This dataset is a compilation of en-route thermo-salinometry data recorded by the RV A962 Belgica. Data are grouped per campaign from 1993 until 2021. Data are measured by a Sea-Bird thermo-salinometry sensor installed in the vessel Scientific Seawater circuit (constant depth).

An analytical method was developed for the trace quantification of oxygenated polycyclic aromatic hydrocarbons (oxyPAHs) in mussels. Compounds included were naphthalene-1-ol, 9H-fluoren-9-one, anthracene-9,10-dione, 7H-benz[de]anthracene-7-one, naphtacene-5,12-dione and benzo[a]anthracene-7,12-dione. Pyrene-1-carboxaldehyde was applied as an internal standard. Sample extraction by pressurized liquid extraction was followed by clean up on silica, separation by high performance liquid chromatography and quantitative measurement by mass spectrometry with atmospheric pressure chemical ionisation. The method was validated by the analysis of spiked mussel samples, resulting in trueness values of 90-124% and measurement uncertainties of 6-49%, except for naphthalene-1-ol. Quantification limits varied from 0.25 ng.g-1 to 10.7 ng.g-1. The developed analytical oxyPAH method was applied on mussel samples from groynes and quaysides along the Belgian coastline and oxyPAH data were compared to PAH concentration data. The sum of 14 US EPA priority PAHs reached maxima at the eastern side of the Belgian coastal zone, with on average 202 ng.g-1 for quayside Zeebrugge and 38.4 ng.g-1 for groyne Knokke mussels. Anthracene-9,10-dione concentrations reached maxima of 19.1 ng.g-1 mussels at the most industrialized quayside of Zeebrugge. For other oxyPAHs, no clear relationship could be made with direct PAH emissions. Concentrations of anthracene-9,10-dione and 9H-fluoren-9-one were found to exceed corresponding parent PAH concentrations.

The chemical status of five dredged spoil disposal sites in the Belgian Part of the North Sea, near the ports of Ostend and Nieuwpoort, is evaluated. A linear mixed-effect model was applied to PCB, PAH and heavy metal data from 2005-2014. No decrease in PCB concentrations was found, with even an increase at two disposal sites. Hg/AL ratios increased with 62% at one disposal site (BR&WS2) from 2005-2006 to 2013-2014. Cu and Zn concentrations increased at two disposal sites. Additional harbour sampling suggests that the latter is possibly linked to antifouling paints. Based on OSPAR environmental assessment criteria, the current chemical status of the sites suggests no chronic effect of dredged spoil disposal. However, increasing time trend data for PCB, Hg, Cu and Zn demonstrate the importance of monitoring to identify adverse trends.