Masters Thesis

The association of sediment size and natural enrichment with littoral foraminifera, Año Nuevo Point, California.

An important aspect of any group of organisms from both ecologic and evolutionary points of view is the part played by that group in channeling the flow of energy within the community in which it lives. Foraminifera, marine protozoans with calcium carbonate or sand grain (agglutinated) tests, are recorded as feeding chiefly upon bacteria, small diatoms, and nannoplankton in a wide variety of marine environments (Myers, 1943; Bradshaw, 1961; Lee et al., 1966; Muller and Lee, 1969; Murray, 1963). Myers (1943) found the diet of foraminifera includes soft-bodied flagellated organisms such as gametes of larger algae as well as filamentous algae, minute eggs, spores, and cysts. Their food items are usually below 25 y in size (Lipps and Valentine, 1970). Predators upon foraminifera range from highly specialized microcarnivores that feed largely on foraminifera to less selective ones that include foraminifera in a mixed diet and to generalized feeders that ingest foraminifera along with much other material (Lacaze-Duthiers, 1856; Mare, 1942; Graham, 1955; Morton, 1958; Lipps and Valentine, 1970). The present study considers the effect of organic enrichment on the abundance and diversity of intertidal benthic foraminifera. This requires an understanding of regional differences in their habitat and local variations of rnicroenvironments within that habitat. Sediment is an important microhabitat feature and must be included in a complete study of foraminifera! assemblages.