Netherlands National Monitoring of Heavy Metals in the Ems-Dollard Region (1976-)

Data set information

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Data holding centreRijkswaterstaat Central Information Services
CountryNetherlands  Netherlands
ProjectNational Chemical Monitoring Programme(MON*CHEMIE)
Time period1976-present
Geographical area

Ems-Dollard. The boundary between Eastern Wadden Sea and the Ems-Dollard estuary lies West from the Huibertsgat.


Colloidal metal concentrations in the water column; Dissolved metal concentrations in the water column; Inorganic chemical composition of sediment or rocks; Metal concentrations in biota


Particulates samplers; unconsolidated sediment corers; centrifuges; sieves and filters; inductively-coupled plasma atomic emission spectroscopes; spectrophotometers


MON*CHEMIE is a part of the Monitoring programme of the National Water Systems (in Dutch : Monitoring Waterstaatkundige Toestand des Lands; MWTL) The primary goal of the MWTL programme is to provide physical, chemical and biological information in relation to long term developments. So the focal point for the monitoring programme is based on trend detection. Another aim is to check the compliance to national and international assessment criteria. The Dutch marine and brackish waters are dived into areas. In field GEOGRAPHIC COVERAGE the area is mentioned. In MON*CHEMIE chemical parameters are determined in surface water, suspended matter, sediment and biota. The starting date mentioned is not necessarily the same for every parameter or location, this can differ from one parameter or location to another. Depending on the parameter and the location most samples are collected on a weekly, monthly or 3 monthly base. The given date is the first year data is available of one or more locations. During the given period more or less locations can be sampled due to changes in the national monitoring programme. Sampling and analysing the samples are carried out by Standard Operating Procedures (SOP's). The concentration of heavy metals are increased by human activities. Metals are not broken down and are absorbed by sediment for a long time. Metals are measured in various ecosystems: - Surface water: The samples are taken by diving pump. Until 1995 for all metals the total and the dissolved metal concentration in water is measured. From 1996 only dissolved metal is measured. - Suspended matter: In suspended matter the metals Cd, Cr, Cu, Hg, Ni, Pb, Zn and As are measured. The samples are taken by centrifuge. – Sediment: In sediment the metals Cd, Cr, Cu, Hg, Ni, Pb, Zn and As are measured. The samples are taken by boxcorer. In the sediment programme samples are taken every three years. – Biota: Yearly a number of locations are sampled for analyses in biota. For Flounder 25 specimen are collected (divided over 5 classes) and analysed individually. For analyses in mussels a large number of specimens are collected and pooled samples of 5 length classes are analysed. Dab is collected and analysed in pooled samples. In biota the following analysis are carried out: Dab and Flounder muscle: Hg; Flounder liver: Cd; Dab liver: Cd, Cu. Hg, Pb, Zn; Mussel soft body: Cd, Cr, Cu, Hg, Ni, Pb, Zn, As. For the actual planning:

OriginatorsRijkswaterstaat Water, Traffic and Environment
Data web site
OrganisationRijkswaterstaat Central Information Services
ContactNot supplied (Service Desk Data)

Rijkswaterstaat Central Information Services
Derde Werelddreef 1

2622 HA

Telephone+31 (0)15 275 77 00
Facsimile+31 15 275 75 76
Collating centreNational Oceanographic Data Committee
Local identifier20001044
Global identifier2910
Last revised2010-11-22