and swimming through theCarquinez Strait and past yet another pair ofbridges. By late afternoon they had continued throughSan Pablo Bay and were circling just beyond theRichmond-San Rafael Bridge nearTiburon. They were last spotted at sunset that night, within 10 miles (16 km) of theGolden Gate Bridge and the open ocean beyond.
A small controversy arose over what to call the whales as soon as they were spotted far enough upriver to warrant significant attention. Besides being called "the Wayward Whales," they were also dubbed "Momma" and "Baby", "Rio" and "Vista", and "Delta" and "Dawn" (for theSacramento-San Joaquin River Delta and the 1970s song "Delta Dawn"). California's Lieutenant Governor,John Garamendi, was the one to bestow the last pair of names upon the whales.[4][10] Their names were inspired by local media contests throughout the region.[4]
The story of the wayward whales inspired Stefanie Cruz, a news anchor for Sacramento-based television stationKOVR, to write a children's book based on the tale,Delta & Dawn: Mother and Baby Whales' Journey, which was released November 2007. The whales were alsoparodied by a cartoon.[11]
