Biological trend monitoring in the Netherlands

In 1989 biological monitoring activities in the Netherlands started in a national network of the marine and estuarine waters. These waters comprise the Netherlands portion of the North Sea, the Wadden Sea and the waters in the Delta region. This memorandum presents an overview of the activities in progress in mid-1990 and of activities planned for the near future, as well as some activities still under discussion. The present state of affairs with regard to all group of plants and animals currently being sampled and analysed is discussed in turn. The sampling locations or areas for each group/activity are given with the sampling frequencies. Sampling locations are shown on a detailed map.