[5] Millions of migratory waterfowl and shorebirds find food and shelter in the coastal lagoons and freshwater wetlands on their way to and from their subarctic and arctic breeding grounds.

[7] A ruling on March 29, 2019 by the United States District Court for the District of Alaska once again blocked the land transfer,[9] finding that the Trump administration's attempts to remove acreage from the refuge contradicted the existing environmental impact statement and made no attempt to explain why the statement was no longer applicable.

In an unusual action, former President Jimmy Carter filed a statement of support for the motion for the rehearing, saying the swap violated the Alaska National Interest Lands Conservation Act (ANILCA).

[11] Izembek Wilderness hosts a quarter-million migratory birds every fall, including the entire world's population of black brants and thousands of Canada and emperor geese, Steller's eiders, and various species of duck and shorebird.

Raptors which prey on the many species of rodents, birds, and fish in this area include bald and golden eagles, rough-legged hawks, gyrfalcons, and Peale's peregrine falcons.

[12][13] Land mammals that roam this refuge include brown bears, red foxes, wolves, and caribou from the Southern Alaska Peninsula herd.