The marine waters of Washington State are home to over 90 species of groundfish (or bottomfish), including rockfishes, Pacific cod, Pacific tomcod, Pacific hake (whiting), walleye pollock, sole, flounders, halibut, lingcod, ratfish, sablefish, cabezon, greenling, sculpins, red Irish lord, wolfeel, wrymouth, plainfin midshipman, sharks, skates, and perches. 

The fish species groups comprising groundfish populations occupy a variety of habitat types, from complex boulder and steep rocky reefs to cobble and sand and fine sediments. Quantifying the available habitats is important to understanding strategies for recovery actions. Forage fish are also important food resources for many groundfish species. 

A number of natural and human-induced factors are responsible for the overall decline in abundance of many groundfish species. These include historical over-harvest in the commercial and recreational fisheries, habitat loss from nearshore development, water quality, and shifts in food web resources. 

Studies show that the abundances of many groundfish populations in Puget Sound are below historical levels. Some of the species once common in fisheries declined to depressed or critical levels, resulting in reduced catches. However, in the fisheries monitoring data there are now some early signs of recovery. 

There are over 250 species of benthic invertebrates in Puget Sound, including a number of commercially and recreationally important species such as Dungeness crab and spot shrimp. Other species include sea stars, anemones, clams, and urchins. These species overlap with groundfish in habitat use and food resources.  

Twenty-eight species of rockfish are found within the Salish Sea, with two listed under the Endangered Species Act (ESA), yelloweye rockfish (threatened) and bocaccio (endangered). NOAA Fisheries has proposed listing the Sunflower Sea Star. Several other groundfish species are identified as Species of Greatest Conservation Need by the WDFW.