Body and limbs
Streamlined bodies with four limbs modified into flippers; limb use differs by family (otariids use front limbs for propulsion, phocids and walruses use hind limbs).
Seal
Seals (pinnipeds) are semiaquatic, fin‑footed marine mammals with streamlined bodies and flippers, adapted for swimming, diving and life in cold waters.
pinnipedearless sealstrue sealseared sealssea lionsfur sealswalrus
Last Updated Mar 9, 2026 · 2 sources
Species Guide
What to know about seals
A clean field guide focused on habitat, identification, behavior, and conservation context without burying the useful parts.
Pinnipeds, commonly called seals, are a diverse clade of carnivorous, fin-footed, semiaquatic mammals that include the families Odobenidae (walrus), Otariidae (eared seals: sea lions and fur seals) and Phocidae (earless or true seals). There are 34 extant species. They have streamlined bodies, four limbs modified into flippers, a layer of blubber for insulation, and fur (except the walrus). Senses are well developed for both air and water, and whiskers (vibrissae) provide an advanced tactile system. Species vary greatly in size and in diving capability. Otariids primarily propel with their front limbs and can use hind limbs as legs on land; phocids and walruses primarily use their hind limbs for propulsion and are more cumbersome on land. Most species spend most of their lives in water but come ashore to mate, give birth, molt, or avoid predators.
Once heavily hunted for meat, blubber and skins, pinnipeds are now protected by international law; some species remain endangered or have gone extinct, and threats include hunting, accidental trapping, pollution, climate change and human conflict.
Otariids primarily propel through water using their front limbs and can pull hind limbs under the body to move on land; phocids and walruses primarily use hind limbs for swimming and are less agile on land.
At the country level, the clearest linked starting points on this guide currently point to Spain for divers looking for seals.
Identification
How to identify seals
The visual markers divers can use underwater, plus the species most likely to cause confusion.
Key identification markers
Ears
Otariids have visible external ears; phocids and walruses lack external ear flaps.
Insulation and skin
Most species have fur and a layer of blubber under the skin; walruses lack fur.
Whiskers
Well-developed vibrissae provide tactile sensing.
Size range
Size varies widely among species, from around 1 m and 45 kg to about 5 m and 3,200 kg.
Common lookalikes
Sea lions vs true seals
Sea lions (otariids) have external ears and walk on land using their hind limbs under the body; true seals (phocids) lack external ears and are more cumbersome on land.
Range and Movement
How seals move through the world
The broad range, seasonal movement, or migratory behavior that shapes where divers encounter this species.
Otariids primarily propel through water using their front limbs and can pull hind limbs under the body to move on land; phocids and walruses primarily use hind limbs for swimming and are less agile on land.
Diet
What seals tend to eat
Useful feeding context that often explains habitat, movement, and encounter style.
Primarily fish and marine invertebrates; some species eat large vertebrates (e.g., leopard seal); walruses specialize on bottom-dwelling mollusks.
Conservation
What is happening with Seals
Status, pressure, and protection context grounded in cited sources rather than filler.
Once heavily hunted for meat, blubber and skins, pinnipeds are now protected by international law; some species remain endangered or have gone extinct, and threats include hunting, accidental trapping, pollution, climate change and human conflict.
Main threats
Hunting and historical exploitation
Commercial hunting for meat, blubber and skins severely reduced some populations; international protections now exist.
Accidental trapping and bycatch
Pinnipeds face risk from accidental trapping and other interactions with fishing gear.
Marine pollution
Pollution in marine environments is a noted threat to pinnipeds.
Climate change
Changing climates affect habitats used for breeding, molting, and foraging.
Human conflict
Conflicts with local people over resources and interactions pose threats to some populations.
Protections and controls
International legal protections
Pinnipeds are now protected by international law following historical commercial hunting.
Traditional uses
Indigenous Arctic peoples have traditionally used pinniped meat, blubber and skin.
Responsible Encounters
How to dive with seals
Conservation-minded guidance for divers who want the encounter without adding pressure.
Give seal space, avoid blocking the animal's path, and follow local site and operator rules for wildlife interactions with other mammals.
Field Notes
Interesting things worth knowing
Useful species context that makes the encounter more meaningful once you are underwater.
Field notes
Monophyletic group
Molecular evidence supports pinnipeds as descended from a single common ancestor.
Closest relatives
Their closest living relatives are musteloids (weasels, raccoons, skunks and red pandas).
Wide size variation
Species range from about 1 m and 45 kg to about 5 m and 3,200 kg.
Diverse vocalizations
Pinnipeds produce various vocalizations, including barks, gong-like calls and complex songs in some species.
Species count
There are 34 extant pinniped species described in the source.
Top Countries
Top countries for seals
The strongest country-level starting points currently linked to this species.
Top Dive Spots
Top dive spots for seals
Directly linked dive spots where this species already shows up in the planning data.
FAQ
Frequently asked questions
Clear planning and conservation answers written for search visibility and AI retrieval.
Research Sources
Seal information sources
Primary and credible references behind the field-guide and conservation claims on this page.
Sources 2Last Updated
Related Species
More in Other Mammals
Related species guides in the same encounter family.
