The Diversity of Chukchi Sea Animals
The Chukchi Sea is home to a diverse group of animals. From top predators like polar bears and walruses to primary producers including ice algae, phytoplankton, and benthic invertebrates.
As the Arctic Ocean continues to warm and thaw, this sensitive ecosystem is at risk for new invasive species. Here’s what we need to know about this potential problem.
The 33 species of seals, which make up the subfamily Pinnipedia, range from least concern to extinct on the IUCN Red List. They are generalist predators, eating a variety of prey species and foraging in both ice-covered and open waters.
When ice melts in the Chukchi Sea, it exposes vast areas of sea floor that are prime habitat for a diversity of benthic-feeding animals. These benthic invertebrates attract large populations of walrus, bearded seals and whales.
These animals often use the Chukchi to breed, denning and foraging. They are impacted by the rapidly changing climate of the Arctic, and its effects on their ice-covered habitats. Using satellite telemetry, we have tracked individual seals in the Chukchi Sea and learned more about their habitat preferences and behavior. This has allowed us to develop predictive models that can identify the locations of seals and help us understand how these creatures may respond to changing environmental conditions. The resulting models will guide how we conduct surveys of ice-associated seals in the future.
The Pacific walrus (Odobenus rosmarus) is an Arctic megafauna that plays a fundamental role in the diet, culture and economy of Alaskan and Russian coastal communities. Their dependence on sea ice for resting and feeding in summer makes them particularly vulnerable to climate change and its associated loss.
Since 2007, walrus numbers in the Chukchi Sea have declined significantly, with many animals unable to reach productive sea floor habitat for foraging in the absence of sea ice. To overcome this challenge, walruses have clustered in coastal haulouts, which require less energy than traveling to the open ocean and provide access to food.
Using satellite imagery and tracking data, we analyzed the behavior of tagged walruses at the Point Lay haulout in both 2018 and 2019. Our results suggest that walruses in United States waters use coastal haulouts in the vicinity of Hanna Shoal in autumn, and leave by 1 of 2 routes: 1) they move west into Russia as summer sea ice nears its minimum; or 2) they stay at the Point Lay haulout until our survey flights are completed.
The lack of sea ice has created conditions that allow marine plants to flourish. Researchers were surprised to discover that phytoplankton grew on the surface of Arctic waters in the Chukchi as well as in open water leads and polynyas.
Birds depend on this flora for food. As a result, the number of bird species in the area has increased significantly. In spring and summer, fish-eating birds like murres, puffins, and kittiwakes nest in the area. They are joined by tundra-nesting shorebirds and sea ducks. The birds use the region to stage for their migrations to and from breeding grounds in Alaska and Russia.
The birds also utilize the shallow, open polynyas that are formed in winter on the sea floor for access to mollusks and other benthic invertebrates. These large biomass accumulations attract benthic-feeding mammals such as walruses and bearded seals. This area is important to King Eiders, which breed along the coast from Point Lay to Barrow and across western Chukotka to Wrangel Island.
The ice edge of the Chukchi Sea provides essential habitat for a variety of marine Arctic organisms, including polar bears, seals and walruses, as well as several species of seabirds and deep-diving fishes. The sea also supports large populations of mollusks and crustaceans. The nutrient-rich waters of the sea are the base of the food chain that supports Arctic wildlife.
Fish species common to Alaska waters, such as salmon, are found in the Chukchi Sea, but they occur in relatively low numbers. This is because the seas are a part of a larger Arctic region, and their population sizes are influenced by what happens in the Bering Sea and upstream coastal areas.
Inland and coastal Chukchi people are traditional fishermen and walrus hunters who depend on the bounty of nature. They believe that all things, living and non-living, have spirits. Their diet includes boiled walrus and seal meat, reindeer blood soup, and a stew made from a semi-digested mixture of bones and brains called “rilkeil.” They also eat frozen fish and edible leaves and roots.