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Kachemak Bay

Site Facts

Country, State, Province/Region:

United States of America, Alaska

Relative Location:

Kenai Peninsula, City of Homer.


59° 25’20.03” N to 59° 46’02.24” N, and
150° 59’39.54” W to 151° 53’01.21” W



Basis for Designation:

Supports more than 100,000 shorebirds annually. 


232,462 acres (94,074 hectares)


March 1995

Site Owner/Steward:

City of Homer, and Alaska Department of Fish and Game (ADFG)

Site Partners:

Alaska Maritime National Wildlife Refuge, Kachemak Bay National Estuarine Research Reserve (NOAA and ADFG), Kasitsna Bay Laboratory (NOAA and University of Alaska Fairbanks), Kachemak Bay State Park and State Wilderness Park, Audubon Alaska, Kachemak Bay Birders, Kachemak Bay Conservation Society, Cook Inlet Keeper, Homer Chamber of Commerce, Kachemak Heritage Land Trust, Pratt Museum

Human Population within 100 km:

Approximately 13,000


George Matz
Kachemak Bay Birders


About Us

Kachemak Bay is a funnel-shaped fiord 40 miles long and 24 miles wide in Alaska’s Cook Inlet region. It has a seasonal marine climate of sunny springs, cool and cloudy summers, wet falls, and mild (for Alaska), snowy winters. Its beautiful collage of ocean, sandy and rocky beaches, spruce forests, rolling hills, and jagged mountains with blue glaciers supports an abundance and diversity of flora and fauna, including 244 species of birds. 

Black Turnstones in Flight
Photo by Gary Lyon

Most of Kachemak Bay is undeveloped and its lands and water have extensive habitat protection. Virtually the entire bay is a State Critical Habitat Area and a National Estuarine Research Reserve; Mud Bay/Mariner Park Lagoon is owned by the City of Homer; and the Fox River Flats Critical Habitat Area (CHA) is managed by the Alaska Department of Fish and Game. The number of shorebirds in just the latter two areas within the bay merited its designation as a WHSRN Site of International Importance.

Kachemak Bay's 320 miles of shoreline and 30-foot tidal range create the substantial intertidal areas that attract some 36 species of shorebirds. The collection of worms, bivalves, crustaceans, and other organisms in the mudflats of Mud Bay and Mariner Park (respectively east and west of Homer Spit) provides rich feeding grounds for an extraordinary number of migrating shorebirds. Similarly, the expansive intertidal mudflats and complex of low-lying marshlands of the Fox River Flats CHA offer vital habitat for thousands of waterfowl and a million or more shorebirds to rest, loaf, and feed during migration. The most numerous shorebird species is the Western Sandpiper; Dunlin and dowitchers are also prominent. The importance of Kachemak Bay is detailed in the Western Sandpiper and Dunlin Species Conservation Plans.


In early May, birdwatchers travel from all over to Homer for its annual Kachemak Bay Shorebird Festival to celebrate the spectacular spring migration there. Festival participants can choose between over 50 different events, from advanced ornithology workshops, beginning backyard birding presentations, field trips and boat tours to arts events and children's activities. More information can be found on the website of the Homer Chamber of Commerce or find them on Facebook.

There are three other WHSRN sites along the southern Alaskan coastline. Copper River Delta is a Hemispheric Site also on the Gulf of Alaska, east of Kachemak Bay. Kvichak Bay and Nushagak Bay are Regional Sites just west of the base of the Alaska Peninsula.

The Kachemak Bay Birders release an annual report for the Kachemak Bay Shorebird Monitoring Project. More information on this citizen science project can be found in the Special Information section.

2014 Kachemak Bay Shorebird Monitoring Report (.pdf)

Ecology & Conservation

There are literally two sides to the Kachemak Bay story, as paraphrased below from the Kachemak Bay National Estuarine Research Reserve's management plan: 

Rock Sandpiper and Wandering Tattler
Photo by Tami Reiser

The head of Kachemak Bay is characterized by extensive tidal flats, braided drainages, and marshlands. Beyond that, the northern and southern sides of the watershed have dramatically different geomorphology, geology, climate, vegetation, soil, and hydrology characteristics. 

NORTH:  gentle topography; much more extensive river systems; melting snow and rain drive the hydrologic system, including the Anchor River; rolling hills and gentle slopes are underlain by sedimentary rock; drier, flatter topography supports a mixed deciduous/conifer community transitioning to tundra; shoreline consists of cliffs, composed of sand and clay, leading down to shallow mudflats.

SOUTH: steep topography; glaciation limits the length of the rivers; early-summer snow melt and late-summer glacial melt influence the hydrologic system; jagged, glaciated peaks are underlain by ancient bedrock; wetter, steeper slopes (as a result of higher annual snow and rainfalls) support temperarate rain forest habitat; shoreline consists of hard rock cliffs and deep embayments. Many islands are also found along the southern shore.  

The Homer Spit bisects the Bay into inner and outer zones that differ in freshwater influence and in wave action, having a dramatic impact on the Bay's circulation. Water masses from these zones meet during the Bay's daily tidal cycle.

Wintering Rock Sandpipers
Photo by Kevin Co

Some 244 species of birds have been identified on and around Kachemak Bay, the most important marine bird habitat in Lower Cook Inlet. During winter months, over 90% of the the birds in the Inlet are found here. The bay's inner coastline supports a total estimated density of 1,758 birds/km2 (679 birds/mile2) year-round. During spring migration, large flocks of sandpipers, Dunlin, plovers, dowitchers, godwits, yellowlegs, and Whimbrel prefer the inner Bay for its greater abundance of clams. Turnstones, Surfbirds, Black Oystercatchers, and Wandering Tattlers are attracted to the bay's rocky islands, while large numbers of Red-necked Phalaropes are seen on the water. 

Except for half of the Homer Spit, much of the shorebird habitat in Kachemak Bay has little disturbance from human activity. The Cook Inlet region receives a lot of geologic activity, however, that has and/or will alter intertidal areas. Although the Exxon Valdez oil spill occurred hundreds of miles from here, some oil did stain Kachemak Bay waters. Shipping poses possible threats to the bay, where the protected waters of the inner bay is considered a port of refuge for disabled and leaking ships. Foreign ships also frequently anchor in the bay with the potential of introducing invasive species.

The Kachemak Bay area has significant scientific facilities to study and monitor its ecological condition. In Homer, the KBRR and the Alaska Maritime National Wildlife Refuge share a large facility and visitor’s center, State resource management agencies are present, and the University of Alaska Anchorage - Kenai Peninsula College has a campus. The University of Alaska Fairbanks and NOAA operate the Kisitsna Bay Lab on the south side of the Bay.



Special Information

Many avid birders in the Kachemak Bay area routinely make observations and participate in citizen-science projects. The Homer Christmas Bird Count has been ongoing for 30 years, and the popular Homer Shorebird Festival has been an annual event since 1993.

George West, former Homer resident and Professor Emeritus of Zoophysiology from the University of Alaska (now living in Arizona), conducted shorebird surveys on the Homer Spit and other parts of Kachemak Bay more than two decades ago (late 1980s/early 1990s). These surveys were instrumental in designating the Kachemak Bay WHSRN Site. West wrote the Shorebird Guide for Kachemak Bay and Homer, Alaska booklet, summarizing his efforts. 

In 2009, the newly organized Kachemak Bay Birders reinstated Kachemak Bay shorebird surveys using the International Shorebird Survey protocol. From the executive summary of the 2014 report(.pdf):

In May 2014, Kachemak Bay Birders (based in Homer, Alaska) completed its sixth consecutive shorebird monitoring project. The main purpose of this citizen science project is to attain a better understanding of the status of shorebird populations in the Kachemak Bay area, particularly during spring migration. We continued our efforts to include monitoring at the nearby Anchor Point/River and the Kasilof River. By comparing our current Homer Spit data to monitoring data collected by former Homer resident George West, who conducted counts of Homer Spit shorebirds during the 1980s and 1990s, we will have a better understanding of population trends. Secondary purposes for this project are: 1) to contribute information that might be useful to others assessing shorebird populations across the entire Pacific Flyway: and 2) to use the monitoring data to help protect Kachemak Bay/Homer Spit shorebird habitat.


Fox River Flats Critical Habitat Area
Joe Meehan 
Coordinator for Lands and Refuge Program
Alaska Department of Fish and Game
(907) 267-2281

Mud Bay/Mariner Park Lagoon
Julie Engebretsen
City of Homer Planning Dept.
(907) 235-8121

Kachemak Bay
George Matz
Kachemak Bay Birders