Press Release In April, Sentinel-1A Satellite Detected 15 Oil Slicks in the Northern Caspian Sea
The global environmental movement Save the Caspian Sea expresses serious concern over the results of the latest stage of radar-based pollution monitoring of the Caspian Sea, conducted by the international environmental project Transparent World on the Caspian (https://transparentworld.tech/).
In April alone, the Sentinel-1A satellite detected 15 oil-contaminated slicks covering a total area of approximately 32 square kilometers, which is equivalent to the size of 5,000 football fields.
According to satellite imagery, the Kazakh sector of the Caspian Sea was the most polluted, with five recorded spills covering 17.6 km². This was followed by the Russian sector (eight incidents totaling 13.4 km²) and the Azerbaijani sector (two incidents, 1 km²).
The largest detected spill, measuring 4.9 km², was found on April 24 in the Kazakh sector. The same area also showed extensive zones of natural oil seepage, exceeding 11 km² in total.
According to the monitoring team, oil and petroleum pollution remains one of the most pressing environmental challenges facing the Caspian Sea. Pollution sources include oil and gas extraction and transportation in the waters of Russia, Kazakhstan, Azerbaijan, Iran, and Turkmenistan, as well as runoff from the Volga River and other tributaries. A significant portion of the pollution is primarily anthropogenic in origin.
"The situation requires constant attention. Even localized spills can have a cumulative effect that poses a serious threat to the Caspian ecosystem," note members of the Transparent World on the Caspian project.
The monitoring was conducted using radar imagery from the Sentinel-1A satellite and the CLASS.PRO analytical platform, based on methodologies developed by the P. P. Shirshov Institute of Oceanology of the Russian Academy of Sciences. The study covered the northern and parts of the central Caspian Sea and was carried out in cooperation with companies Lorette LLC, Raimet Scientific and Production Foundation, and Ctrl2GO. All research results are publicly available on the portal: https://transparentworld.tech/.
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The global environmental movement Save the Caspian Sea expresses serious concern over the results of the latest stage of radar-based pollution monitoring of the Caspian Sea, conducted by the international environmental project Transparent World on the Caspian (https://transparentworld.tech/).
In April alone, the Sentinel-1A satellite detected 15 oil-contaminated slicks covering a total area of approximately 32 square kilometers, which is equivalent to the size of 5,000 football fields.
According to satellite imagery, the Kazakh sector of the Caspian Sea was the most polluted, with five recorded spills covering 17.6 km². This was followed by the Russian sector (eight incidents totaling 13.4 km²) and the Azerbaijani sector (two incidents, 1 km²).
The largest detected spill, measuring 4.9 km², was found on April 24 in the Kazakh sector. The same area also showed extensive zones of natural oil seepage, exceeding 11 km² in total.
According to the monitoring team, oil and petroleum pollution remains one of the most pressing environmental challenges facing the Caspian Sea. Pollution sources include oil and gas extraction and transportation in the waters of Russia, Kazakhstan, Azerbaijan, Iran, and Turkmenistan, as well as runoff from the Volga River and other tributaries. A significant portion of the pollution is primarily anthropogenic in origin.
"The situation requires constant attention. Even localized spills can have a cumulative effect that poses a serious threat to the Caspian ecosystem," note members of the Transparent World on the Caspian project.
The monitoring was conducted using radar imagery from the Sentinel-1A satellite and the CLASS.PRO analytical platform, based on methodologies developed by the P. P. Shirshov Institute of Oceanology of the Russian Academy of Sciences. The study covered the northern and parts of the central Caspian Sea and was carried out in cooperation with companies Lorette LLC, Raimet Scientific and Production Foundation, and Ctrl2GO. All research results are publicly available on the portal: https://transparentworld.tech/.
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Fig. 1. Ship-related oil spill in the Kazakh sector, on Sentinel-1A SAR image from 24.04.2025. © ESA
Fig. 2. Natural oil seepage in the Kazakh sector, on Sentinel-1A SAR image from 04.04.2025. © ESA
Fig. 3. Natural oil seepage in the Kazakh sector, on Sentinel-1A SAR image from 23.04.2025. © ESA
