Ecology of Cladophora
C. columbiana can be found in the mid to low intertidal zones on the Pacific west coast of North America, from Vancouver Island to Baja California. There are a variety of notable physical factors which often set zonation limits for marine species of Cladophora.
Limiting Factors in the Intertidal Zone
The wave tolerance of C. columbiana requires little comment, aside from noting the compact cushions are found in zones 2 and 3 intertidally, and can thus handle a significant amount of hydrodynamic force. By virtue of its dense and self-shading form, the alga rarely experiences photoinhibition except in the branches on the very top of the tuft, and thus tends to attach to solid substrate areas that are quite exposed.
As it is for all benthic intertidal organisms, space is at a premium, and competition may be vicious. C. columbiana seems to be an opportunistic settler, as its little clumps are usually found in limited and scattered areas competing with other algae like Pelvetia, Endocladia, and Mastocarpus for space. In addition, several marine invertebrates can be found trying desperately to edge out the green alga. Mytilus can almost always be found nestled in and around C. columbiana, and I've found, as well, several small Balanus barnacles imbedded in the alga, implying that in some cases, the seaweed effectively smothers the sessile invertebrates.
Cladophora interacts with other intertidal life in several ways besides just competition.
Types of Community Interactions
Grazed by invertebrates