COMPASS
BRIEFING
SCIENCE
OLD FISH KNOW THE TRICKS
A new theory suggests that catching
older fish may have dramatic impacts
on migratory patterns. The study,
published in the Journal of the Royal
Society Interface, implies that older
fish carry with them the school’s
collective memory, and that vital
migratory routes are lost when these
older members are fished out.
The implications are dramatic,
revealing that by targeting larger
individuals (common practice in
most fisheries), we are systematically
undermining essential migratory
patterns that lead schools to spawning
and feeding grounds. Once these
routes have been interrupted, and not
learned by succeeding generations,
they are ultimately lost forever.
Examples of these kinds of “lost
migrations” are already evident. The
Atlantic bluefin tuna used to journey
to the North and Norwegian Seas to
feed on herring, but, today, are no
longer found in these waters – an
absence which scientists are now
proposing may be due not only to
decreased populations, but also to
the interruption of the species’
collective memory.
It has been suggested that water
arrived on Earth via comets, long after
the planet was formed. But a new
study undertaken by a team at the
Woods Hole Oceanographic Institution
(WHOI) and published in the journal
Science is rolling back this critical date
significantly – it looks like water was
here all along.
“The study shows that Earth’s
water most likely accreted at the same
time as the rock. The planet formed as
a wet planet with water on the surface,”
said Horst Marschall, a geologist at
WHOI and coauthor of the paper.
While the findings don’t preclude
a late addition of water on Earth, it
shows that it wasn’t necessary since the
right amount and composition of water
was present at a very early stage.
“An implication of that is that
life on our planet could have started
to begin very early,” added WHOI
geologist and coauthor of the paper,
Sune Nielsen. “Knowing that water
came early to the inner solar system
also means that the other inner planets
could have been wet early and evolved
life before they became the harsh
environments they are today.” SDAA
ORIGIN OF EARTH’S
WATER DISCOVERED
The origin of Earth’s water,
essential for life on this planet, has
long been a subject of speculation,
research and debate amongst the
scientific community.
COMIC CORNER
Time to stop diving with our
heads in the sand...
FACTS AND FIGURES
85%
Over
SDAA
8
of the demand for
sustainable seafood is due
to consumer pressure
12%
Around
of Earth’s land is
protected, compared to
roughly 1% of the oceans
30 to
35%
of all critical marine habitats such as
seagrasses, mangroves and coral reefs are
estimated to have been destroyed