Black-legged Kittiwakes

Supporting Sound Management of Our Coasts and Seas Seabirds

Pacific Islands 

Ecosystems Research 

Center

Alaska 

Science

Center

Western Ecological 

Research Center

The U.S. Geological Survey (USGS) is the Nation’s 

largest water, earth, and biological science and civilian 

mapping agency. The USGS serves the Nation by 

providing reliable scientific information to describe 

and to understand the Earth; to minimize loss of life 

and property from natural disasters; to manage water, 

biological, energy, and mineral resources; and to 

enhance and to protect our quality of life.

From the cold, high Arctic area of Alaska to the warm, tropical 

Pacific area of Hawai`i, a diverse array of seabird species numbering 

in the millions of individuals live off the bounty of the Pacific 

Ocean. Many come to land only to nest and raise their young—

these are species supremely adapted for life on the water, whether 

it be near the coast or hundreds of miles at sea. Those seabirds that 

reside in the North Pacific year-round are joined each summer by 

millions of migrant birds that leave the southern hemisphere in 

winter for better feeding conditions in the north. Seabirds in the 

Pacific remain one of the great wildlife spectacles on the earth. Yet, 

seabirds face a number of threats such as oil spills, introduction of 

predators to their nesting islands, and conflicts with fisheries. State 

and Federal agencies require increasingly sophisticated information 

on population dynamics, breeding biology, and feeding ecology to 

successfully manage these species and their ecosystems. Within the 

Western Region of the USGS, scientists from the Alaska Science 

Center (ASC), Western Ecological Research Center (WERC), and 

Pacific Islands Ecosystems Research Center are leading the way in 

conducting research on many of these little known species. Their 

aim is to improve our understanding of seabirds in the Pacific and to 

provide information to support informed management of the birds and 

their ecosystems.

U.S. Geological Survey (USGS) 

Western Region: Seabirds

Coastal and Ocean Science

Fact Sheet 2009–3067

July 2009 Printed on recycled paper

Northern Fulmar

Tufted Puffin

U.S. Department of the Interior

U.S. Geological Survey
Populations of seabirds in Alaska are larger and more diverse than seabirds in any similar region of the northern hemisphere. Alaska’s 

extensive estuaries and offshore waters provide breeding, feeding, and migrating habitats for almost 100 million seabirds of 66 

species. Breeding birds number about 50 million individuals of 38 species, which is 96 percent 

of all breeding seabirds in the continental United States. The catalog of known breeding sites 

includes more than 1,300 colonies ranging in size from a few birds to more than 2.5 million.

Seabirds are integral members of marine ecosystems and can serve as sensitive indicators of 

the health and status of these marine ecosystems. Measurements of abundance, demographic 

attributes, diets, behavior, and physiology of seabirds provide accurate real time “sensors” of 

local and large-scale changes in their marine environment.

Forage Fish Ecology

Forage fish species are key food sources for

many marine predators in Alaska marine

waters. The USGS ASC leads an active 

program to better understand how forage

fish distribution, abundance, and composition

affect the population dynamics of marine

birds and mammals. Recently, researchers 

collected and analyzed forage fish data 

from Kenai Fjords and Glacier Bay 

National Parks and the western Aleutian 

Islands in the Alaska Maritime National 

Wildlife Refuge. Hydro-acoustic surveys

of forage fish species were used to identify

prey aggregations in areas important to

marine predators. Using mid-water trawls,

scientists were able to assess prey community 

composition, which is important for 

understanding the food quality available 

to predators. By measuring the associated 

physical and biological oceanographic 

characteristics where food aggregations are 

located, USGS can define marine habitats 

critical to predators such as seabirds to inform 

improved resource management strategies.

Kittlitz’s and Marbled Murrelet Research in 

National Parks and Wildlife Refuges

USGS ASC continues its effort to better understand the status and ecology of the 

Kittlitz’s Murrelet, a candidate species under the Endangered Species Act (ESA) 

and the Marbled Murrelet, presently listed as ‘Threatened’ under the ESA in the 

southern part of its range (Washington, Oregon, and California). USGS ASC, 

in collaboration with the U.S. Fish and Wildlife Service, is studying the nesting 

ecology of the Kittlitz’s Murrelet on Kodiak and Agattu Islands in the Kodiak and 

Alaska Maritime National Wildlife Refuges. As part of a multi-year effort to study 

the breeding ecology and behavior of this species in the refuges, scientists have 

located 21 nests. Automatic cameras record aspects of behavior and biology; eggs 

and chicks are measured and monitored; and nesting habitat is being characterized. 

Monitoring of inland flying behavior and abundance helps assess seasonal patterns 

of attendance and characterize social behavior. USGS scientists also are studying 

Kittlitz’s and Marbled Murrelets in Kenai Fjords National Park where they examine 

seasonal patterns of abundance and gather habitat data to relate 

environmental characteristics to key population factors. Further 

analyses will focus primarily on more refined characterization 

of murrelet habitats and on assessing long-term 

population trends—information essential 

to aiding management agencies in habitat 

conservation planning and to ESA listing 

discussions for both species of murrelet.

Experimental Seabird Colony 

USGS researchers exploit an unusual circumstance on Middleton Island where 

kittiwakes, normally cliff-nesting birds, occupy the sides of a decommissioned 

radar tower on the island. By encouraging and augmenting this behavior using 

artificial ledges, one-way mirror glass, and individual “feeding tubes” at the nest 

sites, researchers conduct what amounts to a long-term, large-scale experiment—

supplemental feeding throughout the breeding season of a sizeable sample of pairs, 

with unfed pairs as controls. The USGS ASC has sustained this endeavor since 1996. 

Presently, about one-half of the study population consists of known-age birds. In the 

future, the entire study population will be individuals with a known history since 

birth. By continuing the protocol of supplemental feeding on Middleton, researchers 

are in effect creating generations of birds that experience contrasting conditions of 

food supply, both during natal development and as breeding adults. This field experimentation is unique in its ability to help 

parse out the effects of food availability, composition, and environmental factors on the population status of seabirds.

Monitoring Breeding, Behavior, and Population Ecology of Seabirds in Alaska

Seabirds in Alaska include 

albatrosses, auklets, cormorants,

fulmars, grebes, gulls, kittiwakes, 

loons, murrelets, murres, petrels, 

phalaropes, and puffins.

Marbled Murrelet
Double-crested Cormorant

Effects of Contaminants on 

Seabirds in San Francisco Bay

The USGS WERC is investigating 

contaminant concentrations and effects 

on several seabirds, including Forster’s 

Terns, Caspian Terns, and Doublecrested Cormorants in the San Francisco 

Bay Estuary. The estuary has a legacy of 

mercury contamination from historical 

mining activities that has resulted in 

elevated mercury concentrations in 

several seabird species. Reproduction is 

the most sensitive endpoint of mercury 

toxicity in birds. As many as 58 percent 

of the Forster’s Terns that breed in the 

South San Francisco Bay are considered 

at high-risk for mercury contamination. 

Scientists have determined that Forster’s Tern eggs that have failed-to-hatch have 

higher mercury concentrations than randomly sampled eggs. Mercury also may be 

impairing chick growth and survival.

Providing Science for Resource Managers to Assess Seabirds and 

Their Habitats Along the Pacific Coast

Species currently studied at the Western 

Ecological Research Center include 

Cassin’s Auklet, Xantus’s Murrelet, 

Marbled Murrelet, Ashy Storm-Petrel, 

Sooty Shearwater, Black-footed Albatross, 

Grey-faced Petrel, Hawai`ian Petrel, 

Northern Fulmar, Forster’s Tern, 

Caspian Tern, California Gull, and 

Double-crested Cormorant.

Forster’s Tern Reproductive Ecology

The USGS WERC studies habitat selection, diet, nest 

success, hatching success, chick growth rates, and survival 

of Forster’s Terns at several colonies in San Francisco Bay. 

Approximately 30 percent of the Pacific Coast breeding 

population of Forster’s Terns nests in the Bay. The population 

has remained stable or has slightly declined over the past 20 years 

and there is concern that the population may be negatively affected by 

current restoration plans to convert several thousand acres of salt ponds, a 

preferred habitat for nesting and foraging, into tidal marsh habitat under the 

South Bay Salt Pond Restoration Project.

California Gulls 

Breeding populations of California Gulls in San Francisco Bay have 

increased 37 fold over the past two decades from less than 1,000 breeding 

birds in 1982 to more than 37,000 in 2007. Their exponential increase 

in the bay may be closely related to their use of landfills and other 

anthropogenic sources of food.

The South Bay Salt Pond Restoration Project plans to restore 16,000 acres 

of salt ponds into tidal marsh and other habitats, and may cause some of 

the 37,000 breeding gulls to move to new nesting sites.

California Gulls are voracious predators and are known to kill the young 

of other coastal birds. Displacement of the largest California Gull breeding 

colony is of concern. It is unknown where these gulls will disperse to breed 

but it is likely that many will nest in nearby breeding populations of other 

nesting waterbirds, including endangered western Snowy Plovers.

Ecology of Vulnerable, Threatened, 

and Endangered Seabirds

Seabird research of the USGS WERC 

is focused on vulnerable, threatened, 

and endangered species so that resource 

managers concerned with island and 

ocean conservation have the best available 

knowledge to assess seabirds and their 

habitats—at sea and on land. Current 

seabird studies use radio- and satellitetelemetry techniques to investigate spatial 

movement and distribution patterns in 

diverse habitats ranging from tidally 

influenced wetlands to remote reaches of 

the World’s oceans.

Research includes at-sea surveys, diet and 

foraging ecology, reproductive success, 

science-based island habitat restoration, 

fisheries conflicts, environmental 

toxicology, and population enumeration.

Forster’s Tern

California Gulls
Seabird Monitoring for Hawai`i and Pacific Islands

Red-Tailed

Tropic Bird

Black Noddy

Sabine’s Gulls

Leading the Way: Developing Pacific Seabird Databases to 

Facilitate Dissemination of Data

The USGS Pacific Islands Ecosystems Research Center develops rigorous methods 

to monitor seabird population status and trends on the National Wildlife Refuges 

of Hawai`i and the Pacific Islands. The objectives are to assess existing data and 

monitoring methods and to provide detailed standardized protocols for 13 species to 

meet seabird management goals. Power analyses and trend assessments have been 

completed on Black Noddy, Red Footed Booby, Red-Tailed Tropic Birds, and 10 other 

Pacific seabird species.

The USGS ASC is leading the way in 

development of two major databases on Pacific 

seabirds. In April 2008, the Pacific Seabird 

Monitoring Database (PSMD) was launched 

on behalf of scores of scientists throughout 

the North Pacific. The PSMD contains vital 

statistics on breeding biology and diet gathered 

on multiple species nesting at colonies scattered 

along the North American coast and across 

the Pacific basin. Another database, the North 

Pacific Pelagic Seabird Database (NPPSD), 

complements the PSMD by collating historical 

data on the distribution and abundance of 

seabirds at sea throughout the Pacific Basin. 

The NPPSD has garnered regional, national, and 

international interest and is being used to assess 

the effects of oil pollution, to model the effects 

of human fisheries and offshore development, 

and to estimate population status and trends.

For more information:

USGS Western Region

Anne E. Kinsinger, Director

909 First Ave. Suite 704, 

Seattle, WA 98104

206-220-4578