It is a deep water coral found in the North Pacific Ocean, and plays an integral role in supporting benthic ecosystems.

Red tree corals grow axially and radially, producing structures of calcite and gorgonian skeletons that form dense thickets.

Due to the inaccessibility of sunlight below the photic zone, deep sea members of the Primnoidae family, such as Primnoa pacificia, do not have zooxanthellae symbionts.

Other soft corals, such as those responsible for building seafloor habitats like Primnoa pacifica, contain a calcite and gorgonian skeletal structure, more flexible than calcium carbonate.

A large population exists in British Columbia's Knight Inlet, where it occurs as shallow as 15 m deep on the crest of the sill that lies between Hoeya Head and Prominent Point.

Without photosynthetic symbionts to provide food and nutrients, red tree corals maintain a diet of mostly microscopic organisms and detritus.

[3] Red tree coral thickets are preyed on by the spiny Sea star Hippasteria phrygiana, the nudibranchs Tochuina gigantea and Tritonia tetraquetra and Calliostoma snails.

[4] These three dimensional structured thickets serve as main sources of habitat to bottom dwelling organisms in the many areas red tree corals populate such as the Gulf of Alaska.

[8] A multitude of fish and crab species depend on the thickets as breeding, feeding, and nursery grounds, including juvenile rockfish.

[8] Studies have shown that coral thickets in this area, coupled with sponge colonies, serve as a keystone species, their presence directly corresponding to biodiversity.

[4] In an effort to conserve the coral population, once a location of these deep sea oases is established, legislation protects the habitats by prohibiting bottom commercial activity in the surrounding waters.