This eye-catching satellite image reveals organic material swirling in the Gulf of Gdańsk, Poland, a part of the Baltic Sea. Captured by the European Space Agency’s Sentinel-2A satellite on May 16, 2018, the photo highlights large slicks of unknown composition. But recent research has uncovered their surprising origin.
Scientists first noticed these slicks in 2000. They appear as transparent films on the ocean surface, often resembling algae blooms that wind and currents push around. However, unlike typical blooms, which are easy to spot, these slicks often show up during May and June, puzzling researchers about their source.
At one point, some thought they might be “sea snot,” a slimy substance produced by plankton. However, this theory didn’t stick since locals had never reported such outbreaks.
In a 2023 study, researchers finally unraveled the mystery: the slicks are primarily made of tree pollen. This finding aligns with the fact that Poland’s forests, dominated by pine trees, cover one-third of the country. Over 60% of these forests consist of the Scots pine (Pinus sylvestris).
Back in 2015, scientists detected traces of pollen on the Baltic Sea. Still, they didn’t realize then how significant this phenomenon could be. The latest study indicates that from 2000 to 2001, similar slicks appeared 14 times, coinciding with the pollen season.
Research Leader Chuanmin Hu from the University of South Florida noted, “Tracking pollen aggregation can provide vital data for fisheries studies.” Increased pollen levels could reshape marine ecosystems globally, especially as climate change intensifies. A 2021 study found that pollen levels in North America rose by 21% between 1990 and 2018, with pollen seasons extending by about 20 days. This is largely due to rising atmospheric carbon dioxide levels.
Understanding this connection can lead to new insights in environmental science. As pollen continues to reach the seas, it opens up discussions about its role in ocean health and fishing industries, showcasing how land and sea are more interconnected than we might think.