22 | New Scientist | 16 April 2022OceansSHOALS of breeding anchovies may
be stirring the ocean off the coast
of Spain. The finding suggests that
fish could play a bigger role in ocean
mixing than previously believed.
Bieito Fernández Castro at the
University of Southampton in the
UK and his colleagues measured
the speed of ocean currents off the
Galician coast, in north-west Spain,
for two weeks in July 2018.
The researchers initially planned
to study the effects of vertical ocean
mixing on marine life in various
parts of the ocean, but quickly
changed tack when they saw
a major unexplained rise in
turbulence in their first few nights
at the same spot. Ocean mixing is
largely thought to be controlled by
wind and tidal energy, but neither
factor could explain this night-time
rise, says Fernández Castro.The researchers moored their
vessel at the same spot for two
weeks and monitored turbulence
24 hours a day. They found that it
increased every night by a factor
of between 10 and 100. Using
an echo sounder, the researchers
discovered that anchovies were
gathering near the boat every night.
Investigating further and finding
anchovy eggs led the team to
conclude that the fish were
gathering there to reproduce
(Nature Geoscience, doi.org/hpr6).
“The possibility that biology
contributes to ocean mixing is
quite controversial,” says Fernández
Castro. “But we were able to
measure and quantify it in this
case. What we don’t know yet
is how important it is for overall
ocean circulation.”
Jason Arunn MurugesuAnchovies stirring up the
sea may alter ocean mixing
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News In brief
MODIFIED solar panels that work
at night generate enough power
to charge a phone, bypassing the
need to store energy in batteries.
In simple terms, solar electricity
is generated when the sun radiates
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At night, however, solar panels
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Stanford University in CaliforniaTechnologyand his colleagues modified an
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When pointed at a clear
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hpnw). This is just 0.04 per cent of
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can work at nightTUMBLE-DRYING clothes releases
microfibres, but switching your
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dryer sheet could cut this.
Microfibres (pictured) are tiny
strand-like particles that detach
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Neil Lant at consumer goods
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10 polyester T-shirts using various
brands of detergents, fabric
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They found that ordinary fabric
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cent (PLoS One, doi.org/hpnm).
While these products can reduce
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cut microfibre leak