The harbour seal,Phoca vitulina,in the Oosterschelde: decline and possibilities for recovery

Within a timespan of a few decadesm 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 Oosterschelde and Westerschelde area. About a quarter of this population lived in the Oosterschelde. At present less than 17 animals can be regularly observed in the whole area. Human influences are responsible for the rapid decline of the population. Initially a high hunting pressure and later environmental pollution are the main causes. Loss of habitat and 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 expected. Only with human help through active management, i.e. reintroduction of rehabilitated seals (preferably originating from that area) and strict conservation of the extant Oosterschelde seal population, accompanied by environmental sanitation of the neighbouring waters, can the current southern Dutch harbour seal population increase.