Faculté des Sciences
Faculté des Sciences

Eutrophication assessment of the Southern North Sea using multi-satellite datasets

Martin, Samuel ULiège
Promotor(s) : Alvera Azcarate, Aida ULiège ; Van der Zande, Dimitry
Date of defense : 6-Sep-2021 • Permalink :
Title : Eutrophication assessment of the Southern North Sea using multi-satellite datasets
Translated title : [fr] Évaluation de l'eutrophisation du sud de la mer du Nord à l'aide de données multi-satellitaires
Author : Martin, Samuel ULiège
Date of defense  : 6-Sep-2021
Advisor(s) : Alvera Azcarate, Aida ULiège
Van der Zande, Dimitry 
Committee's member(s) : Hubert, Aurelia ULiège
Barth, Alexander ULiège
Capet, Arthur ULiège
Language : English
Number of pages : 66
Keywords : [en] Eutrophication
[en] Satellite remote sensing
[en] North Sea
[en] Southern North Sea
[en] Phytoplankton
Discipline(s) : Life sciences > Aquatic sciences & oceanology
Life sciences > Environmental sciences & ecology
Funders : Royal Belgian Institute of Natural Sciences (RBINS)
Research unit : GeoHydrodynamics & Environment Research (GHER)
Target public : Researchers
Professionals of domain
General public
Institution(s) : Université de Liège, Liège, Belgique
Degree: Master en océanographie, à finalité approfondie
Faculty: Master thesis of the Faculté des Sciences


[en] The North Sea (NS) is a highly productive semi-enclosed shelf sea of the Atlantic Ocean
located in the northern Europe. The southern North Sea (SNS), which is shallow and very well
mixed, has long suffered from eutrophication problems. As a result, various policy measures have been taken by the NS surrounding countries (OSPAR Convention) with the aim of achieving good environmental status (GES) of the NS by 2020. The use of satellite remote sensing is a coherent method of data acquisition and provides information with generally much greater spatial and temporal coverage than in-situ data, which provide very localized information in space and time.
Satellite remote sensing therefore offers an effective method to address long-term changes at
the scale of an entire basin, such as the SNS. The main aim of this master thesis was to use
high-level satellite gap-free products to assess the evolution of the eutrophication status and the
phytoplankton dynamics of SNS over a period from 1998 to 2017. Our analyses showed a strong gradient of chlorophyll (CHL, a proxy for phytoplankton biomass) from coastal areas (higher CHL) to offshore areas (lower CHL). At the scale of the SNS domain, CHL increased between 1998 - 2004, stagnated thereafter, until 2014, when it started to decrease, probably as a consequence of the reduction of river-bone nutrient inputs. Our analyses also showed that the suspended particular matter (SPM) increased over the period by 0.042 mg/L.year. In addition, sea surface temperature (SST) also increased by 0.021°C/year in the SNS, which is positively correlated to the North Atlantic Oscillation over our period. Another convincing result is that we observed a phenological shift of about 1 month in the onset date of phytoplankton blooms. While it is difficult to identify a factor responsible for the observed phenological shift, it has been observed that the climate regime of the SNS changed during late 1990s. We therefore assume that this phenological shift is due to a change in planktonic communities associated with the rise in temperature as well as the de-eutrophication trend occurring in the SNS, which could have favored the emergence of winter diatom blooms.




  • Martin, Samuel ULiège Université de Liège > Master en océanogra., à fin.


Committee's member(s)

  • Hubert, Aurelia ULiège Université de Liège - ULiège > Département de géographie > Géomorphologie et Géologie du Quaternaire
    ORBi View his publications on ORBi
  • Barth, Alexander ULiège Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > GeoHydrodynamics and Environment Research (GHER)
    ORBi View his publications on ORBi
  • Capet, Arthur ULiège Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > MAST (Modeling for Aquatic Systems)
    ORBi View his publications on ORBi
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  • Total number of downloads 47

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