Ringed seals are the most abundant and widely distributed seal in the Arctic, and they are also the smallest of the northern ice seals, with adults typically weighing around 50 to 100 kilograms. Named for the pale, ring-shaped markings scattered across their dark gray fur, they are found throughout the circumpolar Arctic as well as in a handful of isolated freshwater lakes and the Baltic Sea. Their life revolves around sea ice to a degree matched by few other marine mammals, which makes them both a keystone species in Arctic food webs and one of the animals most exposed to the consequences of a warming climate.
Where Ringed Seals Live
Ringed seals occupy an enormous range. They are common from the Beaufort and Chukchi Seas off Alaska and Canada, across the Russian Arctic, through the waters around Svalbard and Greenland, and into the Canadian archipelago. Their distribution is highly disjoint, though: beyond the vast Arctic populations, smaller groups persist in the Baltic Sea, Lake Saimaa in Finland, and Lake Ladoga in Russia.1PubMed Central. Complex Origins and History of the Relict Fennoscandian Ringed Seals Those freshwater and brackish-water populations are relics left behind after the last ice age, landlocked when post-glacial land uplift cut off their routes back to the ocean.
Satellite-tracking studies show that Arctic ringed seals tend to stay on the continental shelf for the vast majority of their time. In the Beaufort and Chukchi Seas, tracked seals ranged north of Utqiaġvik, Alaska, during summer and shifted south into the Bering Sea in winter, spending more than 96% of their tracked days over the continental shelf.2PubMed Central. Ringed seal (Pusa hispida) seasonal movements, diving, and haul-out behavior in the Beaufort, Chukchi, and Bering Seas (2011-2017) A small number made brief forays off the shelf edge into the deep Arctic basin during late summer, usually to reach retreating pack ice, where they spent most of their time hauled out rather than diving.
Ice concentration matters. In the northern Barents Sea, ringed seals strongly preferred areas close to the 50% sea-ice concentration boundary. When the distance to that boundary increased by about 120 kilometers, the probability of a seal selecting that area dropped by half. They also favored heavy pack ice in the 80 to 100% concentration range, selecting it roughly 1.4 to 2.2 times more often than open water or lighter ice.3Polar Research. Summer habitat selection by ringed seals (Pusa hispida) in the drifting sea ice of the northern Barents Sea This preference reflects their dependence on ice both as a resting platform and as a habitat where their prey concentrates.
What Ringed Seals Eat
Ringed seals are opportunistic feeders, and their diet shifts with geography, season, and age. In the High Arctic, arctic cod is the dietary staple for adults. Stomach analyses from Greenland covering hundreds of seals showed that in Northwest and East Greenland, polar cod and arctic cod dominated, while in central West Greenland the diet broadened to include amphipods, capelin, redfish, and squid. In the southwest, capelin was the single most important prey item.4NAMMCO Scientific Publications. Diet of the ringed seal (Phoca hispida) in Greenland There were also seasonal swings: in one region, small crustaceans dominated spring diets, snailfish took over from October through January, and then disappeared with the formation of fast ice.
Young seals eat differently from adults. In the North Water Polynya of northern Baffin Bay, immature ringed seals near one site fed heavily on amphipods, while adults at the same location ate mostly arctic cod and polar cod.5Marine Mammal Science. Diet of Ringed Seals (Phoca hispida) on the East and West Sides of the North Water Polynya, Northern Baffin Bay The likely explanation is that juvenile seals are less proficient divers and stick to shallower depths where crustaceans are easier to catch, graduating to fish as they grow. This dietary flexibility is one reason ringed seals have managed to thrive across such a wide range of Arctic habitats.
Most of their foraging dives appear to target the seafloor. Satellite-tagged seals in the Beaufort and Chukchi Seas showed repetitive seafloor diving as the most common activity pattern during their months on the continental shelf.6PubMed Central. Ringed seal (Pusa hispida) seasonal movements, diving, and haul-out behavior in the Beaufort, Chukchi, and Bering Seas (2011-2017) Compared with bearded seals sharing the same waters, ringed seals tend to feed more in the water column (pelagically) and less on the bottom, which gives the two species some ecological separation even when they overlap geographically.7PubMed. Spatiotemporal variation in foraging ecology and mercury concentrations in ringed seals and bearded seals across a latitudinal gradient in the eastern Canadian Arctic
Diving and Physiology
For a relatively small marine mammal, the ringed seal is a capable diver. An average-sized adult, around 74 kilograms and 129 centimeters in standard length, carries an estimated 4.5 liters of available oxygen stores. Based on those stores and the seal’s metabolic rate, the estimated aerobic dive limit is about 9 minutes, meaning that dives shorter than that can be powered entirely by stored oxygen without building up a metabolic oxygen debt.8Canadian Journal of Zoology. Oxygen stores and aerobic dive limit of ringed seals (Phoca hispida) In practice, fewer than 4% of dives by free-living adults exceed that limit, suggesting ringed seals overwhelmingly keep their dives comfortably within aerobic bounds. Their maximum breath-hold capacity has been estimated at about 26 minutes, but such long dives appear to be rare.
Ringed seals maintain breathing holes through thick ice by scratching with the heavy claws on their front flippers. They may keep several holes open throughout the winter, which is essential for survival under fast ice that can be well over a meter thick. This behavior is one of the traits that sets them apart from many other seal species, allowing them to persist in heavily ice-covered waters where other species cannot reliably access air.
Snow Lairs and Pup Rearing
One of the ringed seal’s most distinctive behaviors is the construction of subnivean lairs, small hollowed-out chambers in the snowdrifts that accumulate over breathing holes in the ice. Females give birth to a single pup in these lairs, usually in March or April. The pups are born with a white, woolly coat of lanugo fur and are nursed for about five to seven weeks before weaning.
The snow lairs serve two critical purposes: they provide thermal shelter for newborn pups that are too small to tolerate prolonged exposure to Arctic air temperatures, and they conceal the pups from predators, particularly arctic foxes and polar bears.9Canadian Journal of Zoology. The breeding habitat of the ringed seal (Phoca hispida). The birth lair and associated structures Without adequate snow cover on the ice, pup survival drops sharply. This is one of the reasons ringed seal reproduction is sensitive to changes in snowfall patterns and the timing of spring melt. Years with early rain-on-snow events can collapse lairs prematurely, exposing pups before they are ready to survive on their own.
The Polar Bear Connection
Ringed seals are the primary prey of polar bears across most of the Arctic, and the bond between these two species is one of the tightest predator-prey relationships in any marine ecosystem. Fatty acid analysis of polar bears in the southern Beaufort Sea estimated that ringed seals made up about 46% of their diet, far more than any other prey item. Bearded seals accounted for roughly 20%, seabirds 17%, bowhead whale about 15%, and beluga whale barely 2%.10PubMed Central. Fatty acid-based diet estimates suggest ringed seal remain the main prey of southern Beaufort Sea polar bears despite recent use of onshore food resources
When ringed seal availability declines, polar bears do not simply switch to other food sources with equal success. A study tracking diet quality through chemical markers in polar bear hair found that during periods of low survival, bears were eating diets with lower energy density. Increased consumption of beluga whales and access to bowhead whale carcasses on shore did not compensate for the lost ringed seal calories.11PubMed. Diet energy density estimated from isotopes in predator hair associated with survival, habitat, and population dynamics Because most polar bears in the Beaufort Sea stay with the sea ice year-round, their fortunes are tied tightly to the abundance and accessibility of ringed seals. The fate of ringed seals under climate change, in other words, cascades directly to polar bears.
Spring Haul-Out and the Annual Cycle
In spring and early summer, ringed seals haul out onto the ice surface in large numbers, basking in the sun as they undergo their annual molt. Surveys in Kongsfjorden, Svalbard, found that the number of seals on the ice peaked during the first week of June, with daily highs typically in the early afternoon between about 1:00 and 2:00 p.m.12Marine Mammal Science. Spring Haul-Out Behavior of Ringed Seals (Pusa hispida) in Kongsfjorden, Svalbard Warmer air temperatures and lighter winds brought more seals out. After the early-June peak, haul-out numbers declined as ice began to deteriorate.
Age and sex influenced behavior. Pups hauled out in short, frequent bouts, while adults spent longer continuous stretches on the surface. Adult females showed the most extended haul-out periods, with some staying out for more than 24 hours at a stretch. This spring haul-out period is when most aerial surveys are conducted, because it is the only time a meaningful fraction of the population is visible on the ice rather than hidden beneath it.
Counting Seals From the Air
Estimating how many ringed seals exist is genuinely difficult. They are spread across millions of square kilometers of sea ice, and only a fraction are visible at any given moment. Traditional aerial surveys relied on trained observers scanning the ice from aircraft windows, but infrared camera systems have increasingly replaced human eyes. Comparative trials in the Canadian Arctic found that infrared-based density estimates were roughly two to three times higher than those from visual observers covering the same areas, because the thermal cameras detected seals that human observers missed.13Wildlife Society Bulletin. Comparing infrared imagery to traditional methods for estimating ringed seal density Infrared surveys also eliminate the need for large teams of trained observers and simplify data analysis, making them increasingly standard for ice seal monitoring.14Methods in Ecology and Evolution. Estimating multispecies abundance using automated detection systems: ice-associated seals in the Bering Sea
Even with better detection technology, converting a count of seals visible on the ice into a total population estimate requires corrections for the many seals that are in the water at the time of the survey. Researchers use haul-out behavior data, like the time-of-day and seasonal patterns found in Svalbard, to build correction factors. The global ringed seal population is estimated in the millions, making it one of the most abundant pinnipeds on Earth, but regional population trends are harder to pin down.
The Remarkable Saimaa Ringed Seal
The roughly 420 Saimaa ringed seals living in Lake Saimaa, Finland, represent one of the world’s most endangered seal populations, and their story challenges some long-held assumptions about how these landlocked populations formed. It was traditionally assumed that these seals became trapped in Saimaa about 10,000 years ago as post-glacial land uplift severed the lake’s connection to the sea. The seals did end up in the lake around that time, but genomic work now shows that the Saimaa population diverged from other ringed seals far earlier, forming a separate evolutionary branch at least 60,000 years ago.15PubMed Central. Deep origins, distinct adaptations, and species-level status indicated for a glacial relict seal They were already genetically distinct before they ever arrived in the lake.
That deep divergence is reflected in their anatomy. Saimaa seals have adaptively distinct features in their teeth and tongue compared to Arctic ringed seals, consistent with specialization for the freshwater fish available in their lake environment. Skull morphology has also diverged, likely shaped by a combination of the founding bottleneck, thousands of years of isolation, and dietary specialization.16PubMed Central. Complex Origins and History of the Relict Fennoscandian Ringed Seals Despite extremely low genetic diversity, the population has persisted for nearly 10,000 years, a testament to their resilience. The genetic uniformity appears to stem from an extended founding event and slow erosion over millennia, not from a sudden recent crash.17PubMed Central. Demographic histories and genetic diversities of Fennoscandian marine and landlocked ringed seal subspecies
Lake Ladoga’s ringed seals, by contrast, retained much higher genetic diversity. That population appears to have started with more founding individuals and may have received occasional gene flow from the Baltic Sea, buffering it against the genetic erosion that hit Saimaa so hard.18PubMed Central. Demographic histories and genetic diversities of Fennoscandian marine and landlocked ringed seal subspecies Baltic ringed seals, meanwhile, have mixed evolutionary origins and have maintained remarkably high genetic and morphological diversity. Collectively, the evidence supports classifying the Saimaa, Ladoga, and Baltic populations as distinct taxa.
Bycatch and Conservation in Lake Saimaa
For the Saimaa ringed seal, the single biggest verified cause of death over the past three decades has been incidental bycatch in fishing nets, primarily gillnets set by recreational fishers.19PubMed Central. Effects of fishing restrictions on the recovery of the endangered Saimaa ringed seal (Pusa hispida saimensis) population Juveniles are especially vulnerable, often drowning during their spring dispersal period when they are exploring new areas of the lake and encountering nets for the first time.20Endangered Species Research. Incidental bycatch mortality and fishing restrictions: impacts on juvenile survival in the Endangered Saimaa ringed seal Pusa hispida saimensis
Finland has responded with spatial and seasonal fishing closures, banning gillnets from key areas during the critical spring months. The results have been encouraging: more juveniles now survive to 15 months of age than before the restrictions, and the population grew at an average rate of about 4% per year between 2017 and 2021.21PubMed Central. Effects of fishing restrictions on the recovery of the endangered Saimaa ringed seal (Pusa hispida saimensis) population The situation is not comfortable, though. Estimated bycatch mortality is higher than what is directly observed; for every bycatch that is found, roughly two more go undetected. Observed bycatch alone already exceeds the level biologists consider sustainable for long-term population stability, which means the real toll could be enough to push the population back into decline if restrictions are relaxed.
Contaminants in Ringed Seal Tissue
As top predators in Arctic and sub-Arctic food webs, ringed seals accumulate environmental contaminants in their tissue, particularly mercury and persistent organic pollutants like PCBs and DDT. These chemicals travel to the Arctic from lower latitudes through atmospheric and oceanic transport, and they concentrate as they move up the food chain.
In the Canadian Arctic, contaminant studies have found that young-of-the-year seals, the age class most frequently harvested by Inuit hunters, carry lower levels of cadmium, total mercury, and methylmercury in their muscle and liver than juveniles and adults.22PubMed. Non-essential trace elements, methylmercury, and organic contaminants in hunted ringed seals (Pusa hispida) from Baffin Island, Nunavut, Canada That finding is relevant because it means the seals most commonly eaten by communities have lower contaminant burdens than older animals. In the liver, selenium and mercury were strongly correlated, consistent with the body’s formation of inert selenium-mercury granules that effectively lock mercury away in a less toxic form.
Baltic ringed seals carry a heavier contaminant load than their Arctic relatives. Comparisons have shown clearly higher levels of both PCBs and DDT in Baltic ringed seals and grey seals compared to reference populations from Svalbard and Canada, with PCB levels roughly twice as high as DDT levels in the Baltic animals.23PubMed. Current levels of DDT, PCB and trace elements in the Baltic ringed seals (Phoca hispida baltica) and grey seals (Halichoerus grypus) Decades of industrial discharge into the Baltic left a chemical legacy that persists in the marine food web, and ringed seals, because of their position near the top of that web, reflect it.
Cultural Importance to Indigenous Communities
For Inuit and Iñupiat communities across the Arctic, ringed seals have been central to survival and culture for thousands of years. In Arctic Bay (Ikpiarjuk), Nunavut, hunters surveyed about local wildlife identified the ringed seal as the most important animal used by the community.24Polar Research. Inuit spring hunting techniques and local knowledge of the ringed seal in Arctic Bay (Ikpiarjuk), Nunavut The seal provides meat and fat for food, oil for fuel and light, and skin for clothing and other materials. In Iñupiaq, the ringed seal is called natchiq, and it remains a key species for Indigenous hunters in communities like Utqiaġvik, Alaska.25Arctic Science. Indigenous Knowledge of bearded seal (Erignathus barbatus), ringed seal (Pusa hispida), and spotted seal (Phoca largha) behaviour and habitat use near Utqiaġvik, Alaska, USA
Indigenous Knowledge of ringed seal behavior, seasonal movements, and ice conditions represents an independent and often highly detailed body of ecological understanding that researchers have increasingly sought to integrate with Western science. Hunters can describe behavioral patterns, habitat preferences, and population shifts from decades of observation, offering spatial and temporal resolution that instrument-based studies sometimes lack.
Sharing Space With Other Seals in a Warming Fjord
In Kongsfjorden, Svalbard, ringed seals already share habitat with harbour seals and bearded seals. High-resolution tracking and dive data from all three species revealed that harbour seals overlapped with about 56% of ringed seal core diving areas and nearly 70% of bearded seal core diving areas.26Marine Ecology Progress Series. Spatial overlap among harbour, ringed and bearded seals in Kongsfjorden, Svalbard, during the post-moulting foraging period That sounds like a recipe for competition, but the details tell a more nuanced story. Ringed and bearded seals concentrated their foraging dives near tidal glacier fronts, while harbour seals used shallower, more central areas of the fjord. The species also divided the water column differently: about 62% of ringed seal dives were pelagic, while roughly 70 to 76% of harbour seal and bearded seal dives targeted the bottom.
For now, these species are not in direct competition. But the trajectory matters. Harbour seals are a temperate species expanding northward as Arctic waters warm. If glacier fronts retreat and ice disappears from these fjords, the specialized niches that currently give ringed seals and bearded seals an edge may shrink. The concern is not that harbour seals will outcompete ringed seals in their current habitat so much as that the habitat itself will transform into something that favors the newcomer. It is one more way that climate change reshapes Arctic ecology not through a single dramatic event but through the slow rearrangement of who can live where.