Assessing the cleanup efforts at the historically polluted site in the Port of Liepaja, Karosta Channel.
Master thesis
Permanent lenke
https://hdl.handle.net/11250/3137395Utgivelsesdato
2024Metadata
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Sammendrag
The presence of persistent contaminants in the sediments, such as heavy metals and hydrocarbons, can have long-lasting negative effects on marine ecosystems, resulting in harming both wildlife and humanity. It is critical to rehabilitate the impacted habitats and prevent future contamination for our own good. Such an example is the Port of Liepāja from Latvia, where high levels of pollutants were identified more than two decades ago. Since then many efforts have been made to improve the ecological status of the channel, following a complex strategy of multiple cleaning procedures to ameliorate the negative impact over the Baltic Sea and to exclude the Port of Liepāja from the Red List of ”collapsing biotopes” (HELCOM 2013).
The current study aimed to assess the environmental hazard of persistent contaminants and trace the effects of the environmental measures undertaken over time in the Karosta Channel - Liepaja, Latvia. The most recent and consistent dredging activities had the purpose of removing the majority of the remaining polluted sediments from the channel. This created an ideal moment for evaluating the immediate environmental impact of the dredging as such and calculating the rate of ecosystems' regeneration in the near future. Moreover, by analyzing the content of hydrocarbons and heavy metals in the residual sediments, the study provided more information on how successful the ecological cleanup was.
The critical evaluation of the methods applied within this project provided a different perspective over the theorized remediation procedures, thus developing knowledge in this aspect. The results of the study revealed that hydrocarbons and heavy metal pollutants cannot be easily removed from coastal marine habitats. Dredging activities, in the absence of the complementary procedure of “capping”, increased the levels of detected pollutants in the remaining sediments and surface water. By disturbing the old deposits of contaminated sediments, the cleaning procedure had a negative impact on the habitat, worsening the overall pollution status. In the end, it was concluded that such actions provide the opportunity for a better ecological state in the near future if certain measures are taken.
This project will contribute to the existing knowledge of cleaning techniques in the coastal zones, emphasizing sediments and other particulate-bound contaminants, by applying new technologies and learned methods.