14 November 2020 | New Scientist | 17AN ICEBERG the size of Cyprus is
heading towards South Georgia,
posing a major threat to the remote
Atlantic island’s globally important
penguin and seal colonies.
Icebergs breaking off from
Antarctica often fragment in the
South Atlantic. But the sheer scale
of this 158-kilometre-long and
48-kilometre-wide chunk of ice,
named A68a (near-centre in this
image), is unusual, say researchers
following it by satellite.
It could arrive at South Georgia
within a month, potentially blocking
access to offshore feeding grounds
for the island’s macaroni, gentoo,
king and chinstrap penguins, as well
as fur, leopard and elephant seals.
This would make it difficult for
the animals to feed their young.
Organisms on the seabed near
the island would also be pulverised
by the giant block of ice, potentially
releasing their vast stores of carbon
into the atmosphere. ❚
Environment
MOST sea turtles, whales and fish
may have plastic in their bodies.
To determine the prevalence of
various forms and colours of this
material in marine animals, Marga
Rivas at the University of Almería
in Spain and her team analysed
data from 112 studies published
in the past decade.
These looked for microplastics –
fragments less than 5 millimetres
in size – and larger macroplastics
in marine specimens globally.
Of the studies, 80 examined the
gastrointestinal tracts of animals
to see what they had ingested. The
others also looked at wider animal
tissues to identify plastics that end
up in other parts of the body.
After examining all of the data,
Rivas and her team concluded
that 66 per cent of sea turtles
have white-coloured macro and
microplastics in their systems,
while 55 per cent have a distinct
class of plastic called microfibres,
which are shed by some fabrics.
The high prevalence of white
plastic in turtles was unsurprising,
says Rivas, given that plastic of this
colour, particularly larger pieces,
may resemble jellyfish, a large
part of the animals’ diets.
Microfibres were also present in
80 per cent of cetaceans – a group
of aquatic mammals that includes
whales and dolphins – and white
macro and microplastics in 38 per
cent of them.
The researchers also concludedthat clear fibre microplastics are
probably the most common form
of this waste that is ingested by
large marine animals globally.
Rivas and her colleagues also
discovered that the animals
with the highest rates of plastic
ingestion were those in the
Mediterranean and the north-
east Indian Ocean (Global
Change Biology, doi.org/fg8d).“The Mediterranean is the most
contaminated sea in the world, so
we expected to find these results,”
says Rivas.
Marine plastic pollution has
increased roughly 10-fold since
1980, and Rivas says the problem
is exacerbated by inadequate
water treatment systems.
In parts of India and the south-
east Mediterranean, wastewater
isn’t adequately treated or
recycled, she says. This means
that microfibres shed by fabrics
in washing machines, and larger
pieces of rubbish, enter the sea.
“It’s possible to introduce
management strategies to control
these huge threats,” says Rivas. ❚Pollution
Most whales may have ingested plastic
Adam Vaughan
Humpback
whales are
among marine
life that is
ingesting
plasticIceberg on collision course
Huge iceberg may hit a South Atlantic island and harm wildlife
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