scholarly journals Impact of introduced juvenile mussel cultures on the pelagic ecosystem of the western Wadden Sea, The Netherlands

2016 ◽  
Vol 8 ◽  
pp. 553-566 ◽  
Author(s):  
P Jacobs ◽  
R Riegman ◽  
J van der Meer
Keyword(s):  
The Netherlands ◽  
Wadden Sea ◽  
Pelagic Ecosystem ◽  
Juvenile Mussel

scholarly journals Regulating Subsidence and its uncertainty in the Dutch Wadden Sea

2020 ◽  
Vol 382 ◽  
pp. 63-70
Author(s):  
Johannes A. de Waal ◽  
Mathijs W. Schouten
Keyword(s):  
Natural Gas ◽  
The Netherlands ◽  
Land Subsidence ◽  
Wadden Sea ◽  
Gas Production ◽  
Reservoir Rock ◽  
Proper Management ◽  
Subsidence Rate ◽  
Non Linear ◽  
Regulatory Approach

Abstract. At the start of gas production its effects on land subsidence are not certain. There are uncertainties in mechanisms, models and parameters. Examples are non-linear deformation of reservoir rock, fault transmissibility, behaviour of overlaying salt and aquifer activity. Looking back at historical cases in the Netherlands, a factor two or three difference between initial prediction and final outcome is quite common. As the Dutch regulator, SSM is tasked with assuring proper management by operators of the risks associated with land subsidence from natural gas production in The Netherlands. Large initial uncertainties can only be tolerated if operators can demonstrate that timely actions can still be taken when predefined subsidence limits are at risk of being exceeded now or in the future. The applied regulatory approach is illustrated by the case history of gas production induced subsidence in the Dutch Wadden Sea area. This environmentally highly sensitive UNESCO World Heritage Site is a natural gas province. Extensive legal, technical and organisational frameworks are in place to prevent damage to its natural values. Initial uncertainties in the predicted subsidence (rate) were later exacerbated by the detection of strong non-linear effects in the observed subsidence behaviour, leading to new concerns. It was realised that – depending on the underlying physical cause(s) – there will be a different impact on future subsidence. To assure proper management of the additional uncertainty by the operator, several improvements in the regulatory approach have been implemented. Possible underlying mechanisms had to be studied in depth and improved data analysis techniques were requested to narrow down uncertainties as time progresses. The approach involves intensified field monitoring, scenario's covering the full range of uncertainties and a particle filter approach to handle uncertainties in predictions and measurements. Spatial-temporal double differences, production data and the full covariance matrix are used to confront scenario predictions against measurements and to assess their relative probability. The regulator is actively involved in assuring this integrated control loop of predictions, monitoring, updating, mitigation measures and the closing of knowledge gaps. The regulator involvement is supported in the Mining law and by appropriate conditions in the production plan assent. With the approach it can be confidently assured that subsidence (rate) will remain within the allowed range.

scholarly journals CMOS-based Image Cytometry for Detection of Phytoplankton in Ballast Water

2017 ◽  
Author(s):  
M Jofre ◽  
J M Perez ◽  
P Martinez ◽  
Z Moubarak ◽  
C Hurth ◽  
...  
Keyword(s):  
The Netherlands ◽  
Ballast Water ◽  
Wadden Sea ◽  
Limit Of Detection ◽  
Water Environment ◽  
Image Cytometry ◽  
Marine Water ◽  
Pam Fluorometry ◽  
Ballast Water Treatment Systems ◽  
Fresh Water Environment

An image cytometer (CYT) for the analysis of phytoplankton in fresh and marine water environments is introduced. A linear quantification of the number of cells over several orders of magnitude of concentrations was observed using cultures of Tetraselmis and Nannochloropsis measured by autofluorescence of the chlorophyll in a laboratory environment. The functionality of the system outside the laboratory was analysed by phytoplankton quantification of samples taken from marine water environment (Dutch Wadden Sea, The Netherlands) and fresh water environment (Lake Ijssel, The Netherlands). The CYT was also employed to study the effects of two ballast water treatment systems (BWTS), based on chlorine electrolysis and UV sterilisation by determining the vitality of the phytoplankton. In order to ensure the detection limit, a large volume (1l) of samples was collected and concentrated to 3 ml using CelltrapTM filters. The results were compared to benchmarked flow cytometer and PAM Fluorometry at Marine Eco-Analytics (MEA-NL). The image cytometer reached a 10 cells/ml limit of detection (LoD) with an accuracy between 0.7 and 0.5 log, and a correlation of 88.29% in quantification and 96.21% in vitality, when compared to benchmarked monitoring techniques.

scholarly journals Are Medieval Mya arenaria (Mollusca; Bivalvia) in the Netherlands also clams before Columbus?

2016 ◽  
Vol 96 (1) ◽  
pp. 9-16 ◽  
Author(s):  
K. Essink ◽  
A.P. Oost ◽  
H.J. Streurman ◽  
J. Van der Plicht
Keyword(s):  
North America ◽  
The Netherlands ◽  
Baltic Sea ◽  
Wadden Sea ◽  
Bivalve Mollusc ◽  
Mya Arenaria ◽  
Marine Bivalve ◽  
Southern Baltic Sea ◽  
Coastal Marine ◽  
Northwest Europe

AbstractDuring the Pleistocene, the coastal marine bivalve mollusc Mya arenaria became extinct in northwest Europe. The species remained present in North America. Datings of Mya shells found in northern Denmark and the southern Baltic Sea suggest that repopulation of northwest European coasts already occurred before Columbus’ discovery of America (1492), possibly facilitated by Viking (Norse) settlers at Greenland and northeast North America. In this paper we report on findings of M. arenaria at five locations in the coastal landscape of the Netherlands: polders reclaimed from the Wadden Sea and the former estuaries of Oer-IJ and Old Rhine. The shells from four of these locations also date before 1492 AD.

scholarly journals Mitigating and Adapting Agriculture of Coastal Areas in the Netherlands Wadden Sea Region to Increasing Salinization

2021 ◽  
pp. 231-258
Author(s):  
Mindert de Vries ◽  
Jouke Velstra ◽  
Johan Medenblik ◽  
Joca Jansen ◽  
Linda Smit ◽  
...  
Keyword(s):  
The Netherlands ◽  
Wadden Sea ◽  
Coastal Areas
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