A recent explosion of small phytoplankton is causing the Bosphorus Strait — a body of water that divides Europe and Asia — to turn turquoise.
Though this event may seem strange, scientists assure it is a normal reaction linked to plankton population spikes across the black sea. They also say the color will likely last for a while as the blooms continue to grow throughout June.
Scientists first captured the phenomenon through the the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA’s Terra satellite. The sudden change surprised many locals, who feared it was the result of pollution. However, officials quickly put down those rumors. Not only is the occurrence normal, but plankton are a good food source for anchovies that live in the region.
“This has nothing to do with pollution,” assured Ahmet Cemal Saydam, a professor at Hacettepe University, according to Tech Times.
Phytoplankton are microscopic floating organisms that use both sunlight and dissolved nutrients to create food. The species responsible for the recent event is known as Emiliania huxleyi. The reason they alter the water is that, like most phytoplankton in the region, they are plated with white calcium carbonate that reflects the sun. This causes them to give the water a milky appearance.
“When conditions are right, phytoplankton populations can grow explosively, a phenomenon known as a bloom,” explained NASA, according to NPR. “Blooms in the ocean may cover hundreds of square kilometers and are easily visible in satellite images. A bloom may last several weeks, but the life span of any individual phytoplankton is rarely more than a few days.”
While large blooms can help ecosystems, they also can lead to problems. If the spikes occur too frequently, they can cause water to lose oxygen, which then triggers die-offs of different species.
A bloom like the one in the straight occurred last year in New Jersey when phytoplankton turned coastal waters from the Long Beach Island coast to Cape May a greenish shade. Blooms also have triggered the greening of Arctic ice.