In spring 1984, a time series of oceanography parameters was investigated of Cap Timiris Canyon (off the Islamic Republic of Mauritania, NW Africa). In all observed oceanographic parameters, pronounced variations were detected in time. The results give a hint of a period of nine days, which is supposed to correspond to the effect of the canyon. In the area of the canyon head the effect of freshly upwelled water was observed on the distribution of physical, chemical and biological parameters. The time scales of physical and biological processes have been compared with the results of plastic bag experiments run parallel to the time series. Because of the short distance between the canyon head and the anchor position, the observed variations are related mainly to changes caused by the canyon, which is partly responsible for the inhomogeneous oceanographic distributions.