Alaskan Biodiversity

Photo (c) Ben Lowin

Alaska is the most untouched state in the United States. The vast tundra in the interior is home to over 900,000 wild caribou that roam in 32 herds. The rich mosaic of freshwater habitats that connect to saltwater bays and the North Pacific Ocean through thousands of miles of rivers, streams and lakes, are home to many species of wild salmon. There is a strong connection between salmon and the people who consider Alaska their home, for both economic and cultural value. Subsistence living is a large part of the lifestyle in Alaska from hunting and fishing, to gathering.

Photo (c) Dr. Ana Aguilar-Islas

The untamed expanse of wilderness of Alaska covers landscapes of alpine tundra, Arctic tundra, shrublands, boreal forest, coastal rainforest, and ice fields. The third most isolated peak on Earth – after Mount Everest and Aconcagua – is located in the Alaska Range. The Koyukon Athabaskan people who lived at its base called it Denali, which means “the tall one”. It is the tallest mountain in North America at 20,156 feet. The national park in which it resides is also home to some of the most iconic large mammals: grizzly and black bears, wolves, caribou, moose, and Dall’s sheep. 

Southeast Alaska is composed of a submerged mountain range that includes over 1,100 islands that get high amounts of precipitation due to the storm systems emerging from the Gulf of Alaska. This supports the Tongass National Forest, a dense old-growth forest, which covers 80% of the Alaskan panhandle which is 500 miles long. This temperate rainforest is a mixture of towering mountains and granite cliffs that descend into fjords full of salmon, whales and bears. For more than 10,000 years Alaska Natives have lived off this land, able to sustain themselves off the salmon and other wildlife. 

Photo (c) Ben Lowin

To find out more information about marine ecosystems, check out the webpage of the Center for Alaska Coastal Studies.

The part of the Pacific Ocean that is nestled against the southern coast of Alaska is the Gulf of Alaska. The shoreline is made up of mountains, tidewater glaciers and forest. The gulf has a tight link to the coastal ecosystem because many of the plankton that grow in the marine waters rely on nutrients introduced from discharging rivers. Plankton are microscopic organisms that take energy from the sun and turn it into plant biomass that can be a source of food to other animals. The type of plankton that grows in the gulf depends on the season and which nutrients are available. The high productivity of the gulf supports all kinds of animals: killer whales, beluga whales, humpback whales, harbour seals, porpoises and so much more.

Photo (c) Dan Cushing

The northern part of the state touches the Arctic Ocean, the land of both the midnight sun and perpetual night during different times of year, which can affect plants that require sunlight to grow through a process called photosynthesis. However, polar bears, walrus, bowhead whales, spotted seals, gray whales and narwhals can still thrive in this harsh region. The mammals that live here are an important food source for the Inupiat that have lived along this coast since circa 300 B.C.

The active volcanic terrain of Katmai National Preserve is home to thriving salmon stocks. The most vital salmon species in this park is sockeye, as they are the main food source for bald eagles and the world’s largest protected brown bear population. Other mammals in this area are moose, timber wolves, beavers, foxes, sea lions, beluga whales, orcas and gray whales. In 1989, 90% of the coastline was oiled from the grounding of the tanker, Exxon Valdez, in Prince William Sound. This event killed 8,400 birds due to 11 million gallons of crude oil entering the environment. At the time, it was the largest crude oil spill in American waters, and to this day there are still pockets of crude oil that remain along the coast.

Photo (c) Ben Lowin

The most northern national park in the U.S. sits entirely above the Arctic Circle and is slightly larger than the country of Belgium. The Gates of the Arctic National Park and Preserve contains some of the Brooks Range, an uninhabited mountainous region thought to be approximately 126 million years old. The biodiversity of this region must withstand tough conditions. The boreal forest contains black and white spruce mixed with poplar, and the spine of the Brooks Range – an Arctic desert – see huge swings in temperature: it can get to -75F/-59C in winter and up to 90F/32C in summer. It is the northernmost range limit of the Dall’s sheep and a migratory path for half a million caribou twice a year. The caribou are adapted to this harsh climate through growing thich, insulated coats, and having large feet that can dig into the snow to their winter forage plants of lichens, grasses, and small shrubs. These animals are an important food source for the Alaska Natives. 

There are few places as biodiverse as the Aleutian Islands, especially under the harsh conditions found at high latitudes like Alaska. This string of islands that separate the Pacific Ocean and the Bering Sea form the 1,200-mile arc of the Pacific Ring of Fire. This richness in species is due to a convergence of seas, storms and volcanoes that create raging seas with strong winds and 50 foot waves. These disturbances mix up nutrients from the deep ocean attracting many types of invertebrates and fish, which are food to the many seals and sea lions who nest nearby. The passages between the Aleutian Islands are important migration routes for endangered whales such as most of the world’s gray whales. This area also contains large numbers of pollock, halibut, cod, rockfish and crab. 

As Alaska is such a large state, it contains many diverse ecosystems that support completely different wildlife. The flora and fauna, as well as the local population, is intricately connected.

Photo (c) Dan Cushing