Do urea-based fertilizers serve as a “food source” for Karenia brevis?
Nitrogen undergoes several modes of transformation. Any N source could be considered as a food source for Karenia brevis, either directly or indirectly. There have been dozens of theories involving suspected nutrient delivery mechanisms for K. brevis. Scientists stress that these mechanisms are not mutually exclusive and that no single source can account for all the nutrients required to sustain a major bloom. Aside from the land-based nutrient sources, there are a number of atmospheric and oceanic sources that are receiving increased attention. Upwellings of deep, nutrient-enriched water along the continental shelf are viewed as playing a potential role in initiation of offshore blooms. A second significant source of nutrients may be trichodesmium, a cyanobacteria found throughout the world’s oceans. Trichodesmium can provide significant nutrients to K. brevis through the process known as nitrogen fixation. With adequate supplies of iron, trichodesmium can fix N from the atmosphere an
