Surf Scoter (Melanitta perspicillata) by Rinus Baak USFWS.jpg

World - Diving into the Mysterious World of Sea Ducks

Plunging into the icy waters of North America's coasts, sea ducks navigate a world unseen by most. Despite representing a significant portion of the continent’s duck species, these unique marine birds are among the least understood. Yet, unlike other waterfowl, many sea duck populations have declined, sounding an urgent call for our attention.

Meet the Sea Ducks

Out of the 21 species of sea ducks found around the globe, an impressive 15 call North America home! These birds are divided into several subgroups, including eiders, scoters, goldeneyes, mergansers, the harlequin and long-tailed ducks, and bufflehead. With specialized salt glands, they have become uniquely adapted to thrive in diverse habitats, from glacial lakes and estuaries to tree cavities in boreal forests. Most winter along the northern coasts of the Atlantic and Pacific Oceans and breed further inland across the Arctic tundra and taiga regions. Their beauty and unique behaviors captivate bird enthusiasts and hunters around the world and, for centuries, they have played an important role in the culture and food resources of many Indigenous communities.

Under the Shadow of Success

Over the past several decades, the visionary North American Waterfowl Management Plan and North American Wetlands Conservation Act have helped most waterfowl populations recover. However, sea ducks remain an exception. The 2022 State of the Birds report revealed a concerning 30% drop in their numbers since 1970. Two species – the spectacled eider and the Alaska-breeding population of Steller's eider – have been federally listed as threatened since 1997. Another two – the king eider and black scoter – were identified as “Tipping Point” species that have lost at least half of their population since 1970 and are projected to lose another half in the next 50 years if no action is taken.

FWS Scientist taking measurements of a long-tailed ducks head and bill length in the field
FWS Biologist measuring a long-tailed duck in Alaska | Image Details
Stepping Up for Conservation: The Sea Duck Joint Venture

A significant response to declining sea duck populations is the Sea Duck Joint Venture. Born out of the North American Waterfowl Management Plan in the 1990s, this bi-national collaboration between the U.S and Canada has been championing research and conservation for sea ducks and their habitats across the continent. Through this alliance, we at the U.S. Fish and Wildlife Service join forces with our colleagues from Environment Canada, Canadian Wildlife Service, U.S. Geological Survey, Bureau of Ocean and Energy Management, Ducks Unlimited, Birds Canada, all four Migratory Bird Flyway councils, and others.

Biologists searching for nests in the arctic tundra of Alaska
Biologists searching for nests in the Alaska tundra | Image Details

Together, the Sea Duck Joint Venture combined over two decades of research data and created the world’s first Sea Duck Key Habitat Sites Atlas. This Atlas identifies 85 of the most important habitats for sea ducks across North America and provides valuable insights about conflicts that could potentially impact the species or their habitats in the future. To compliment the Atlas, the Sea Duck Joint Venture has also created an open access interactive data visualization map. This tool has been instrumental in real-world applications, from being incorporated into the National Oceanic and Atmospheric Administration’s App to inform oil spill response and prevention to providing insights in Canada's Marine Spatial Plans for exploratory oil and gas drilling. Together, these resources are not only important to raise awareness of sea duck habitats across their range, but also to help us and our partners prioritize conservation efforts with more informed environmental assessments.

Coast to Coast

From the remote coasts of Alaska to the shared Salish Sea of the Pacific Northwest to the historic Nantucket Sound off the coast of Massachusetts, the key habitat sites identified for sea ducks are remarkably diverse, yet similar in the threats they face.


Two sites identified in Alaska are considered the top priorities for their importance to sea ducks protected under the Endangered Species Act. The Yukon-Kuskokwim Delta Key Habitat Site within the Yukon Delta National Wildlife Refuge was found to be one of two primary breeding habitats for the threatened spectacled eider in Alaska and has since been designated critical habitat for the species. This area is also home to one of the largest river deltas in the world.

South of the Yukon Delta area, on the north side of the Alaska Peninsula, the Izembek Lagoon resides within the Izembek National Wildlife Refuge. This remote area was designated critical habitat for the threatened Steller’s eider, as they especially rely on the lagoon during their molt, winter, and spring migration. Izembek is also remarkable in that it contains the largest eelgrass bed in the world, an ecosystem that supports the food sea ducks need during their non-breeding season. It is also important habitat for black scoters, red-breasted mergansers, and long-tailed ducks. As a low-lying habitat along the coast, these sites are particularly sensitive to climate change impacts like sea level rise and storms that impact fresh water many sea duck species need to rear their young.

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