[4] This, in combination with their slow growth, makes the increasing disturbance to their habitats caused by fishing activities particularly impactful and difficult to recover from.

[1][8] Their details are tabulated below: Primnoa colonies are typically bushy in shape, heavily branched with no immediately visible main stem, though they do possess one.

[8] They are also ahermatypic, which means they aren’t reef building corals, but they still form large structures and are found in abundance in clusters of colonies.

They anchor themselves to hard substrates using calcareous discoid holdfasts, which are then further supported by growing layers of calcite at the base of the colony.

These hard substrates allow them to live in areas with strong currents, a preference which increases their odds of capturing food due to the higher velocity and volume of water passing through their branches.

The total bathymetric range occupied by the genus is between 6-1,020 m.[2] However, Primnoa being present in these shallow regions is due to a phenomenon known as deep-sea emergence, which is defined as “a phenomenon whereby organisms that typically dwell in the deep sea are able to exist in shallow-water areas because of unusual oceanographic conditions there.”[17] In this case, retreating glaciers have resulted in exposed bedrock and very cool temperatures that are similar to the deep-water temperatures preferred by Primnoa, as well as other factors that help mimic their natural environment.

The waters are cold and nutrient rich due to the active margins they inhabit, and experience large amounts of upwelling from the seafloor.

The benthic environments in which Primnoa are found provide the capacity for unique and highly diverse sponges and soft corals.

This region is home to the most productive fisheries of the Northern Pacific due to the benthic abundance and its capacity to support vertebrate species.

[2][19] Meaning they are restricted to the geographical range that spans the Aleutian Islands; however this diversity begins to increase west of 169°W.

[18] Because of their vital interactions with megafauna in these ecosystems, fisheries must integrate coral conservation into their practices, or otherwise risk disturbance to their entire industry.