Port Walter is a fjord 3.7 miles (6 km) long that opens into Chatham Strait on the southeast coast of Baranof Island, about 91 miles (146 km) west of Wrangell and 51 miles (82 km) south-southeast of Sitka, Alaska. The fjord includes a small embayment near the entrance called Little Port Walter and a large sheltered basin near the head of the fjord named Big Port Walter. The name was first published in 1901 by the U.S. Coast and Geodetic Survey. Big Port Walter has depths of 22-54 fathoms (40-98 m) and is entered through a narrow passage 0.4 miles (0.6 km) long and only 0.18 miles (0.3 km) wide. A large stream cascades into the basin from a lake at an elevation of about 530 feet (162 m). The ruins of a wharf from an abandoned herring reduction plant are at the head of the bay. Herring were historically abundant in Southeast Alaska and were traditionally harvested for roe, oil, meat, and bait from the earliest recorded history of the coast. Tlingit oral tradition emphasizes that herring eggs were highly valued and sought after as food. Herring were particularly prized because they were present throughout the year in select places, unlike the more migratory salmon, and also because they returned to nearshore spawning areas in late winter and early spring at precisely the time when winter food stores were running low and fresh sources of meat, oil, and protein were at a premium. Two to three months before spawning in late March or early April, herring might be present in known spawning bays in vast quantities, where they could be raked, jigged, netted, or trapped to be eaten fresh, smoked, or rendered into oil. The early maritime fur traders had little interest in herring and little is known about the fishery until 1887 when the U.S. Commission of Fish and Fisheries sent Jefferson F. Moser on the USS Albatross to document the commercial fisheries in Alaska.

Herring have supported Alaska Native subsistence fisheries that predate recorded history and are still practiced today. For example, it is well known that the spring harvest of herring eggs on kelp or hemlock boughs has always been an important subsistence resource in coastal communities. Early European explorers and traders who were familiar with the Atlantic herring undoubtedly utilized Pacific herring for food as well as bait for catching salmon and halibut. They also preserved herring with salt in wooden barrels, as they had done in the North Sea. No records of the amount of herring used, traded, or exported are available prior to the purchase of Alaska from Russia in 1867 and for more than a decade afterward. The North West Trading Company began operations at Killisnoo, near Angoon on Admiralty Island, as a shore whaling station and trading post in 1878. In 1882, when whales became more difficult to catch and less profitable, the company built the first herring reduction plant. In 1887, Moser on the USS Albatross described the operation for the U.S. Commission of Fish and Fisheries. Reduction fisheries ‘reduce’ herring to fish meal and oil and the plant at Killisnoo produced 30,000 gallons of herring oil annually, representing over 10 million fish. Depending on the time of year, a barrel of herring that contains 700 fish provided about 0.5 gallons (1.9 l) of oil in the spring, 3.5 gallons (13.2 l) in the summer, and 2 gallons (7.6 l) in the winter. During the 1920s, herring became increasingly valued for oil and guano (fish meal), and competition with many other reduction plants opening in Chatham Strait as well as the decline of the local herring population caused the Killisnoo plant to close in 1928. There is very little documentation about the additional herring reduction plants that sprang up in southern Chatham Strait during the 1920s, probably because most did not last long. In 1917, the Alaska Herring and Sardine Company built a herring saltery in Big Port Walter, but after 2 years sold to Southern Alaska Canning Company, and the facility was used to salt herring. A wooden pipe was laid down the mountain from the lake above to generate electricity. The cannery closed in 1922, and the facility was sold to Pacific American Fisheries in 1929 but remained idle. In the late 1940s, the cannery was used as a herring reduction plant. Fish oil was pumped into two holding tanks on the pier until the weight of the oil caused the pier to collapse and the operation was abandoned. In 1949, there were 37 herring oil reduction plants in Southeast Alaska, but output had been declining for 20 years mostly due to declining herring stocks, and in 1966, the last reduction plant at Washington Bay on Kuiu Island was closed.

Pacific herring are a critical foundation of the marine and terrestrial food web and at different stages of their life cycle are preyed upon by ducks, gulls, eagles, salmon, halibut, otters, seals, sea lions, whales, and terrestrial mammals including mink and bears. Despite their ecological importance, relatively little is known about the larval and juvenile biology of herring, and adult overwintering areas, feeding areas, and migration routes are not well understood. Spawning begins in late March in Southeast Alaska when adults swim to sheltered nearshore areas. Males and females release their milt and eggs into the water column where they mix and fertilize. The eggs are adhesive and attach to vegetation or the bottom substrate. The eggs hatch into larvae within two to three weeks of fertilization. Larvae have limited capacity for propulsion in their early stages and are initially dispersed by local wind-driven currents. Survival depends on their ability to ride more stable regional currents toward relatively protected areas such as bays and kelp forests where they can better escape predation and grow. They are aided in this initial odyssey by a yolk-sac which provides critical nutrients and ballast during the first week of this vulnerable stage in the life cycle. As they mature, herring larvae eventually shed their yolk-sacs and become dependent on planktonic food. By their third month, herring become more mobile and begin to school, and at 10 weeks of age, the larvae begin to assume adult form. The importance of sheltered bays for rearing habitat is critical at this stage of development. In the fall, the schools of juveniles move to deeper water where they will spend the next 2-3 years. The first winter the juveniles form balls that are likely bound to the availability of food as well as protection from predators. They exhibit a diel vertical migration pattern, remaining near the bottom during the daylight hours and moving to shallow waters to feed at night. Juveniles will remain separate from the adult population until they are sexually mature at 3–4 years of age and spawn every year after reaching maturity. Adult schools of herring are characterized by a mixed age structure, ranging from 3-12 years in Southeast Alaska. The diversity of age classes within a local herring population contributes to its stability and resilience. Adult schools tend to range more widely than juvenile schools, according to the availability of food. In the spring, water temperature is a key trigger for spawning and the schools will repeatedly swim to nearshore waters to spawn then return to offshore waters to feed. Read more here and here. Explore more of Big Port Walter here: