During the six-month period of July through December, 1966, a study of animals inhabiting laminarian holdfasts in Yaquina Bay, Oregon, was carried out to determine what animals live in this habitat and to gain some idea of the factors which influence their presence and distribution. This study deals with yet another facet of the ecology of this Oregon estuary, which has been the object of intensive biological, geological, and hydrographic studies for the past several years. Fifty samples were collected and analyzed and found to contain a total of 6,687 individuals representing 99 taxa. Identification was carried to species as far as possible although several individuals were juvenile or incomplete and so could be determined only to higher taxonomic levels. Some species showed limited distributions, but most species were widespread spatially and seasonally. The species composition of the samples at a given location was quite constant throughout the period of sampling, but at each time of sampling it varied markedly among different locations in the bay. Since the animals found in holdfasts also occurred in other situations offering shelter and evidently readily moved from one holdfast to another, it was impossible to define any unique holdfast community. When the animals taken were lumped by group, the most numerous were polychaetes, which comprised twenty-eight percent of all of the individuals. Other groups present in relatively large numbers were pelecypods, nematodes, cirripedes, and gastropods. There have been no other studies of holdfasts-inhabiting animals in estuaries reported from the Pacific coast, so the results found were difficult to compare with other findings. Other surveys have been made on this coast which dealt with animals living in holdfasts in oceanic situations, and the results of the present study were somewhat comparable to them. / Graduation date: 1967

Graduation date: 1978 / Best scan available. p.127-235 of original are skewed. p.156-191, 208-235 are photocopied from a computer code print out.

Graduation date: 1980