Slowly changing phenomena - whether natural or anthropogenic - are often only detectable over a long period of time. Climate changes, the stealth progression of foreign species, and the decrease of biodiversity are well known examples. To enable future research of such a phenomena it is therefore essential to set up monitoring activities, to maintain them over a long period of time, and to build up consistent, multidisciplinary and freely available data series.

Or qouting the European Science Foundation's Marine Board :
While the properties of marine ecosystems will undoubtedly be altered by climate,the lack of systematic knowledge of long-term ecosystem responses makes it difficult to predict these changes.Predicting the response and feedback of marine biota to climate change is required.Impacts of climate change are being attributed to evidence of community shifts,arrival of tropical species in temperate waters,occurrence of Mediterranean species in the North East Atlantic, and in anomalous North Atlantic Oscillation (NAO)cycles affecting distribution and abundance of phytoplankton,zooplankton and fish species.It is essential to continue long-term monitoring in order to differentiate seasonal, annual and decadal variability and anthropogenic change. - The Integrating Marine Science in Europe. ESF Marine Board Position Paper, November 2002.

Since April 2002 the Zeeleeuw sails every month along the Belgian coastal waters, measuring basic waterparameters, and collecting water- and sediment samples. The samples are analysed by a group of experts of different disciplines, the results are collected in a database, and then made available online.

We measure along the existing inshore-offshore and east-west gradients and cover the complete Belgian coastal area in a one-day trip.
On a seasonal basis the monthly cruises are complemented with hourly measurements over a 13-hour period to supply information on tidal fluctuations.

By keeping up this monthly monitoring campaign we will collect a unique long-term dataset, that will proof useful to researchers, policy makers and the general public alike.