Koyuktolik Bay is approximately 2 miles (3.2 km) wide and situated near the entrance to Kachemak Bay on the southeastern shore of Cook Inlet, about 30 miles (48 km) southwest of Homer and 15 miles (24 km) southwest of Seldovia, Alaska. It lies at the southwest tip of the Kenai Peninsula and is also known locally as Dogfish or Dog Salmon Bay. The bay’s name originates from an Alutiiq village that existed there in the 19th century, as reported by the U.S. Coast and Geodetic Survey in 1908. Before this, colonial Russians referred to the bay as “Hiko-Bukta.”

The head of the bay features a large lagoon partially enclosed by a gravel spit. The lagoon supports an extensive eelgrass bed surrounded by salt marshes. An earthquake on March 27, 1964, shook the Kachemak Bay area for about three minutes, resulting in a mainland subsidence of 2 to 6 feet (0.6 to 1.8 m). The quake also caused differential compaction of unconsolidated gravel, leading to additional elevation drops on beaches, river deltas, and spits. For example, the Homer Spit subsided approximately 6 feet (1.8 m) due to gravel compaction. A similar amount of subsidence likely occurred on the spit at Koyuktolik Bay.

The subsidence of the highly permeable gravel spit led to saltwater intrusion into the freshwater aquifer that sustains the coastal margin spruce forest. Because saline water has a higher mineral content, it is denser and exerts greater pressure than freshwater. Consequently, saltwater can push inland beneath freshwater. Following the land subsidence, many spruce trees on the spit and along the shoreline died due to saltwater intrusion, resulting in extensive ghost forests of standing dead trees. Spruce trees have since returned, growing on gravel storm berms above the tide’s influence. Read more here and here. Explore more of Koyuktolik Bay and Cook Inlet here: