It is commonly found in northern waters all around the world including both the Pacific and Atlantic Oceans to a northerly latitude of 81 degrees and as far south as Maine[1] (in the U.S.) and England.

They are eaten by a variety of predators, including sea stars, crabs, large fish, mammals, birds, and humans.

Acclimation and size are important factors as larger individuals have a lower surface area to volume ratio and can handle the increased osmotic tension.

This is a relatively fast growing sea urchin, and its age is generally calculable based on its size: one year for every 10 mm.

The spines attach to small tubercles on the test where they are held in place by muscles creating a ball and socket joint.

Tube feet are a structure that help Strongylocentrotus droebachiensis attach to the substratum for stabilization or locomotion, or to move loose food particles to the mouth.

The tube feet are quite flexible and can extend beyond the length of the spikes to reach the substratum or attach onto particles floating in the water.

The ampulla is a hollow bulbous structure that raises the tube foot above the skeletal plates that surround the lateral canal.

The movement of the tube foot depends on the hydraulic pressure of the water vascular system, and individual muscle action.

Historically thought of as parasites or larvae of the sea urchin, it is now commonly believed that the pedicellariae are actually part of the living creature.

The water vascular system is a series of canals through which fluid moves to help propel the podia of the sea urchin.

Along this entire distance, tube feet emerge from the lateral canal through the test to outside the epidermis of the sea urchin.

Strongylocentrotus droebachiensis eats by using a special appendage called an Aristotle’s lantern to scrape or tear their food into digestible bits.

Sea urchins all release their eggs or sperm directly into the water column at the same time to ensure fertilization.

Once fertilized, the gamete grows via mitosis and eventually becomes a larva capable of simple swimming called an echinoplutes.

Snails of the families Melanellidae and Stiliferidae live on the surface of the test and adhere their own eggs to the base of the spines as protection.

S. droebachiensis feeds on algae, preferring species like Sargassum muticum and Mazzaella japonica over Saccharina latissima, Ulva, and Chondracanthus exasperatus.

[6] In coastal Nova Scotia, a disease known as paramoebiasis can cause mass mortality events in S. droebachiensis, and exert a major control on abundance.

[8] Mass mortality events are strongly associated with water temperature (threshold ~12°C), but it is thought that storms may play a role in introducing the amoeba to susceptible populations.

The fishery is not regulated, and the green sea urchin is considered a pest in the Norwegian waters, eating up the kelp forest.