National evaluation report on the Joint Assessment and Monitoring Programme of the Netherlands 2005

The Netherlands participates in the Joint Assessment and Monitoring Programme (JAMP) of the Oslo and Paris Commissions. In this framework it was agreed that all members or contracting parties should report on the national comments that accompany the data submissions to ICES database. This report presents the results and comments of the Dutch contribution to the JAMP programme 2005. Over the whole monitoring period (ca. 15 yrs) wintertime concentrations of DIN and DIP were in agreement with earlier reported downward trends. Additionally, though both nutrients still exceed their respective MTR (Maximum Tolerable Risk concentration), the downward trend determined in 2005 for the last decade appears more progressive for DIN than for DIP (especially in coastal zones). Of all measured dissolved heavy metal concentrations only copper was recurrently exceeding MTR levels and of all measured heavy metal concentrations in sediment the yearly means of As, Cd, Pb, Hg, Zn, and Cr were occasionally exceeding the VR. Furthermore, recently concentrations of Cr, Ni Pb showed an upward trend in Mussels. A long term assessment of ?-HCH presented here showed a strong decreasing trend in concentrations up to levels below VR by a factor of 6. Dissolved TBT concentrations are in agreement with earlier reported trends. Nevertheless TBT concentrations in sediment still exceed the MTR by a factor of 15. Nevertheless, the TBT biospecific effects on Littorina littorina appeared to be small. Since the early nineties a general improvement in flounder health, in terms of ulcers and tumours, was noted for the Wadden sea, Eastern Scheldt and coastal zone. However, some of the highest incidences of flounder diseases appeared in 2002, weakening earlier reported downward trends. The quality assurance Programme of the Dutch Laboratories and details on detection limits, and participation in QUASIMEME exercises are given.