Halibut Cove Lagoon is a semi-enclosed embayment, about 0.7 miles (1 km) wide, on the southeast shore of Kachemak Bay, about 13 miles (21 km) east-southeast of Homer, Alaska. The lagoon was named after Halibut Cove and was first published by the U.S. Geological Survey in 1961. The lagoon has depths to 38 fathoms (70 m) but is isolated at low tides by a gravel bar which reduces the entrance to a swift, shallow stream. At high water, the navigable entrance channel is not well defined and requires local knowledge. A public dock at the south end is used by water taxis delivering hikers, and by local boaters.
A large-scale herring fishery began in 1911 to catch and process herring that came to spawn in Kachemak Bay and pods of beluga whales and harbor seals fed on the herring in Halibut Cove Lagoon. At the peak of the fishery 38 herring salteries operated in Halibut Cove to pack the herring in barrels for shipment. The fishery ended in 1928 when the herring population collapsed and the salteries stopped operating. Possible causes for the collapse include overfishing and pollution of the spawning areas. Large purse seines and gillnets were used to catch fish before they could reproduce, and the salteries dumped fish waste on the beaches and in shallow waters destroying spawning habitat.
Halibut Cove Lagoon and other shallow embayments in Kachemak Bay had extensive eelgrass beds, an essential habitat that supported a high abundance and diversity of marine fishes and invertebrates. Eelgrass also provides other important ecological functions such as oxygen production, nutrient recycling, erosion control, and contaminant filtration. In Alaska, eelgrass is often the preferred spawning substrate for the Pacific herring and provides rearing habitat in spring and summer for many commercial and forage fish species. Steller sea lions, seals, porpoises, belugas, and many species of birds ate large quantities of the fish as well as eggs that female herring deposited on eelgrass in the spring. The discarded fish waste from the salteries likely caused eutrophication of the poorly flushed embayments, effectively destroying the eelgrass habitat. Read more here and here. Explore more of Halibut Cove Lagoon here: