The above graph are the results of a one-day assessment of the vertical distribution and percent cover of P. pacificum at Pigeon Point, San Mateo County, California (April 1999). There was an increase in the amount of space covered by P. pacificum in the lower intertidal areas. Overall, this site had little P. pacificum compared to other sites with a greater vertical slope. At Pigeon Point the vertical slope is gradual with many small water channels linking tidepools that go all the way up to the high intertidal zone. The area also has many rocks that create shade, as well as drier areas in the low and mid intertidal zones. The specimens that were counted were usually found under Mazzaella spp. in the same manner that they have been seen under the Phyllospadix sp. This is because when P. pacificum is in intertidal areas, it tends to be shaded.