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Get Lost in the Swirling Green Seas of a Massive Algae Bloom

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The summer of 2015 will probably be remembered as one of fire, drought, and hot, hot weather. But it’s also been a summer of frightfully voracious, microscopic life forms. From Lake Erie to the North Atlantic, tiny green algae are multiplying like crazy. And there’s no better way to appreciate the sheer immensity of these blooms than to take a look at the Baltic Sea, where swirling ocean currents are causing viridescent sea storms.

The image above, aptly dubbed “Eye of an Algal Storm,” was captured by the European Space Agency’s Sentinel-2A satellite over the middle of the Baltic Sea on August 7th. With a spatial resolution of just 10 meters, shimmering green ripples and waves are captured in stunning detail. In the top center of the image, you can even make out the wake of a ship as it slices through cyanobacteria-laden waters.


Here’s another, slightly more zoomed-out view of the algal bloom from the same day:


Algae blooms make striking pictures, but they also have a nasty tendency to produce toxic pollution and eat up all the oxygen in the water, choking out other marine life forms. That’s why we now have a 7,000 square mile dead zone in the Gulf of Mexico. There are a lot of things that can cause algal blooms to spread like wildfire, including warm waters, calm seas, and fertilizer pollution. (The first two are implicated in this summer’s Baltic bloom).

Meanwhile on this side of the Atlantic, algae fed by phosphorus-rich agricultural runoff are causing the Great Lakes to look unusually emerald. Scientists studying Lake Erie say it’s almost certain to be the worst bloom on record.

And if that wasn’t enough, a warm Pacific Ocean blob is feeding another massive algae bloom, one that runs the entire length of the west coast from Alaska to California. This bloom, composed mainly of pseudo-nitzschia algae, is particularly worrisome because it’s producing domoic acid, a potent neurotoxin that can make its way into mammals via shellfish. Fisheries in affected areas have been closed for the summer.


Sentinel-2A, which was launched into orbit on June 23rd as part of Europe’s new Copernicus environmental monitoring program, has only been active for a few weeks. Between Copernicus and NASA’s ever-growing fleet of Earth-observing satellites, our ability to study ecosystems from space has been increasing tremendously. Let’s just hope that our capacity to fix environmental problems begins to grow in step.

[ESA News | NASA]

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