Portland State University. Department of Geography
John O. Dart
Date of Award
Master of Science (M.S.) in Geography
1 online resource (126 pages)
Nature -- Effect of human beings on -- Oregon -- Netarts Bay, Nature -- Effect of human beings on, Oregon -- Netarts Bay
Problems associated with planning the future use of estuarine areas stem from:
- A lack of knowledge on the critical aspects of the system.
- Inability to predict the future changes which will occur within the system in order to effectively manage the resource base.
These difficulties lie in the fact that changes within the system occur because of both "natural" and "cultural" conditions. The thesis hypothesis and subsequent research is to describe the physical changes that have occurred within the Netarts system, primarily due to man's impact.
Types of data gathered for the analysis includes that on historical and current land use activities, current research findings on system characteristics, and independent research on shoreline changes and vegetation composition. Much of the historical data were taken from early manuscripts and publications. Current research data were obtained from several engineering studies of the bay, as well as a baseline study of Netarts funded by a grant from the National Science Foundation and Oregon State University. This study included an inventory of man's utilization of the resource base. Methods utilized in data analysis included aerial photo-interpretation, planimetric measurement of shoreline and vegetative alterations, and on-site inventory of current shoreline and vegetation changes.
Results of the research have shown that it is possible to measure and describe changes within the Netarts Bay system. Specific findings include:
- A decrease in sandspit volume of nine percent between 1942 and 1974 due to construction of a boat basin and fill.
- Occurrence of marsh progradation in all marsh areas with sedge and low sand type showing the greatest increases between 1939-1962.
- A decrease in rate of marsh progradation from 1962-1974.
- A total decrease in tidal prism of the bay between 1957-1969 as measured by cross sectional areas. The rate of decrease is occurring at a faster rate south of the mouth of Whiskey Creek.
- Destruction of Chum salmon fisheries and native oyster populations due to over-harvesting and siltation.
- Destruction of Gaper clam beds along the eastern shore of the bay and increased erosion of the shore, due to road fill and road construction.
The results of the research and subsequent findings show that it is possible to describe an estuary as a "system" that has applicability for future development of a land and water use model for an estuary.
McCallum, Larry D., "Netarts Bay, Oregon: an assessment of human impact on an estuarine system" (1977). Dissertations and Theses. Paper 2550.