Forester, E.B., 1985, Zoogeography, biofacies, and systematics of ostracode assemblages from continental shelf sediments, Gulf of Alaska: University of Colorado, Boulder, Ph.D. dissertation, 264 p.
The systematics, zoogeography, and biofacies of the ostracode taxa from 373 bottom grab samples taken in the northeast Gulf of Alaska were studied. 162 ostracode species representing 56 genera are recognized (32,610 valves), of which 138 constitute new species; three new genera are proposed. The Gulf of Alaska forms a large geographic portion of the cold temperate Aleutian Zoogeographic Province. The ostracode taxa presently living in the Gulf are utilized in characterizing the Aleutian Province and in refining the northern provincial boundary. The continental shelf sediments are believed to range in age from Pliocene through Holocene, with large regions of outcrops and/or relict sediments preserved on submarine banks. Multivariate analysis delineated five taxonomically distinct assemblages; four assemblages represent depth biofacies and can be correlated with the depth gradients of major physical and chemical parameters. The depth biofacies are: Assemblage I, inner sublittoral (0-50 m); Assemblage II, middle sublittoral (50-100 m); Assemblage III, outer sublittoral (100-200 m); Assemblage IV, upper bathyal (200-500 m). Boundaries between the depth biofacies correspond to large-scale changes of water temperature, salinity, and dissolved oxygen, and lesser to turbidity, substrate type, nutrient supply, and wave and storm activity. Assemblage V is composed of extinct species and of species that are locally extinct and represent habitats that no longer exist in the Gulf of Alaska.
Theses and Dissertations
