Photo Pat O'Hara, Salish Sea in Focus 

The Salish Sea is one of the world’s largest and biologically rich inland seas. Its name pays tribute to the first inhabitants of the region, the Coast Salish.

The Salish Sea is an inland sea that encompasses Puget Sound, the San Juan Islands and the waters off of Vancouver, BC. The area spans from Olympia, Washington in the south to the Campbell River, British Columbia in the north, and west to Neah Bay and includes the large cities of Seattle and Vancouver.

Some of the world’s most successful businesses—Microsoft, Amazon, Boeing, and Starbucks—are headquartered in the region in large part because of the high quality of life that this remarkable body of water offers their employees and customers. 


  • Coastline length, including islands: 7,470 km
  • Total number of islands: 419 
  • Total land area of islands: 3,660 square kilometers
  • Sea surface area: 16,925 square kilometers
  • Maximum depth: 650 meters 
  • Total population: more than 8 million.
  • Number of different marine animals species estimated: 37 species of mammals, 172 species of birds, 253 species of fish, and more than 3,000 species of invertebrates (See Gaydos & Pearson 2011and Brown and Gaydos, 2011.) 
  • Number of species listed as threatened, endangered or are candidates for listing: 113 (See Brown and Gaydos, 2011.)
  • Check out some of the biggest species in the biggest and oldest species in the Salish Sea. 


Politically the Salish Sea is governed by the USA and Canada, but the international boundary separating the Puget Sound Basin (USA) from the Georgia Basin (Canada) corresponds to no natural barrier or transition, meaning the border is invisible to marine fish and wildlife.

Species listed as threatened or endangered under the US Endangered Species Act or the Canadian Species at Risk Act, including Southern Resident killer whales (Orcinus orca), marbled murrelets (Brachyramphus marmoratus), and some ecologically significant units or species of Pacific salmon (Onchorynchus spp.), traverse the boundary daily. Oceanographic processes such as freshwater inflows and wind driven surface currents exchange biota, sediments and nutrients throughout the larger ecosystem. Learn more about what makes an ecosystem healthy

The Challenge Before Us

In the blink of an eye, profound and disturbing changes have occurred in the Salish Sea. Increasingly, the sea and its surrounding watersheds are challenged by an ever-growing list of threats. Ocean acidification, a burgeoning human population, increased marine shipping traffic, and unchecked waste water and sewage runoff are just a few of the immediate pressures that are endangering this jewel of an ecosystem.

Most alarmingly, between 2008 and 2011, the number of marine wildlife species in the Salish Sea listed as threatened or endangered nearly doubled from 64 to 113. To compound the problem, a lack of regional decision- making has made it increasingly challenging to manage an ecosystem that stretches across two nations and encompasses hundreds of government entities—municipal, state, tribal and federal.

If healthy ecosystems foster economic prosperity, unhealthy ones represent lost opportunity and income. Whether we depend upon the ocean for our living or for our quality of life, we all benefit from a healthy Salish Sea.