10. Dixon Entrance/Langara Island/Forrester Island

Site Overview

Dixon Entrance is a transboundary water body between southeast Alaska and British Columbia’s Queen Charlotte Islands (QCI), connecting to Hecate Strait to the south. Situated on the continental shelf, it is a largely shallow area, with few places deeper than 300 meters (980 feet). Forrester and Langara Islands are located at Dixon Entrance’s opening to the Pacific Ocean on the US and Canadian sides, respectively. The east and south sides of Dixon Entrance receive small amounts of freshwater input from mainland British Columbia’s fjord estuaries and from QCI rivers. Tidal mixing is the dominant oceanographic influence. The Haida Eddy originates off the northwest coast of QCI, transporting nutrients offshore toward the southwest. Rose Spit Eddy circulates in eastern Dixon Entrance.

Kelp and eelgrass line the coastal seafloor, providing suitable habitat for sea otter and spawning sites for herring. A concentration of red-tree corals (Primnoa spp.) is located at the west end of Dixon Entrance on Learmonth Bank. Many commercially important invertebrate and fish species are present here, including sablefish, Pacific Ocean perch (Sebastes alutus), rougheye rockfish (S. aleutianus), lingcod (Ophiodon elongatus), Dungeness crab (Cancer magister) and geoduck clam (Panopea abrupta).

Many marine birds rely on, and are part of, this biologically diverse ecosystem. Cormorants (Phalacrocorax spp.), gulls (Larus spp.) and small alcids are a common sight. Black-legged kittiwakes catch fish at the sea surface while common murres and rhinoceros auklets (Cerorhinca monocerata) swim underwater in search of prey. More than 10,000 pairs of ancient murrelets breed on Langara Island along with cormorants. There are also minor nesting sites for Cassin’s auklet, black oystercatcher (Haematopus bachmani) and pigeon guillemot (Cepphus columba) near Langara Island (Harfenist et al. 2002). The marine waters around Langara Island are also important for marbled murrelet, considered vulnerable by IUCN and listed as threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). A wide variety of shorebirds reside and nest on the islands as well.

Both the transient and resident stocks of threatened killer whales are spotted year round. Humpback whales, also listed as threatened by COSEWIC, migrate through the coastal waters southward in the fall and northward in the spring from breeding grounds in Mexico and Costa Rica. This area is also part of the migratory route of the fin whale, which receives a “special concern” status from COSEWIC in Canada and is considered “depleted” in the US under the MMPA.