Beluga close-up, photo from NOAA, accessed via Wikimedia Commons.Residents of the middle Yukon River from Kaltag to Ruby have seen several groups of beluga whales over the past few weeks.Download AudioBeluga sightings so far upriver are uncommon but not unheard of. A group of belugas made it past Hughes on the Koyukuk River in the fall of 2001 – more than 550 miles from the ocean. And a single juvenile beluga was found dead over a thousand miles from the sea on the banks of the Tanana River near Nenana in 2006.Fish and Game Marine Mammal Biologist Lori Quakenbush in Fairbanks explains that going upriver is not a problem for belugas.“Depends on how shallow the water gets, how high the water levels are, how high they can go and whether there is anything interesting up there. If there are fish going up and they can catch the fish either along the banks or concentrated in certain area, that would certainly be a place of interest and belugas might go there. They are not obligated saltwater animals, fresh water is fine for them.”Quakenbush does not have a firm explanation for the apparent increase in belugas sightings on the Yukon this year. But elsewhere in the state, belugas have been known to escape into rivers to avoid one of their main predators.“One of the things that belugas have to worry about are killer whales, who are a major predator of the beluga. Killer whales are quite a bit bigger than belugas and need deeper water, so one of the main escape behaviors for belugas is to go into shallower water than the killer whales can get into. So if there were killer whales at the mouth of the river when the belugas were eating chums, it is a possibility that the belugas would go up the river to get away from the killer whales and stay up there.”Belugas use sonar to navigate and find food – which often includes copious amounts of fish. Quakenbush says that a dead beluga from Cook Inlet was found with 12 coho salmon weighing close to 100 pounds in its stomach – and that was just one of multiple feedings that a beluga could do in one day.With about a month left before ice starts forming on interior rivers, Quakenbush doesn’t think that the belugas will have much trouble getting back to the ocean – as long as they don’t go too far upriver.“The problem for them could be if the water drops and they stuck above some sandbar or something like that and they can’t get past it and get down. That might be what happened to the beluga that was found near Nenana.”The hunting of beluga whales and other marine mammals is regulated by the National Marine Fisheries Service, under the authority of the Marine Mammal Protection Act. As with the harvest of other marine mammals, beluga hunters must be at least one-quarter Alaska Native. But according to NOAA Fisheries Enforcement Officer Les Cockreham, a beluga that swims upriver is not subject to any additional hunting restrictions.“Basically there is no permit required, there is no season, and they can take as many as they want. However there is one law that we look at very heavily that is in play, and that is a “no waste” issue. In other words, if they kill an animal they have to utilize it.”Cockreham cautions against hunting belugas without prior experience, due to the high risk of losing the animal after striking it.The Yukon River belugas are likely from the Eastern Bering Sea stock, which sustains a healthy population level despite subsistence hunting pressure. The Cook Inlet population of belugas, however, is listed as an endangered species and cannot be hunted.