The spatial distribution and particle size of some inorganic nitrogen, sulphur and chlorine species over the North Sea

1992 ◽  
Vol 26 (9) ◽  
pp. 1689-1699 ◽  
Author(s):  
C.J. Ottley ◽  
Roy M. Harrison
Keyword(s):  
Particle Size ◽  
Spatial Distribution ◽  
North Sea ◽  
Inorganic Nitrogen ◽  
The North ◽  
The North Sea

scholarly journals Long-term hydrological and phytoplankton monitoring (1992–2007) of three potentially eutrophic systems in the eastern English Channel and the Southern Bight of the North Sea

2011 ◽  
Vol 68 (10) ◽  
pp. 2029-2043 ◽  
Author(s):  
Alain Lefebvre ◽  
Natacha Guiselin ◽  
Frederique Barbet ◽  
Felipe L. Artigas
Keyword(s):  
North Sea ◽  
Inorganic Nitrogen ◽  
Regional Scale ◽  
Nutrient Concentrations ◽  
English Channel ◽  
Southern Bight ◽  
The North ◽  
The North Sea ◽  
Phytoplankton Monitoring

Abstract Lefebvre, A., Guiselin, N., Barbet, F., and Artigas, F. L. 2011. Long-term hydrological and phytoplankton monitoring (1992–2007) of three potentially eutrophic systems in the eastern English Channel and the Southern Bight of the North Sea. – ICES Journal of Marine Science, 68: 2029–2043. The spatial and main temporal variations in nutrient concentrations and phytoplankton abundance were investigated between 1992 and 2007 in the eastern English Channel and the Southern Bight of the North Sea, zones of consistent presence of Phaeocystis globosa and diatom blooms. Silicate and phosphate were the main nutrients potentially limiting phytoplankton growth, but the dynamics of the limitation seemingly differ between sites. Phosphate concentration showed a clear monotonic decreasing trend, whereas dissolved inorganic nitrogen and silicate trends were more complex. Nitrate was rarely or never a limiting factor. Results highlight three main periods with a Phaeocystis- or diatom-dominated system in the 1990s, and a more complex pattern in the 2000s. The composition of the phytoplanktonic community is described and an attempt made to establish a link between the community and its environment in terms of variability, shifts, and trends. The effects of larger- vs. regional-scale controlling factors are also discussed.

Sediment-water fluxes of inorganic nitrogen compounds along the transport route of organic matter in the North Sea

Ophelia ◽  
1995 ◽  
Vol 41 (1) ◽  
pp. 173-197 ◽  
Author(s):  
Lutz Lohse ◽  
Johannes F. P Malschaert ◽  
Caroline P. Slomp ◽  
Willem Helder ◽  
Wim van Raaphorst
Keyword(s):  
Organic Matter ◽  
North Sea ◽  
Inorganic Nitrogen ◽  
Nitrogen Compounds ◽  
Water Fluxes ◽  
The North ◽  
The North Sea

scholarly journals Consistency of thresholds for eutrophication assessments, examples and recommendations

2021 ◽  
Vol 193 (10) ◽  
Author(s):  
D. Topcu ◽  
U. Brockmann
Keyword(s):  
Chlorophyll A ◽  
North Sea ◽  
Coastal Waters ◽  
Inorganic Nitrogen ◽  
Mixing Processes ◽  
The North ◽  
The North Sea ◽  
International Harmonisation ◽  
Nitrogen Nutrients ◽  
Mixing Diagrams

AbstractInternational harmonisation of management goals for eutrophication processes in coastal waters, requiring reduction of discharges and depositions of nutrients and organic matter, needs coordinated assessments and measures. This is especially necessary in open areas, connected by currents and mixing processes with trans-boundary exchanges. Management goals, defined nationally as local thresholds for nutrients and chlorophyll-a, had been applied recently (2006–2014) within international eutrophication assessments in the North Sea (OSPAR) and Baltic Sea (HELCOM). Consistency of thresholds for nitrogen nutrients and chlorophyll-a concentrations is tested by mixing diagrams and correlations between nitrogen nutrients (total and inorganic nitrogen) and chlorophyll-a. Results indicate mean consistent relations, but single deviations as in the continental coastal water of the North Sea surpassed means by a factor up to 5 for chlorophyll-a in relation to inorganic nitrogen. Thresholds differed across national borders significantly. Correlations of thresholds and assed data reflect the degree of regional deviations by comparison. Consistency of regionally applied thresholds can be achieved stepwise, by application of regionally correlated means, by adaptation to mixing and parameter relations, and finally by relations of thresholds to natural background concentrations. By this, consistency of international assessments can be improved generally, allowing coordinated management of open coastal waters.

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