Island Natural Resources

A rich and fascinating array of physical and biological resources make the Pribilof Islands unique. The following links take you to information, maps, photographs, drawings, and video describing and illustrating the natural resources of the Pribilof Islands.

Geology

Basaltic lavas extruding onto a northwest trending structure on the southern Bering Sea Shelf (the Pribilof Ridge) formed the Pribilof Islands (Marlow et al. 1976; Marlow et al. 1994; Winer 2001, 4–7). Though the Bering Sea separates St. George and St. Paul Islands by only forty miles, the geology of the islands is quite different. Volcanic eruptions began on St. George about 2.2 million years ago (Ma), continuing intermittently until about 1.6 Ma (Cox et al. 1966). Following a hiatus of more than 1 million years, eruptions began building St. Paul Island, and possibly volcanism on the island has not yet ended (Cox et al. 1966).

Thirteen thousand radiocarbon years before present, the Pribilof Islands were uplands on a large island lying among dozens of small islands (Guthrie 2004). Over the next several thousands of years, Bering Sea inundation claimed land, gradually decreasing the size of the Pribilof Islands. St. Paul Island reached its present size some time after 5,000 years before present.

Photo of cludy blue sky over green grass landscape.
St. Paul Island's landscape (NOAA).

St. Paul Island is the youngest eruptive center in the Bering Sea basalt province, the last eruption occurring approximately 3,200 years ago at Fox Hill (Winer 2001, 19). The island has never been glaciated (Hopkins and Einarsson 1966). Its surface consists of more than fifteen scoria and spatter cones ranging from thirty to one hundred meters above their bases, surrounded by small shields of coalescing low viscosity lava flows (Winer 2001, 20). Headlands, sandy beaches, and wave-eroded cliffs comprise St. Paul Island’s shoreline.

Photo of green grass bluffs.
St. George Island's High Bluffs (NOAA).

Cinder cones are absent on St. George Island. The island is an undulating highland with evidence of glacial erosion and deposition (Hopkins and Einarsson 1966). High Bluffs, the culmination of a narrow ridge extending along the western part of St. George Island’s north coast, is perhaps the most prominent topographic feature on the island. St. George Island has a few perennial streams (Hopkins and Einarsson 1966), in contrast to St. Paul Island which has no surface streams. The volcanic rocks of the Pribilof Islands are highly permeable; thus, most precipitation infiltrates and little runs off (Hopkins and Einarsson 1966).

Flora

Photo of purple flower.
Top-down view of a lupine (NOAA).

Inland on both St. George and St. Paul Islands, rocky tundra supports vegetation dominated by various grasses and sedges characteristic of subarctic tundra (Veltre and Veltre 1981). Flowering plants such as lupines, lousewarts, and monkshood bloom in summer, and a few varieties of berries including crowberry (Empetrum nigrum) and cloudberry (Rubus chamaemorus) are found. The tundra appears treeless; however, dwarf species, such as dwarf willow (Salix sp.), may grow to a few inches in height. James Macoun (1899) and George Haley (circa 1920 and 1925) provided some of the first detailed descriptions of the islands’ terrestrial plant life. The U.S. Department of Agriculture, Natural Resources Conservation Service, recently produced maps of St. Paul Island’s vegetative communities (U.S. Department of Agriculture undated, circa 2001, 23).

William Setchell (1899), under the auspices of the U.S. Commission on Fur Seals and the Fur-Seal Islands, provided the most complete summary of Pribilof Islands marine algal flora prior to 1979. Setchell’s summary included descriptions of four green algae, ten brown algae, and twenty-one red algae. During the 1970s, as the eastern Bering Sea was considered for oil and gas development, the need for baseline data prompted studies of intertidal and subtidal algae about the Pribilof Islands. Algae identified from subtidal collections made at St. George, St. Paul, and Otter Islands and one intertidal collection made at Zapadni Bay on St. George included five green algae, twelve brown algae, and thirty-eight red algae species (Calvin 1979). Thirty of the species were new records for the Bering Sea. O’Clair et al. (1979) investigated intertidal algae community composition and species distribution and abundance at seven Pribilof Islands’ sites. They concluded that species diversity is low where the frequency of sea ice scouring is high and that the relationship is likely causative. Species richness of most major taxa was significantly lower in the Pribilof Islands than at Amak and Akun Islands where ice had not recently scoured the shores.

Legend information for USDA soil survey map
(Microsoft Excel file)

Marine Mammals

Photo of seal.
A female northern fur seal on St. Paul Island (NOAA)

The Pribilof Islands and their surrounding sea support a diversity of marine fauna. Best known may be the islands’ northern fur-seal (Callorhinus ursinus) population, constituting just over 50% of the world’s population (Ream 2007, pers. comm.). The National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service, estimated the 2004 total northern fur-seal stock size for the Pribilof Islands to be 756,000 (Ream 2007, pers. comm., derived from pup production estimates of Towell et al. 2006). This is a decrease from the 2002 total northern fur-seal stock size estimate of 848,000 (York et al. 2005). The estimated number of pups born on the islands has also shown a decline. Towell et al. (2006) estimated the number of pups born on St. Paul in 2004 was 15.7% less than in 2002 and 22.6% less than in 2000. For St. George Island, the estimated number of pups born in 2004 was 4.1% less than in 2002 and 16.3% less than in 2000. Estimated pup production has declined to the 1918 level on St. Paul Island and below the 1916 level on St. George Island, years in which the northern fur-seal population was recovering from the devastation wrought by pelagic harvests.

The immensity of the seal herd once entranced Henry Wood Elliott, an assistant agent for the U.S. Department of Treasury. Elliott studied the fur seals and the natural history of the Pribilof Islands as an avocation. By the time he concluded his studies in 1876 with the controversial publication The Seal-Islands of Alaska (Elliott 1976), he’d risen to unexpected acclaim as a fur-seal expert. Elliott took copious field notes, painted watercolors, conducted a census of the seals, and mapped the islands’ rookeries and haul outs. Joseph Stanley-Brown, a special treasury agent for the U.S. Geological Survey in 1891, George A. Clark in 1913, and Charles H. Townsend, a naturalist on the U.S. Fish Commission steamer Albatross, also mapped the fur-seal rookeries and haul outs on St. Paul and St. George Islands, respectively, in the late nineteenth century.

Photo of orca.
An orca whale near St. Paul Island (NOAA)

Numerous other marine mammals occur in the Pribilof Islands’ region, many being near the northern or southern limits of their ranges (Haley 1986; Hanna 1923; Preble and McAtee 1923, 105–107). Species near their southern limits are the ringed seal (Phoca hispida), bearded seal (Erignathus barbatus), walrus (Odobenus rosmarus divergens), and bowhead whale (Balaena mysticetus). Species near their northern limits are the Pacific harbor seal (Phoca vitulina richardii), Steller sea lion (Eumetopias jubatus), Dall’s porpoise (Phocoenoides dalli), northern giant bottlenose or Baird’s beaked whale (Berardius bairdii), sperm whale (Physeter macrocephalus), and right whale (Eubalaena glacialis). The killer whale (Orcinus orca) occurs both north and south of the Pribilofs, and may be seen feeding on fur seals. Also, occasionally observed near the Pribilofs are the humpback whale (Megaptera novaeangliae), fin whale (Balaenoptera physalus), minke whale (B. acutorostrata), spotted seal (Phoca largha), ribbon seal (Phoca fasciata), and harbor porpoise (Phocoena phocoena).

The Pribilof Islands once served as home, breeding grounds, or shelter for thousands of Steller sea lions and sea otters (Enhydra lutris), and unknown numbers of walrus and harbor seals27 (Preble and McAtee 1923, 105–107). K. T. Khlebnikov’s notes from the early 1800s indicated, “At the time the island was discovered… there were many sea otters. At present they never appear, but fur seals and sea lions usually come. Walrus seldom come to these islands.”28 Elliott (1976, 93) reported that sea lions were “common,” and walrus and harbor seals were “a few only” in the late 1800s.

Osgood et al. (1915, 119–120 ) wrote, “Until comparatively recent times sea lions were found in thousands on both St. Paul and St. George Islands…Where formerly there were many thousands of the huge creatures there are at present only a few hundred on both islands.” Reports from early American occupation indicated sea lions on the Pribilofs numbered 20,000 to 25,000 at St. Paul Island and 7,000 to 8,000 at St. George Island with a few breeding at Walrus Island (Preble and McAtee 1923, 107, citing Elliott 1875, 153). Northeast Point was the major sea-lion rookery on St. Paul Island (Preble and McAtee 1923, 107; and, Osgood et al. 1915, 120). According to various authors, at least three sea-lion rookeries existed at St. George Island, presumably at Sea Lion Point (near Garden Cove), East Rookery and Tolstoi Point.  A sea-lion rookery may have existed at Sea Lion Rock (Preble and McAtee 1923, 107; Osgood et al. 1915, 120; and, Hanna 2008, 180). “But they [sea lions] were subjected to indiscriminate slaughter on the islands from 1867 to 1914 when the first steps were taken to prevent the total extermination of this very interesting species from the group. In 1916, a few more than 400 animals of all classes, males, females, and young were counted at the height of their breeding season, and in 1922, it was estimated that there were about one thousand.” (Hanna 2008, 181) During at least the mid-twentieth century and into the first decade of the twenty-first century, a rookery existed at Walrus Island. The Pribilof Islands represent the northern most occurrences of Steller sea-lion rookeries in the eastern Bering Sea (AFSC 1996).

Sea otters, abundant at the time of Russian discovery of the Pribilof Islands in 1786, were nearly exterminated from the Pribilof Islands by the early to mid-nineteenth century. Purportedly, as many as 5,000 sea otters were taken from St. Paul Island during the first year of its human settlement (Preble and McAtee 1923, 105 –106). “A dead one was picked up on the beach of St. Paul in 1895 and another on St. George somewhat later.” (Hanna, 2008, 181) NOAA filmed a single sea otter feeding in the nearshore waters of St. George Island during 2004.

At the time of Russian occupation of the Pribilof Islands, walrus are believed to have been present in sufficient numbers to allow the taking of many each year. St. George, St. Paul, and Walrus Islands appear to have been walrus haul outs. According to a very old man, Eoff Philemonoff, interviewed during 1899 at St. George, many walrus lined the beach between Sea Lion Point and Tolstoi Point.29 Observations of walrus remains found on the islands have been overwhelmingly of male walrus, therefore no indication exists that walrus breed on these islands (Elliott 1976, 93, 97; Hanna 1923; Preble and McAtee 1923, 106). Human inhabitation of St. George and St. Paul Islands is credited with the disappearance of walrus from these islands. The last report of a significant walrus haul out on the Pribilof Islands was Elliott’s 1872 observation of at least 150 males on Walrus Island (Elliott 1976, 94). Preble and McAtee (1923, 107) summarized walrus sightings at the Pribilof Islands up through 1918. Walrus continue to occasionally appear on the islands, although more typically as weakened or dead animals. Two dead walruses were found in January 2006 on St. George beaches, one near Tolstoi Point and the other near East Rookery (Andrew Malavansky 2006, pers. comm.). These occurrences perhaps corresponded with the pack ice, including a raft of ice approximately one mile by two miles that approached within two miles of St. George Island. Bones still commonly appear in the dunes and beaches about Northeast Point on St. Paul.

Click here to view videos about marine mammals in the Video Gallery

Observations of Marine Mammals on the Pribilof Islands in the Early Twentieth Century

“Of the whalebone whales, the bowhead, right whale, and sulphur bottom may be noted. A sperm whale floated ashore on St. George Island in 1914 and another on St. Paul Island in 1919.”

“An old log record indicates that one [bearded seal] was obtained many years ago by the natives of St. George Island, but no specimen was ever saved until 1917–18 when Mr. C. E. Crompton obtained the skin and skull of one on the same island and forwarded them to the U.S. Museum.”

The presence of several bearded seals on a St. George Island beach in 1900 was postulated to be associated with ice pack about the island that year.

“In 1915, a harbor porpoise was found at Northeast Point, St. Paul Island and the following winter a school of 13 was forced on shore on St. George Island by drift ice.”

“One of these beautiful animals [ribbon seal] was taken 84 miles west of St. Paul Island in 1896; a native of St. George, George Merculief, shot one from shore in 1900 and another was seen at the Myak of that island, hauled up with the other hair seals, during the winter of 1916.”

“Two small rookeries of these animals [hair seals, Phoca richardii pribilofensis] are found on St. George Island; one is located on the south side of the island under Red Bluffs, near Cascade Point; and the other is near the Myak, a high steeple rock near the northwest end of the island. Both are in places absolutely inaccessible from the land side and it is seldom indeed that a boat is able to visit these inhospitable, rock bound shores. There are also two rookeries on St. Paul Island; one is on the north shore where the ancient Russian village of Marunich was located…The other rookery is at the Southwest Point of the island where, likewise offshore rocks are occupied.”30

Land Mammals

Only three species of land mammals are considered native to the Pribilof Islands: arctic fox (Alopex pribilofensis), shrew (Sorex pribilofensis), and lemming (Lemmus nigripes) (Preble and McAtee 1923, 102–105, 112). The shrew is found only on St. Paul, and the lemming is found only on St. George. Other land mammals have been introduced or, in the case of the polar bear, visit occasionally. Rats, muskrat, squirrel, and jack rabbits having had the opportunity for introduction did not retain a grip on the islands. Lemmings were unsuccessfully introduced for a third time at St. Paul Island in 1925. The lemmings were released at Lake Hill (Bower 1926, 143).

Arctic Fox

Photo of white fox.
A white arctic fox (NOAA).

The arctic fox is found on both St. George and St. Paul Islands. Edward Preble and W. L. McAtee (1923) assumed that drift ice originally brought the arctic fox to the islands, where the fox became slightly differentiated from foxes of the mainland. G Dallas Hanna (2008, Chapter IX) wrote about foxes and the fox industry on the Pribilofs:

Normally the species is a beautiful snowy white in winter and on account of its abundance and wide range it does not command a high price on the market. But on these and a few other islands, a melanistic strain predominates and the slate colored pelts are called “blue” in the fur markets. Because of their relative scarcity they command a much higher price than the white. On St. George Island, through selective breeding, the white strain has been almost entirely eliminated, but on St. Paul it still runs about 25 per cent of the total catch. It would be a comparatively easy matter for the animals to reach the islands in winter over the drift ice since they would have but 200 miles to travel in a straight line. They are given to such wanderings and have been observed several miles away from land on the ice floes. And Otter Island seems to have been so stocked from St. Paul Island, many times in the past.

The blue fox is the chief enemy of the breeding birds. This little animal almost defies the laws of gravitation in its scaling of the perpendicular cliffs for bird eggs. The animals jump from ledge to ledge on dizzy heights with a sheer drop of a hundred or a thousand feet below them, many times with an unbroken egg in the mouth.

Lemming

While the lemming is found only on St. George Island, purportedly their introduction on St. Paul Island was attempted three times, though none were known to survive. Historically, the St. George Island lemming population fluctuated, being abundant at times and scarce at other times (Osgood et al. 1915, 131; Preble and McAtee 1923, 112).

Shrew

Preble, Hanna, and A. G. Whitney collected early shrew specimens on St. Paul Island, taken primarily from a partially marshy tract bordering a shallow pond between the village and East Landing, but also from Northeast Point (Preble and McAtee 1923, 102). From time to time, shrews may be found in households.

Polar Bear

The polar bear (Ursus maritimus) is a rare visitor to the Pribilof Islands. In the late 1800s and early 1900s, polar bear arrived in conjunction with the ice pack (Preble and McAtee 1923, 103; Ray 1971). They were last recorded on St. George Island in 1915: “These men report seeing bear tracks near the Company House at Zapadni…They lead from the sea line to a place where the animal had apparently laid down and again to where it again took to the water.”31

Reindeer

Photo of reideer on hill.
A herd of reindeer on the Pribilof Islands (NOAA).

James Judge and Dr. Warren Evermann of the Bureau of Fisheries, with the cooperation of the Bureau of Education and the Revenue Cutter Service, introduced twenty-five reindeer (Rangifer tarandus) on St. Paul Island and fifteen on St. George Island in 1911 (Hanna 2008, 196). By 1921, there were 250 reindeer on St. Paul Island and 160 reindeer on St. George Island (Preble and McAtee 1923, 115), and by 1938, there were about 2,000 reindeer on St. Paul Island (Thompson 1954). Poaching, harsh winter weather and starvation due to overgrazing of the tundra caused the St. Paul herd to become severely depleted in the 1940s (Scheffer 1951, 356–362; Olson 1951, Thompson 1954). In 1950, only eight reindeer remained at St. Paul Island. Then in 1951, thirty-one reindeer were brought to the island from Nunivak Island (Thompson 1954). The herd died out at St. George by 1953. Several attempts to restock St. George failed until 1980 when at least ten reindeer imported from Umnak Island led to several fawns in 1981. In 2007, several hundred reindeer roam St. Paul and St. George Islands. The reindeer are hunted by permit. The U.S. Department of Agriculture, Natural Resource Conservation Service, with federal, state, and local assistance, has developed a plan for reindeer management on St. Paul Island (USDA undated, ca. 2001).

House Mouse

Mice were brought to the islands by ships during Russian occupancy (Hanna 2008, 202). Kiril Timofeevich Khlebnikov’s notes stated the mice [he was likely referring to the lemming] were “A small, tailless variety (Pierce 1994, 277). Fur yellowish brown.” Frederick W. True (1899, 345–354) noted that the house mouse was extremely abundant about the City of Saint Paul and had been observed on St. George Island. Today, the house mouse may be found on St. Paul but not St. George.

House mice were introduced on St. Paul before the purchase of the islands in 1867, and in the wild state they have spread from the habitations into the meadows and tundras [sic]. Some of them are white, others have white spots, but the great majority of them are indistinguishable from the well-known household pest of more southern climates. The cats appear to be of absolutely no value in reducing the numbers of the mice. In some inexplicable manner the little rodents have never become established on St. George Island. (Hanna 2008, 201)

Rat

An animal that has not made a home on the Pribilof Islands—the rat—is worthy of special note. Rat introduction would threaten bird and shrew populations and could transfer diseases to humans and wildlife (Sowls and Byrd 2004). Until the early 1990s, the lack of harbors on St. Paul and St. George Islands helped keep the islands free of rats. With the construction of harbors, island entities, government agencies, and industry began a program designed to impede rat introduction. The program consists of trap and poison stations, outreach and education, local shipwreck response capabilities, and regulations (Sowls and Byrd 2004; Sowls et al. 2004). Over a million trap nights have passed and six rats have been killed on the St. Paul docks; yet there is no evidence of rats becoming established anywhere in the Pribilof Islands (Sowls and Byrd 2004).

Jack Rabbit, Squirrel, and Muskrat

During its lease of the Pribilof Islands (1890–1910), the North American Commercial Company attempted an introduction of jack rabbits (Hanna 2008, 194). Its efforts focused on a desire to provide food for blue foxes during the winter season. The same rationale led to attempts to introduce ground squirrels in 1899 and 1913, and presumably muskrat in 1913 (Osgood et al. 1915, 129; Preble and McAtee 1923, 113). The first squirrel introduction occurred near the City of Saint Paul, and the subsequent disappearance of the animal was attributed to cats, though possibly foxes played a hand. The second squirrel introduction involved the release of five animals near the City of Saint George. Two were known to survive the winter but were not seen again. A single muskrat, the only one of seven shipped not to become the prey of its own species during transit, was released in a pond near the City of Saint George; it did not survive (Preble and McAtee 1923, 113). Preble commented on such introductions in 1914: “The abnormally crowded condition of the fox life on the Pribilofs has a sinister bearing on the practicability of adding to their food resources by introducing small mammals among them.”(Preble et al. 1916, 129)

Domestic Animals

Horses, mules, cattle, poultry, swine, sheep, and cats have lived on the Pribilofs, though only cats remain today (Osgood et al. 1915, 128). The domestic cat came to the islands as a friend of man.

Cats have become acclimated on St. Paul Island only. There they run wild in the village and many of them are a nuisance in the same way as we find them elsewhere. Through some fortunate circumstance they have failed to get a start on St. George although individuals have been taken there from time to time.

In 1916, Mr. and Mrs. George Haley went to St. Paul Island to teach the local school and they took with them a female cat descended from stock from the Isle of Man [Manx cat]. Thus, a new strain was introduced into the local breed and the final development may be watched with considerable interest by students of heredity. (Hanna, 2008, 201)

Photo of two men with a large ox.
St. George Agent with large oxen (NARA).

Horses and mules were used for many years on St. Paul Island to haul supplies and provide transportation to distant rookeries (Osgood et al. 1915, 127). On both St. Paul and St. George Islands, cattle furnished milk and occasionally beef for government employees. Horses, mules, and cattle found pasturage during about half of the year and were fed imported food for the remainder of the year.

Government employees and Natives on both islands kept poultry to supply them with eggs. Productivity decreased during the colder season, leading many Natives to house poultry in their attics. Osgood et al. (1915, 128) recommended considering the establishment of a large poultry house to be used by the community.

Natives on both islands raised swine (Osgood et al. 1915, 128). During the summer, the swine subsisted on plants from the village and nearby fields. Seal killing fields also provided subsistence for the swine.

Birds

The Pribilof Islands are also known for their bird populations. A special 10th anniversary issue of WildBird listed the Pribilof Islands as one of the top ten birding locations in North America (Konrad 1996). Kent Sundseth (K. Sundseth 2005, pers. comm.), a refuge operations specialist for the U.S. Fish and Wildlife Service, Alaska Maritime National Wildlife Refuge, provided the following information, which elucidates the reasons for such recognition.

An estimated 2.7 million seabirds migrate to the Pribilofs each summer to hatch and raise their young. About 2.5 million use St. George Island, which has eight times more cliff area than St. Paul Island. Well over 200 species of birds have been recorded in the Pribilof Islands, though more exact figures vary. Thirteen species of seabirds are known to nest in the Pribilofs (See table below). The most numerous include: thick-billed murre (Uria lomvia), common murre (Uria aalge), red-legged kittiwake (Rissa brevirostris), black-legged kittiwake (Rissa tridactyla), least auklet (Aethia pusilla) (known locally as the “choochkie”), crested auklet (Aethia cristatella), parakeet auklet (Aethia psittacula), tufted puffin (Fratercula cirrhata), horned puffin (Fratercula corniculata), red-faced cormorant (Phalacrocorax urile), and northern fulmar (Fulmarus glacialis). Other seabird species recorded in small numbers, but not necessarily breeding on the islands every year are the pelagic cormorant (Phalacrocorax pelagicus) and glaucous-winged gull (Larus glaucescens). St. George Island’s murre colony is the largest in Alaska with 1.5 million thick-billed murres. The U.S. Fish and Wildlife Service estimated that 80 percent of the world’s red-legged kittiwake population nests on St. George Island. The winter wren (Troglodytes troglodytes), snow bunting (Plectrophenax nivalis), and gray-crowned rosy finch (Leucosticte tephrocotis) are three species of passerine birds (or songbirds) that nest in the Pribilof Islands and are year-round residents. The Lapland longspur (Calcarius lapponicus) migrates to the islands to nest each summer. A unique subspecies of shorebird, the Pribilof rock sandpiper (Calidris ptilocnemis ptilocnemis), also nests on the islands. Common ravens (Corvus corax) are suspected of nesting on St. George Island in recent times, though this has not been documented. (Kent Sundseth, USFWS, 2005)

Number of Adult Breeding Seabirds Observed on the Pribilof Islands, Alaska

Species

St. George Island

St. Paul Island

Otter Island

Walrus Island

 Northern Fulmar (Fulmaris glacialis)

 53,980

1,500

83

 

 Red-faced Cormorant (Phalacrocorax urile)

5,000

2,500

40

42

 Glaucous-winged Gull (Larus glaucescens)

 1*

1*

 

 

 Black-legged Kittiwake (Rissa tridactyla)

62,568

18,140

2,096

100

Red-legged Kittiwake (Rissa brevirostris)

193,930

1,175

338

 

Common Murre (Uria aalge)

201,913

14,243

1*

 1,021

Thick-billed Murre (Uria lomvia)

1,098,600

76,065

1*

 50

Unidentified Murre (Uria spp.)

 

 

12,800

 

Parakeet Auklet (Aethia psittacula)

150,000

34,000

1*

20

Least Auklet (Aethia pusilla)

250,000

23,000

1*

300

Crested Auklet (Aethia cristatella)

28,000

6,000

1*

1*

Tufted Puffin (Fratercula cirrhata)

6,000

1,000

1*

 

Horned Puffin (Fratercula corniculata)

28,000

4,400

1*

2

Total Cormorant (all cormorant species combined)

5,000

2,500

40

42

Total Murre (all murre species combined)

1,300,513

90,308

12,800

1,071

Total of all species combined

2,077,991

182,023

15,357

1,535

*Species was spotted at this location but is rare and uncounted.
Source: U.S. Fish and Wildlife Service Beringian Seabird Colony Catalog (2005). The USFWS frequently updates the catalog. The source and year of the data in the table may vary.
red-legged kittiwakes perched on cliffs
Red-legged kittiwakes on St. George Island (NOAA).

St. George and St. Paul Islands are two of nine annual ecological monitoring sites in the Alaska Maritime National Wildlife Refuge. Bird counts from 1976 to 2002 indicate red-legged kittiwakes and thick-billed murres on St. George Island experienced significant declines during the late 1970s and 1980s followed by modest but steady increases from the mid 1990s to the present (Renner and Howard 2003; Thomson 2005). On St. Paul Island, red-legged and black-legged kittiwakes experienced declines from 1976 through the late 1990s (Renner and Howard 2003). Common murres and thick-billed murres declined from 1976, possibly leveling or increasing after 2000. The reason for the seabird declines is not entirely clear, but scientific studies suggest it is linked to prey availability and quality (Hunt and Byrd 1999; Kitaysky et al. 2005).

Click here to view a video of seabirds on St. George Island

Click here to view a video of seabird research activities

Close-up view of two horned puffins
Horned puffins on St. George Island (NOAA).

A saltwater lagoon, known as the Salt Lagoon, on St. Paul Island, is an important and unique component of the Pribilof ecosystem. The Salt Lagoon is the only shallow, tidal-driven habitat in the Pribilof Islands, with substantial tide flats exposed during low water. The tide flats serve as foraging areas for shorebirds such as the Pribilof rock sandpiper and ruddy turnstones (Arenaria interpres) (Flint et al. 1999, 1). The lagoon’s location near the edge of the eastern continental shelf and about 300 miles from the continental shore of Alaska makes it important habitat for migratory waterfowl.

Kiril Timofeevich Khlebnikov (Pierce 1994, 274–277) and William Palmer (1899) provide early and late nineteenth-century accounts of Pribilof birds, respectively. Khlebnikov described fifteen types of birds. Palmer provided a list of sixty-nine bird species observed on the Pribilof Islands.

Marine Invertebrates

Intertidal and nearshore subtidal benthic invertebrates around the Pribilofs have received little intense study, though most forms are expected to occur widely around the Bering Sea. William H. Dall (1899, 539–546) summarized the knowledge of molluscan fauna in 1899. He credits Russian naturalist Elia Wossnessenski with making the first collection of mollusks on St. Paul Island circa 1850. Dall identified sixty-six species on St. Paul Island and forty-two species on St. George Island. Included on his list is the nektonic giant squid; he wrote, “I have heard that specimens have been cast ashore on St. Paul, though no naturalist has seen them.” Dall (1899, 539–546) also noted the brachiopod Rhynchonella (Hemithyris) psittacea was “abundant at times on St. Paul beaches,” and he described a tunicate, Boltenia beringi, from St. George Island. William Emerson Ritter (1899) provided a more detailed description of the tunicates of the Pribilof Islands, though he did not list Boltenia beringi. Mary J. Rathbun (1899, 555–557) provided a list of Crustacea occurring on and near the Pribilof Islands.

More recently, Russian scientists conducted a detailed study of the St. Paul Island Salt Lagoon (Flint et al. 1999). They found eighty species of benthic organisms from ten higher taxa in samples collected from the lagoon, harbor, and the connecting channel. Amphipod and polychaete species were dominant taxa. Species richness was the highest in the harbor, with thirty-three species collected at one sampling station. The highest biomass (81 grams per square meter) was found at a Salt Lagoon sampling station.

Insects and Arachnids

Several surveys of insects and arachnids on the Pribilof Islands were conducted in the late 1800s and early 1900s. W. L. McAtee (Preble and McAtee 1923) offers the most recent and comprehensive documentation of these surveys. His compilation of data reported 276 species of insects, arachnids, and chilopods on the Pribilof Islands. Specimens were collected from outdoor habitats as well as people, seals, and birds. McAtee recognized the role of ships from the south in introducing some species to the islands.

Fossils

Prehistoric mammoth remains have been found on St. Paul and St. George Islands (Preble and McAtee 1923, 119; Ray 1971). Research indicates mammoths survived on St. Paul Island about 2,000 to 3,000 years after their extinction in other parts of North America (Crossen et al. 2005; Guthrie 2004). Crossen et al. (2005, 463) and Guthrie (2004) attribute the mammoth’s extended survival on St. Paul Island to the island’s isolation and late discovery by humans. Mammoths survived on St. Paul Island as long as the land area provided for adequate forage and the population remained sufficiently large to prevent inbreeding (Guthrie 2004). Mammoth tusks are sometimes found on the beaches, such as North Beach (Preble and McAtee 1923, 119–120), and anecdotal reports indicated that one or more tusks were found in dredged spoils from St. Paul’s Village Cove. Mammoth teeth and bones have also been recovered from several lava tubes.

Dall (1899, 539–546) and others (Stanley-Brown 1892, 496; Dawson 1895; Hanna 2008, 235–241) discussed finds of marine fossils on St. Paul Island. On St. Paul Island, marine fossils were reported in sedimentary rock outcrops at Ardiguen Rookery on Reef Point, portions of Village Hill, and Tolstoi Point. In 1847 and 1848, Russian naturalist Elia Wossnessenski of the Russian Imperial Academy of Sciences, St. Petersburg recognized marine fossils in sedimentary rocks at Black Bluffs. Within fifty years, these exposed beds disappeared due to strong erosional forces. The fossil beds are known to remain subtidally, however, and the fortunate collector may still find examples cast up on the beach. Fossils imbedded in sedimentary rocks apparently became detached from the seabed during the volcanic eruption(s) that formed Black Bluffs (Dall 1899, 539–546). On St. George, fossil mollusks, fish bones, and diatoms were reported at Tolstoi Point. Fossil diatoms were also reported at Garden Cove. Sedimentary rocks were said to outcrop at Cascade Point, Big Cliffs, Staraya Artel Rookery, Dalnoi Point, and Zapadni, but they were not closely examined for fossils. Sedimentary rock was also reported on the west side of Otter Island.