Mystery of brightness in the 400 -year ocean may be close to the end

For over 400 years, sailors report a mysterious phenomenon in which the ocean seems to shine to where the view reaches.

“The sea, from horizon to horizon in all directions, acquired a phosphorescent shine … The moon had just settled and the whole sea was several shades lighter than the sky,” wrote J. Brunskill, official aboard the SS Ixion ship, which sailed through the Arabia Sea in 1967.

Almost 10 years later, another crew, aboard the ship MV Westmorland, experienced a similar event in the same region. According to Captain PW Price, the ship crossed a “large area of ​​bioluminescence.”

“The sea… it shone in an intense and bright green. So bright, in fact, that it was not possible to distinguish the waves or the movement of the sea – everything seemed a perfectly flat surface,” he wrote in a 1976 letter.

These events, nicknamed “milky seas” by sailors who were fortunate to witness them, have been notoriously difficult to study due to rarity and the fact that they occur in remote ocean regions, where few humans are present to observe them.

Now scientists seeking to investigate these peculiar phenomena more deeply are one step closer to predicting when and where these mysterious exhibitions of bioluminescence will occur.

Justin Hudson, a doctoral student at the Colorado State University’s atmospheric science department, compiled more than 400 known reports of “milky seas”-including Brunskill and Price’s-to create a new database that could, in the future, help researchers to position a scientific vessel at the site of one of these events, according to a study published in the magazine *Earth and Space Science *.

“My hope is that with this database more people can start studying the ‘milky seas’ and unraveling this mystery that has existed for centuries,” said Hudson, the main author of the new research.

He added that more in -depth studies on the “milky seas” can help answer many of the questions that still remain about the phenomenon, how they happen and what they can mean for marine life.

“Sucich seas can be a sign of something like a very good and healthy ecosystem. They can be a sign of an imbalance ecosystem – and we just don’t know,” he said.

“And as we can predict when and where they will happen, we can start answering these questions about where this phenomenon fits all our global and interconnected terrestrial system.”

Bioluminescent Bacteria

Observers often describe the “milky seas” as similar, in color, to the stars that shine in the dark and are glued to the ceiling of children’s rooms.

The brightness emitted by this phenomenon has already been considered, by sailors, strong enough to allow reading – a striking contrast with the typical ocean darkness when there is no sun or moonlight.

These events, which can last months, extend to up to 100,000 square kilometers, and the largest have already been detected from the space, according to the study.

Although scientists do not yet know exactly why this rare brightness occurs, the most accepted hypothesis is that it is a byproduct of the high concentration of bioluminescent microscopic bacteria called Vibro Harveyi.

This theory is based on a casual meeting in 1985, when a research vessel collected and analyzed a water sample during a “milky sea” event.

“But other than that, the conditions that lead to the formation of the phenomenon and how it causes the whole ocean to shine in this way are still widely unknown,” said Dr. Steven Miller, study co -author and professor at Colorado State University atmospheric science department.

Miller, who has been studying the phenomenon for decades, was the main author of a survey published in 2021 that revealed that the largest “milky seas” can be detected by satellites.

After compiling all known records of “milky seas” sightings – including historical reports of sailors and satellite data – the study authors identified some trends related to these mysterious events at sea: the “milky seas” appear mainly in the sea of ​​Arabia and in the waters of Southeast Asian, and can be influenced by certain global climate phenomena, such as the Dipolo of the Indian Ocean and the southern-niño-enlation, Hudson explained.

The regions where these phenomena occur more often tend to record ocean resurgence – when cold and nutrient rich waters from the depths of the ocean, rise to the surface driven by strong winds.

Hudson estimates that in these regions, there is about a “milky sea” event per year.

“They are conducive areas for a lot of biological activity,” said Hudson. “But there are many places on Earth with these same characteristics. So what really makes these regions special is still a big unknown.”

The role of “milky seas” in the ecosystem

The “milky seas” are different from the most common bioluminescent events in the ocean, caused by a type of phytoplankton known as dinoflagellate.

These organisms emit a bluish shine when they are disturbed – for example, when fish swim nearly or when the waves break on the coast – unlike the constant brightness observed in the “milky sea” events.

While phytoplankton flashes as a defense mechanism, the researchers believe that the bacteria of the “milky seas” shine to attract fish-that, when consuming them, allow them to thrive in the digestive tract of these animals, Miller, who is also director of the Cooperative Institute for Atmosphere Research (CIRA), of Colorado State University.

Like many other scientists who study bioluminescence, Miller expects one day witness this mysterious phenomenon personally.

Dr. Edith Widder, oceanographer and marine biologist who did not participate in the study, shares the same desire.

“I spent my career by watching and measuring bioluminescence in the ocean. I’ve seen views of amazing lights, but I’ve never seen a milky sea. And I really want to see,” Widder said in an email. “By gathering this database, the authors bring us even closer to the possibility of predicting where and when a ‘milky sea’ can occur.”

Widder, who is also a CEO and senior scientist at the Ocean Research & Conservation Association, wonders about the effects of this bioluminescent event on other marine life – especially in the creatures that hide in dark depths during the day and rise to the surface only in the dark to feed.

“Light is a critical factor in the distribution and behavior of animals in the ocean … What happens to this daily hide-and-hide game when the animals that need to hide are illuminated by all this bioluminescence? What is the impact on the carbon cycle? This is a natural experiment that has the potential to reveal a lot about the functioning of life in the ocean,” he added.

There have been previous attempts to compile databases on events of “milky seas”, but all ended up getting lost over time.

With the new database, this “redefines the starting point for us, with regard to our knowledge and awareness of where these events are taking place in the world and over time,” said Miller.

During these mysterious bioluminescent events in the ocean, “the bacterial population is responding in such a dramatic way, and in a way that we had not really anticipated as possible,” added Miller.

Among the many unanswered questions that remain: scientists do not know how climate change affects the occurrence of these luminous events and how it can impact the ecosystem, he noted.

“We need to understand how this process is working… Because, among many other things, bacteria and phytoplankton are associated with the base of the ocean food chain – all species and fish of higher orders depend on this food chain to exist. And changes in this food chain, based on changes in the circulation of our planet, are things we need to understand.”

This content was originally published in a brightness mystery in the 400 -year ocean may be close to the end on CNN Brazil.

Source: CNN Brasil