Baikal Seal

Common Name: Baikal Seal or Nerpa

Class: Mammalia

Order: Pinnipedia

Family: Phocidae

Genus: Phoca

Species: Phoca sibirica

 

Taxonomy/Description

The Baikal seal belongs to the Mammalian Order Pinnipedia, in the family Phocidae.  Other members of Phocidae include elephant seals, gray seals, and monk seals.  Phocids are referred to as true seals.  They are distinguished from other pinnipeds by their inability to support their body using their hind limbs.  The Baikal seal's scientific name, Phoca sibirica, means "seal belonging to Siberia".  This seal is called the "nerpa" by inhabitants of Siberia.  Nerpa means "seal" in Russian.

The Baikal seal is the only freshwater seal species, and is endemic to Lake Baikal of Siberia.  The Baikal seal is a small species of seal.  Adult seals grow to about 4.5 feet in length, and weigh from 110-290lbs.  Males are slightly larger than females.  Baikal seals are silvery gray in color, although some are spotted.  Baikal seals share a variety of morphological characteristics with arctic seals.  Scientists have concluded that Baikal seals are close relatives of the ringed seal.  It is estimated that Baikal seals diverged from ringed seals about 500,000 years ago.  They have larger foreflippers than ringed seals, and two more liters of blood than ringed seals.  The larger quantity of blood allows the seal to dive for longer periods of time.  The Baikal seals' evolutionary relationships to other seals may be clear, but the way they reached Lake Baikal is still a mystery.  Lake Baikal lies hundreds of miles inland from any ocean.  Scientists hypothesize that prehistorically the Arctic Ocean extended farther inland.  Seals were capable of migrating farther into Siberia.

Habitat/Diet

Baikal seals are the only seal species to live entirely in freshwater.  Lake Baikal is a 395 mile long lake in eastern Siberia, bordering Mongolia.  It is the world's oldest lake, dating back 25-30 million years ago, and the world's deepest lake, reaching an estimated depth of 5,315 feet.  Twenty percent of the earth's unfrozen freshwater is held by Lake Baikal. 

A variety of aquatic animals are endemic to Lake Baikal's highly oxygenated water system.  The Baikal seal's diet consists of these endemic fish species.  These include a few species of bullhead, and the golomyanka.  The golomyanka is pearl colored, deep lake fish.  It is extremely rich in Vitamin A, containing a content of about thirty percent.  This fish does not swim in schools, preventing its classification as a food fish.  As a populous fish of Lake Baikal that is not netted by human fishermen, the golomyanka is the staple of the Baikal seal's diet.

Behavior/Reproduction

Baikal seals are solitary animals.  During the winter months while the lake is frozen, seals maintain breathing holes.  As the ice begins to thaw, seals congregate around larger holes to hunt.  Breeding occurs in the water, during late spring.  Females experience a period of delayed implantation.  Gestation lasts nine months.  A single pup is born on the ice in late winter, between February and March.  A newborn pup weighs 7-8lbs at birth and is about three feet in length.  They are covered in a fluffy white natal fur, called lanugo.  This white fur is shed after six weeks, accompanied by the growth of adult fur.  Pups are weaned 2-3 months later.  The weaning is synchronous with the lake ice melting, and since the southern lake melts faster than the northern lake ice, young seals of the southern seal population are smaller at weaning age than northern seal pups.  Male seals reach sexual maturity at 4-7 years.  Females mature sexually at 3-6 years.

Conservation

Baikal seals have been hunted by local inhabitants for thousands of years.  Their meat was once used as a human food source, but is now used to feed livestock.  The pelts of young seals are used to make clothing.  Local governments regulate seal hunting. The bioaccumulation of pollutants in Baikal seals poisons many seals.  Canine distemper outbreaks, contracted from domestic dogs in the area, have occasionally claimed the lives of thousands of seals.  Since seals eat noncommercial fish species, the animals do not compete with human fishermen.  The current population of seals rests at about 80,000 individuals.  Due to the endemism of this species, if special concern is not given to its natural habitat this species could become endangered.

 

Content provided by Canisius College students under the direction of Michael Noonan, PhD.