The vertical distribution of 12 benthic marine algae and one animal are described for Indian Arm, an inlet in British Columbia. In general, the vertical distributions had distinct limits and the relative vertical positions of the species were constant throughout the inlet. The relative vertical distributions of the biota within the inlet are essentially the same as described for the northeast Pacific by other authors concerned with the same biotic elements. However, the upper limits ofLaminaria saccharina(L.) Lamouroux,Costaria costata(Turn.) Saunders, andConstantinea subuliferaSetchell are from 1 to 3 m lower within the inlet than elsewhere, whereas those ofAgarum cribosumBory,Fucus evanescensC. Agardh, andSargassum muticum(Yendo) Fensholt are essentially the same within and outside of the inlet. For the remaining species studied (Enteromorpha compressa(L.) Greville,E.linza(L.) J. Agardh,E.intestinalis(L.) Link,Monostroma fuscum(Postels & Ruprecht) Wittrock,Ulva lactucaLinnaeus,Navicula grevillei(C. Ag.) Cleve, andBalanus glandulus(Darwin)) there were no comparable distribution data outside of the inlet.Available data suggest the deepening of the upper limits of some algae in Indian Arm reflects their intolerance to the high temperature and low salinity of the surface waters of the inlet.