The
ocean has always glowed.
اضافة اعلان
The
Greeks and
Romans knew of luminous sea creatures as well as
the more general phenomenon of seawater that can light up in bluish-green
colors.
Charles Darwin, as he sailed near South America on a dark night
aboard the HMS Beagle, encountered luminescent waves. He called it “a wonderful
and most beautiful spectacle.” As far as the eye could see, he added, “the
crest of every wave was bright” — so much so that the “livid flames” lit the
sky.
Now, scientists report that ocean bioluminescence can be so
intense and massive in scale that satellites orbiting 500 miles high can see
glowing mats of microorganisms as they materialize in the seas. Last month in
the journal Scientific Reports, eight investigators told of finding a luminous
patch south of Java in 2019 that grew to be larger than the combined areas of
Vermont, New Hampshire, Massachusetts, Rhode Island and Connecticut.
“It was an epiphany,” said Steven D. Miller, lead author on the
bioluminescence study and a specialist in satellite observations at Colorado
State University. When a hidden wonder of nature comes to light, he added, “it
captures your imagination.”
The scientists said the close examination of images gathered
between December 2012 and March 2021 from a pair of satellites let them
identify a dozen extremely large events — approximately one every eight months.
Even the smallest was a hundred times larger than Manhattan.
The imagery is opening a new window on the world’s oceans,
scientists say, and promises to aid the tracking and study of the glowing seas,
whose origins are poorly understood.
Kenneth H. Nealson, a pioneer of bioluminescence research at the
University of Southern California, called the discovery “a big step toward
being able to understand” how an enduring mystery of the sea “actually comes to
be.”
The new paper noted that the large concentrations of living
lights have long “eluded rigorous scientific inquiry, and thus little is known
about their composition, formation mechanism, and role within the marine
ecosystem.”
Sea bioluminescence is often associated with gruesome creatures
of the inky deep. One iconic illuminator is the anglerfish, which dangles
bright lures in front of needlelike teeth. In contrast, the luminous seas
appear to originate when many trillions of tiny bacteria light up in unison.
Nealson, who was not involved in the satellite research, and
colleagues reported in 1970 that dilute suspensions of a particular type of
bacteria emit no gleam. If allowed to multiply, however, the microbes can
suddenly light up as if a switch were thrown. Scientists now theorize that the
glittering masses of bacteria lure fish, whose guts provide nourishing
habitats.
Miller’s trail of discovery began nearly two decades ago when a
lunchtime chat raised the question of whether sea bioluminescence might be
visible from space. While working at the US Naval Research Laboratory in
Monterey, California, in 2004, he began examining imagery from a weather
satellite. Soon, he spotted in the northwestern Indian Ocean what turned out to
be a glowing patch that was nearly the size of Connecticut.
The blurry area was barely visible, but Miller and his colleagues
grew quite excited, because they knew that a new generation of satellite
sensors would soon provide much greater sensitivity and sharpness. The improved
sensors debuted on a pair of satellites launched by the National Oceanic and
Atmospheric Administration in 2011 and 2017.
The sensitive detectors proved adept — at least on dark nights —
at capturing glimmers of light from the seas and provided the imagery for the
current report.
A surprise, Miller said, is that the events turn out to persist
for long periods. For instance, the large patch off Java in 2019 lasted for at
least 45 nights. That raises the possibility that a rapid response team of
oceanographers might have enough time to reach the patches and take samples for
detailed studies.
To date, Miller said, no team has succeeded. He added that
television companies that make nature documentaries have shown interest in
using the satellite detections to track down and film the gleaming seas.
Peter Herring, a British marine biologist known for his work on
deep bioluminescence, called the satellite work important because, after ages
of uncertainty, it raised the prospect of finally coming up with hard evidence
of what powers the luminous whorls.
The discovery, he added, “is a large splash and will have significant
ripples.”
Read more
Lifestyle
.jpg)
.jpg)
