A team of researchers in the United States and Spain has solved one of the main riddles about red tide blooms by uncovering the specific mechanism that triggers phytoplankton to release their powerful toxins into the environment. They presented their research in February at the 56th Annual Meeting of the Biophysical Society. The scientists discovered that phytoplankton release their toxin-loaded gels when exposed to sunlight, particularly the blue portion of the spectrum. Pedro Verdugo, a University of Washington researcher said, “We do not know why phytoplankton respond to blue light, but it might be associated with the fact that blue light penetrates deeper in seawater.” “Often, plants and animals release toxins as a defense mechanism. Whether this is the case in phytoplankton remains speculative. However, blue light stimulation implies that these cells must have a photoreceptor most likely associated with the cell structures known as chloroplasts, which are responsible for photosynthesis. This is in fact one of the riddles we’ll tackle next.”
