THE HARBOR SEAL, PHOCA-VITULINA, IN THE OOSTERSCHELDE - DECLINE AND POSSIBILITIES FOR RECOVERY

Within a timespan of a few decades, the harbour seal almost completely disappeared from the estuaries in the south-west of the Netherlands. In 1960 a population of around 350 animals still lived in the Oostersc helde and Westerschelde area. About a quarter of this population lived in the Oosterschelde. At present less than 17 animals can be regularl y observed in the whole area. Human influences are responsible for the rapid decline of the population. Initially a high hunting pressure an d later environmental pollution are the main causes. Loss of habitat a nd disturbance at the resting places are additional important factors. The Oosterschelde still is a suitable habitat for seals. A short term natural development of a viable population in the area is not to be e xpected. Only with human help through active management, i.e. reintrod uction of rehabilitated seals (preferably originating from that area) and strict conservation of the extant Oosterschelde seal population, a ccompanied by environmental sanitation of the neighbouring waters, can the current southern Dutch harbour seal population increase.