Trichodesmium bloom near the Great Barrier Reef Today’s Image of the Day from NASA Earth Observatory features a bloom of Trichodesmium near the Great Barrier Reef off northeast Australia.
Trichodesmium blooms start off with a yellowish-brown color when the bloom is healthy, turn green as it begins to decay, and turn white after the pigments decay.
The cyanobacteria plays an important role in the ocean because it supplies large quantities of nitrogen for marine ecosystems, accounting for about 60 to 80 percent of nitrogen fixation in the ocean.
This image was captured on September 1, 2019 by the Operational Land Imager on Landsat 8.A large part of the reef is protected by the Great Barrier Reef Marine Park, which helps to limit the impact of human use, such as fishing and tourism. Other environmental pressures on the reef and its ecosystem include runoff, climate change accompanied by mass coral bleaching, dumping of dredging sludge and cyclic population outbreaks of the crown-of-thorns starfish. According to a study published in October 2012 by the Proceedings of the National Academy of Sciences, the reef has lost more than half its coral cover since 1985, a finding reaffirmed by a 2020 study which found over half of the reef’s coral cover to have been lost between 1995 and 2017, with the effects of a widespread 2020 bleaching event not yet quantified
Image Credit: NASA Earth Observatory