Havsbränna

Havsbränna is a Swedish term that translates to "sea burn" or "sea fire." It refers to a phenomenon where certain types of algae, particularly dinoflagellates, bloom in coastal waters. These microscopic organisms, when present in large numbers, can cause the water to luminesce or glow, especially at night. This bioluminescence is a chemical reaction within the algae that produces light when disturbed.

The visual effect of havsbränna can be quite spectacular, with waves, boats, or even swimmers creating trails of blue or green light in the water. While often a beautiful natural display, dense blooms can sometimes have negative ecological consequences. Some species of dinoflagellates can produce toxins that harm marine life, leading to fish kills or other disruptions in the ecosystem. These toxic blooms are often referred to as harmful algal blooms or red tides, though havsbränna specifically highlights the bioluminescent aspect.

The occurrence of havsbränna is influenced by various environmental factors, including water temperature, nutrient levels, and salinity. Warmer temperatures and increased nutrient runoff from land can contribute to the conditions favorable for algal blooms. While the phenomenon is widespread in coastal areas globally, the term "havsbränna" is specific to Swedish and Scandinavian contexts. It is a natural occurrence that, under normal circumstances, is a harmless and awe-inspiring spectacle of nature.