Newly released studies about one of America's most endangered animals, the Cook Inlet beluga whale, shed new light on the subspecies and could have implications for the Port of Anchorage's modernization project and other development in the region.

The studies — recently peer-reviewed and released last week by a National Marine Fisheries Service journal — indicate that the summer range of the small white whales may have shrunk, causing concern that concentrated groups may be more at risk in a single catastrophic event, such as an oil spill or a collapse in fish runs.

One of the studies, examining construction activity associated with the port's bungled expansion project that was canceled in 2012, found that noise from pile-driving work could have "potential negative impacts" on the whales.

It's possible the construction was not responsible for the apparent behavioral changes witnessed, including less vocalizing "clicks" by the whales during the pile driving, said Leslie Cornick, a co-author of the study on pile driving and dean of Research and Sponsored Programs at Alaska Pacific University.

The authors don't know enough to make a definitive conclusion, she said.

The studies were released as part of a special focus on beluga whales in the journal, Marine Fisheries Review, published by NMFS. They represent a second volume of studies to an earlier group of reports on belugas originally published by the journal in 2015.

The Cook Inlet whales, a roadside attraction for summer tourists and a concern for oil and gas companies and other developers worried about construction limitations in the inlet, are considered by the federal government to be one of the eight species most at risk of extinction in the "near future."

Kim Shelden, a chief scientist for a NMFS beluga aerial survey project, co-authored the study showing that the estimated 340 beluga whales occupying Cook Inlet appear to be increasingly concentrated in prime feeding areas of the uppermost reaches of Cook Inlet, including Turnagain Arm and Knik Arm.

In recent years, nearly the entire population stayed in the area from late spring to early fall, a range that is "markedly" different than what scientists observed in the 1970s, when the whales in mid-summer began spreading to the southern portion of the inlet, the Alaska Fisheries Science Center in Seattle said in a statement released Wednesday.

One theory suggests that because the beluga whale population has steadily declined, they aren't spreading as far to search for salmon, hooligan or other food.

"They can take advantage of staying in that area without competing too much with each other," Shelden said.

The downside is that the greater the concentration of belugas, the more endangered the Cook Inlet population could become during a single catastrophic event, she said.

Another study looks at the risk to the animals posed by such events and other threats, including killer whales, she said.

The studies are the sort of information regulators will likely review as they consider permits for offshore work for the port modernization project that would begin in 2018, said Jim Jager, the port's director of external affairs.

The studies could provide information that contributes to permit limitations, such as preventing certain kinds of activity when belugas are in the area, he said.

"They may say this has nothing to do with what the port is doing, or they may say this is very important. But I'd guess it's all fair game for the permitting process, which is fine and appropriate," he said.