In Mudanya distroct of Bursa, Türkiye, an impressive ‘algae bloom’ illuminated the sea with blue light at midnight as a result of the prolific emergence of single-celled organisms. The Marmara Sea’s Mudanya coast witnessed blue flashes due to the proliferation of plankton, visible only under a microscope. The algae bloom altered the sea’s color, particularly noticeable in Mudanya and Güzelyalı, causing a light blue hue. This natural phenomenon captivated onlookers, with some enjoying the spectacle and others capturing the moments. Termed ‘Red Tide’ or ‘Algae Bloom,’ this event results from increased algae populations due to nutrient density, causing water to appear red or brown, and sometimes causing discomfort. The occurrence is described as local, seasonal, and typically observed in shallow coastal waters, inland seas, bays, lakes, and areas near river mouths.