Endocladia muricata competes for space with other algal species, as well as, invertebrates (1). In some habitats, the colonization of an area depends on the presence or absence of mussels. When mussels are removed by a predator, Endocladia is able to colonize the newly available space (2). In some areas within Endocladia's habitat range, it grows on the shells of mussels found in the high intertidal.
Endocladia muricata provides habitat for many high intertidal species. Many species of algae and invertebrates use the canopy created by Endocladia as shelter from the stresses of the high intertidal (3). For example, the larvae of Mytilus trossulus prefer to settle in the turf habitat created by Endocladia thalli (1).Some organisms that can be found living within Endocladia include amphipods and the petrocelis stage of Mastocarpus papillatus.
Due its location in the high intertidal Endocladia faces intense heat stress on a regular basis. Hunt and Denny (2008) found that Endocladia was still able to photosynthesize after being exposed to air temperatures of up to 47°C. Endocladia is also able to survive in water temperatures of up to 28°C (1). Based on Endocladia’s ability to survive these extreme temperatures, it can be said that it is one of the most thermally tolerant algae on the West coast (1).