Recently, Bonaire experienced yet another influx of the brown seaweed, Sargassum, which motivated STINAPA and many volunteers to head out to Lagun several mornings last week to remove it from sensitive beach and mangrove areas. Sargassum fluitans and Sargassum natans are the two species of brown algae that make up these floating mats, which are also the main species in the Sargasso Sea, affectionately called “The Golden Floating Rainforest”.
In the open ocean, these floating mats are extremely diverse, providing important habitat for over 250 species of fish and invertebrates, many of which are not found anywhere else. As you may know, young sea turtles often spend their tender years finding refuge and a plentiful food supply in these floating seaweed mats.
Unfortunately for us, climate change has brought warmer temperatures (which increases algal growth rates) and possibly stronger currents/shifting currents which, combined with more and more land-based nutrients flowing into our oceans, are thought to be the reason why we are seeing more and more massive ‘strandings’ of these floating seaweed mats. Once the algae hits the shore, it either washes up, or accumulates, sinks and rots. When it rots, all of the oxygen gets used up and hydrogen sulfide forms, both of which cause massive die-offs of marine life. We saw dead baby turtles, lobsters and fish, among other sea life, presumably victims to the decay of the seaweed.
Something of interest about this Sargassum is that it is believe to be formed, not in the Sargasso Sea in the northern Atlantic, but in the equatorial regions of the Atlantic (the North Equatorial Recirculation Region). The next time we have large quantities of algae on our shores and you feel like lending a hand, please check the STINAPA Facebook page for information on volunteer activities. STINAPA would like to thank all of the volunteers that helped out last week – the creatures living in the bay at Lagun have a much better chance at surviving this!