Species of concern are native species, sub-species or ecologically significant units that warrant special attention to ensure their conservation. The number of species of concern within an ecosystem can be used as a crude measure of ecosystem health. Within the Salish Sea, four jurisdictions assess which species require special initiatives to ensure protection and survival of the population: the Province of British Columbia, the State of Washington, the Canadian Federal Government, and the United States Federal Government. Also known as marine species at risk, the number of species of concern in the Salish Sea is used by the US Environmental Protection Agency and Environment Canada as a transboundary ecosystem indicator. As of November 15, 2013, there were 119 species at risk in the Salish Sea, almost twice the number of species at risk when the indicator was first established in 2002. While some of this increase represents an increase in the number of fish, bird and mammal species known to use the Salish Sea, most additions represent new listings due to concern about declines in populations. In terms of species richness, currently 35% of mammal species, 32% of bird species, 17% of fish species, 100% of reptile species, and less than 1% of macro invertebrate species are listed by one or more jurisdiction. The high proportion of species of concern is suggestive of ecosystem decay and we recommend that it is time to consider the Salish Sea an ecosystem of concern.