Shoreline changes at the embayed coastline between Ohata fishing port and Shiriyazaki Point in Shimokita Peninsula were investigated by field observation and reading of aerial photographs. In this area, swells are incident from NE mainly in summer, whereas NW wind blows in winter causing rough wind waves. Since the shape of the coastline is semicircular and eastern half of the coastline is well protected by the peninsula itself against summer swells, predominant direction of littotal drift is eastward. Large shoreline recession with the formation of sea cliff was observed on the east side of harbor and detached breakwaters.
