Two federal biologists flew over the area Monday and found no sign of stranded or dead whales, but quite a few of the whales swimming freely.
"We saw a lot of alive belugas but we did not see any dead, floating or beached whales," said Barbara Mahoney, a National Marine Fisheries Service biologist who went looking for the whales Monday morning.
The whales were spotted by a pilot Saturday afternoon wallowing in a large mud hole. They were spotted again, still stuck, a couple of hours later.
Pictures taken on Saturday indicated the whales dug a hole in the mud when they got stranded on mud flats off the Birchwood area north of Anchorage, Mahoney said. All the whales were in the mud hole, except one that was lying on hard mud.
The stranding occurred during an abnormally low tide. Mahoney thinks the whales were likely stuck for several hours or more.
"They were just caught at the wrong place at the wrong time," she said.
Mahoney said it looks like the whales wiggled around in the mud before all the water was gone and were able to create a small pool for themselves. The water helps keep the animals cool, she said.
This time of year, the belugas chase silver salmon in the area.
Mass strandings are one of the biggest threats to the Cook Inlet belugas, which are listed as endangered under the federal Endangered Species Act. Adult male beluga whales are typically up to 15 feet long and weigh 3,000 pounds, exhibiting several vocalizations including squeaks and whistles.
The Cook Inlet belugas are considered a genetically distinct population as they don't mix with other beluga groups in Alaska. There are about 375 of them, down from approximately 1,300 in the 1980s.
Overharvesting by Alaska Natives is believed to have contributed to the downward slide but numbers continued to decline even after hunting was sharply curtailed in 1999.
In the last decade, there have been 15 reported strandings of beluga whales in Cook Inlet. On a couple of those occasions, it is believed that the presence of killer whales may have prevented the belugas from moving to deeper waters when low tide occurred.