Gulf of Alaska Coastal Rivers & Streams - A Global Ecoregion
One of the most important areas of the world for migrating fish
Snapshot: Ecoregion 177
Size:
882,000 sq. km (360,000 sq. miles)
Habitat type:
Small Rivers
Geographic Location:
Upper western coast of North America: from southern Canada across to the Kenai Peninsula of Alaska. Includes the Alexander Archipelago, the Queen Charlotte Islands, and Vancouver Island
Conservation Status:
Relatively Stable/Intact
Did You Know!
Many of the islands in the Gulf of Alaska are actually the tops of mountains that were submerged when glaciers melted thousands of years ago. About 11,000 mountain tops make up the islands of the Alexander Archipelago. Vancouver Island still keeps much of its old identity; several peaks there are more than 6,800 feet (2,100 m) tall.
About the Area
With more than 196 inches (500 cm) of rain each year, this ecoregion is particularly important for its high concentrations of anadromous fish (those that migrate from freshwater to the ocean and back to freshwater).
These species serve as keystone elements by transferring marine-derived nutrients to the freshwater realm on an annual basis.Parts of this ecoregion escaped glaciation and harbour localised endemics, particularly among cave-dwelling invertebrates.
Local Species
Species include Arctic lamprey (Lampetra japonica), Broad whitefish (Coregonus nasus), Alaska whitefish (C. nelsoni), Arctic cisco (C. autumnalis), Angayukaksurak char (Salvelinus anaktuvukensis), and numerous anadromous Salmon (Oncorhynchus tshawytscha, O. nerka, O. mykiss, O. gorbuscha, O. keta, and O. kisutch).
Endemic fish species include the Olympic mudminnow (Novumbra hubbsi) and Salish sucker (Catostomus sp.). The white sturgeon found here is the largest freshwater fish in North America, reaching lengths of up to 20 feet (6 m)!
Threats
Destructive logging practices are the largest and the most extensive threat. Additionally, population pressures, expanding agriculture, pollution, oil spills, pipelines, dams, and overfishing cause problems for migrating fish and other species of this region. There is growing concern that warming ocean temperatures may adversely affect migrating salmonids during the oceanic portion of their life cycle.
Resources
• NationalGeographic.com
