1. Status for the North Sea
Nutrients and Hazardous substances (Contaminants)
Martin M. Larsen
Presented by
Jonas K. Rømer
AU-DCE

2. Nutrient summary
All nutrients data was received on 16th September 2017
Data quality was checked and aggregated during spring 2018
Less than 152 datapoints was changed during QA procedure for nutrients (<0,2% of Nitrates)
<0 values observed for O2 (Swedish, indicating Sulfide) and Chlorofyll (0,4% of dataset, indicating fluorometer calibration problems)
Preparation for DIVA products
Overlap regions with Baltic Sea, Atlantic Ocean and Polar seas was sent to the regional leaders of these regions during summer 2018 for DIVA production
Probably we will extend the overlap for any future work – still problems in the North Sea – Baltic Sea (The Sound and Belt Sea areas around Eastern Denmark/Sweden)
MSFD marine regions should be used (currently an OSPAR division was used). (for boundaries between regions)
Outstanding problem: Is it the QA assured data set that is on the portal? (as pointed out by Kari, Magnus)
5/1/2019

3. Nutrient summary
Planned river products: Thames outlet, Weser and Elbe outlet. Major ones that have significant impact
5/1/2019

4. No of CDI’s in the North Sea dataset per nutrient
Tabel 11: Total number of CDIs for nutrients, Oxygen and Chlorophyll in the North Sea Region
Nb CDIs
Phosphate
Total Phosphorus
Nitrates
Nitrite
Nitrate+nitrite
Total
479,670
72,541
66,645
398,314
405,312
Ammonium
Total Nitrogen
Silicate
Oxygen
Chlorophyll
115,743
359,411
3,109,955
4,492,387
5/1/2019

5. Example Phosphate data coverage and time span
Very good geographical coverage for Phosphate but not always new data (north of UK particularly), the most active period was in the late 80ies and first half of the 90ies, then pretty steady until mid 2000, whereafter a decline in nutrient measurements begin to become evident. Maybe this is just lag of reporting data, but my feeling is that cruises in general are decreasing and ”other means of monitoring” or just cut backs are to be blamed.
5/1/2019

6. Phosphate QA check: TP vs Dissolved Phosphate
1. Very few data are below the line of TP=Dissolved Phosphate (DP), indicating that most samples have higher TP than DP (as expected).
The red square/cross marks an outlier, who’s quality flag have been edited to ”(probably) bad”.
2. The colorplots shows DP and TP vs salinity. Lower salinity is (off course) at the top of water column, but also high Phosphor numbers. Again, the red dot marks the ”probably bad” measurement.
5/1/2019

7. DIVA products – 6 year moving analysis, 1980 – 2017 Eutrophication
DIVA products created and uploaded for six variables: Phosphate, Silicate, Dissolved inorganic nitrogen, Chlorophyll-a, Dissolved oxygen saturation, Dissolved oxygen concentration.
Recently: Metadata, abstract and DOI assignment finished with guidance from Menashe.
Experiences from the process of creating the DIVA products
- Some script and configuration work and issues going from ten to six years periods
- When creating metadata, we unfortunately found that some netcdf files were missing obsid values
- Had to recreate products running with more allocated memory. In general difficult to work with the large data files.
Current status:
- Some corrections may be sent. Kari and Magnus, Baltic, has pointed out that some years of summer phosphate looks wrong, and not in line with their values. We are trying to look into it, but no cause found yet. Also some confusion about boundary used for data exchange vs DIVA cut to region.
5/1/2019

8. DIVA products – 6 year moving analysis, 1980 - 2017
MSFD marine regions
5/1/2019

9. DIVA products – 6 year moving analysis, 1980 - 2017
OSPAR marine regions, and red indicates boundary used for previous products
5/1/2019

10. Hazardous substances summary
All hazardous substance data was received on 27th September 2018
Problems with data import
Data quality was checked as min-max, and main task was harmonizing of the dataset
Overlap regions with Baltic Sea, Atlantic Ocean and Polar seas was sent to the regional leaders of these
Probably we will extend the overlap next time – still problems in the North Sea – Baltic Sea (The Sound and Belt Sea areas around Eastern Denmark/Sweden)
5/1/2019

11. Data harmonization 5/1/2019 filename Stations # params original
#params after harm.
# harmed params
Non harmonized
collection_sample_id 23
207
206
168
collection_minimumObservationDepth
370
257
147
131
Lipids, dryWt (%)
Mxlength
Sediment_depth_profiles(1)
2640
769
336
214
Depth, normalisersC xxx_sed63_D
(CPs, BDEs, PAHs)
Sediment_depth_profiles
(Danish sediment data)
158 10 8
TBT µmol/kg (wrong unit!)
Ocean_Depth_Profiles
(Biota data)
60597
4603
4098
1404
Normalisers, nutrients, many relevant species data!
Time_series
2642
791
745
672
Nutrients, pigments,
normalisers
Time_series_CDJ
3956
166
145
102
Nutrients, susp. Matter measurement
SUM
70386
6803
5687
2699
5/1/2019

12. Time trends and Ocean depth profiles (biota)
5/1/2019

13. Example data – Hg/Cd Mytilus
5/1/2019