Bio-optics, satellite remote sensing and Baltic Sea ecosystems: Applications for monitoring and management
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Earth observation satellites cover large areas with frequent temporal repetition and provide us with new insight into ocean and coastal processes. Ocean colour measurements from satellite remote sensing are linked to the bio-optics, which refers to the light interactions with living organisms and dissolved and suspended constituents in the aquatic environment. Human pressures have changed the aquatic ecosystems, by, for example, the increased input of nutrient and organic matter leading to eutrophication. This thesis aims to study and develop the link between bio-optical data and the remote sensing method to the monitoring and management of the Baltic Sea. The results are applied to the European Union’s Water Directives, and the Baltic Sea Action Plan from the Helsinki commission. In paper I indicators for eutrophication, chlorophyll-a concentration and Secchi depth were evaluated as a link to remote sensing observations. Chlorophyll-a measurements from an operational satellite service (paper I) were compared to conventional ship-based monitoring in paper II and showed high correlations to the in situ data. The results in paper I, II and IV show that the use of remote sensing can improve both the spatial and temporal monitoring of water quality. The number of observations increased when also using satellite data, thus facilitating the assessment of the ecological and environmental status within the European Union’s water directives. The spatial patterns make it possible to study the changes of e.g. algae blooms and terrestrial input on larger scales. Furthermore, the water quality products from satellites can offer a more holistic and easily accessible view of the information to decision makers and end-users. In paper III variable relationships between in situ bio-optical parameters, such as coloured dissolved organic matter (CDOM), dissolved organic carbon, salinity and Secchi depth, were found in different parts of the Baltic Sea. In paper IV an in situ empirical model to retrieve suspended particulate matter (SPM) from turbidity was developed and applied to remote sensing data. The use of Secchi depth as an indicator for eutrophication linked to the concentrations of chlorophyll-a and SPM and CDOM absorption was investigated in paper V. The variations in Secchi depth were affected differently by the mentioned parameters in the different regions. Therefore, one must also consider those when evaluating changes in Secchi depth and for setting target levels for water bodies. This thesis shows good examples on the benefits of incorporating bio-optical and remote sensing data to a higher extent within monitoring and management of the Baltic Sea.
Place, publisher, year, edition, pages
Stockholm: Department of Ecology, Environment and Plant Sciences, Stockholm University , 2015. , 59 p.
Bio-optics, Remote sensing, MERIS, Eutrophication, Baltic Sea, Monitoring, Management, WFD, MSFD, HELCOM, Chlorophyll-a, Secchi depth, Coloured Dissolved Organic Matter, Suspended Particulate Matter
Research subject Marine Ecology
IdentifiersURN: urn:nbn:se:su:diva-119578ISBN: 978-91-7649-219-2OAI: oai:DiVA.org:su-119578DiVA: diva2:849120
2015-10-02, William-Olssonsalen, Geovetenskapens hus, Svante Arrhenius väg 14, Stockholm, 13:00 (English)
Markager, Stiig, Professor
Kratzer, Susanne, Associate professorWalve, Jakob, PhDPhilipson, Petra, PhD
FunderSwedish National Space Board, Dnr. 165/11EU, European Research Council, SPICOSA 36992Nordic Council of Ministers, 80106 & 42041EU, FP7, Seventh Framework Programme, WaterS 251527Baltic Ecosystem Adaptive Management (BEAM), 4315403Ecosystem dynamics in the Baltic Sea in a changing climate perspective - ECOCHANGE, 4315403Swedish Environmental Protection Agency, WATERS
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.2015-09-102015-08-172015-09-29Bibliographically approved
List of papers