What do narwhal whales eat?

Quick Answer

Narwhal whales eat a relatively specialized diet of Arctic marine prey. Their primary food sources are Arctic cod (Boreogadus saida), Greenland halibut (Reinhardtius hippoglossoides), shrimp, and squid. Unlike many other cetaceans that feed across a variety of ocean depths, narwhals are extreme deep divers, routinely descending 800 to 1,500 meters beneath the surface to hunt. Their diet shifts with the seasons, and they are among only a handful of whale species that spend their entire lives in Arctic waters, making their diet and food habits uniquely adapted to one of the planet’s harshest environments.

What You Need to Know

Primary Prey Species

Narwhals (Monodon monoceros) rely on a small number of key prey species, all of which are found in cold, deep Arctic waters. Studies of narwhal stomach contents have consistently identified four main food items:

• Arctic cod — A small, energy-rich fish that forms enormous schools under sea ice. Arctic cod is a dietary staple for narwhals during the summer months when the fish are more accessible in shallower waters.
• Greenland halibut — A large, deep-dwelling flatfish that becomes critically important to narwhals during winter. Halibut are found at the extreme depths narwhals are capable of reaching.
• Shrimp — Various species of Arctic shrimp supplement the narwhal’s diet, particularly during seasonal transitions.
• Squid — Cephalopods round out the diet and are captured during deep dives.

This relatively narrow diet sets narwhals apart from more generalist feeders like the killer whale, which consumes everything from fish to marine mammals, or the blue whale, which feeds almost exclusively on krill. To learn more about how different species feed, see our guide on what do whales eat.

How Narwhals Hunt

One of the most fascinating aspects of narwhal feeding behavior is how they capture prey. Narwhals lack functional teeth in their mouths — their famous tusk is actually an elongated upper-left canine tooth that projects outward rather than being used for eating. So how do they catch fast-moving fish in pitch-black water?

Scientists believe narwhals use suction feeding, a technique in which they rapidly open their mouths to create a vacuum that pulls prey inside. This method is similar to the feeding strategy used by their close relative, the beluga whale. High-resolution dive data shows narwhals make rapid, targeted movements at depth, suggesting they locate individual prey items rather than filter-feeding through dense swarms.

Narwhals may also use their iconic tusk as a sensory organ. Research published by Smithsonian scientists found that the tusk contains millions of nerve endings capable of detecting changes in water temperature, salinity, and pressure — information that could help narwhals locate prey concentrations in the deep ocean.

Seasonal Feeding Patterns

Narwhal feeding habits change dramatically between summer and winter, driven by the extreme conditions of their Arctic habitat.

Summer (July–September): During the brief Arctic summer, narwhals migrate to shallow coastal fjords and bays in the Canadian Arctic and around Greenland. Here, they feed intensively on Arctic cod and shrimp in relatively shallow waters. This is the primary period of energy accumulation, and narwhals build up thick layers of blubber that will sustain them through the lean winter months. To learn more about where these seasonal movements take them, see where do narwhal whales live.

Winter (November–March): As sea ice expands and daylight disappears, narwhals move to offshore areas of dense pack ice in Baffin Bay and Davis Strait. During this period, they perform their deepest and most frequent dives, targeting Greenland halibut at depths exceeding 1,000 meters. Remarkably, winter may actually be when narwhals consume the majority of their annual food intake. Researchers from the Greenland Institute of Natural Resources found that narwhals make dozens of deep dives per day during winter, spending more time actively foraging than in any other season.

Deep-Diving Abilities

Narwhals are among the deepest-diving marine mammals on Earth. Their ability to reach depths of up to 1,800 meters — well over a mile — gives them access to prey that few other predators can reach. A single deep dive can last 25 minutes or more, during which the narwhal descends into water with near-freezing temperatures and zero sunlight. For context on how cetaceans manage such extreme breath-holding, see how long can whales hold their breath.

This deep-diving capability is essential to their survival. While surface-feeding whales like the humpback whale rely on lunge-feeding techniques in productive upper waters, narwhals have evolved to exploit a deep-water niche with far less competition.

Threats to Narwhal Food Sources

Climate change poses a significant and growing threat to the narwhal’s food supply. As Arctic waters warm, the distribution and abundance of Arctic cod and Greenland halibut are shifting. Reduced sea-ice coverage disrupts the ice-algae ecosystems that Arctic cod depend on, potentially undermining the base of the narwhal’s food web.

Additionally, warming waters are allowing new predators and competitors — including expanding populations of killer whales — to move into narwhal territory. While narwhals are currently classified as Least Concern by the IUCN, their dietary specialization makes them more vulnerable to ecological disruption than generalist feeders. For more on their current status, see are narwhal whales endangered.

Key Takeaways

• Narwhals eat a specialized Arctic diet consisting mainly of Arctic cod, Greenland halibut, shrimp, and squid — a narrower menu than most whale species.
• They are extreme deep divers, hunting at depths of 800–1,500 meters (and sometimes beyond 1,800 meters) in near-total darkness.
• Suction feeding is their primary capture method, as narwhals lack functional teeth in their mouths despite their prominent tusk.
• Diet shifts seasonally — Arctic cod and shrimp dominate in summer, while Greenland halibut becomes the primary prey during the dark Arctic winter.
• Winter may be their most active foraging season, with narwhals making dozens of deep dives daily beneath pack ice.
• Climate change threatens their food web by disrupting Arctic cod populations and ice-dependent ecosystems, making conservation efforts increasingly important for this species.

To learn more about narwhals and how they compare to other cetaceans, explore our narwhal species page or find out is a narwhal a whale.