Manta Rays are Safe in Indonesia. On February
21, Indonesia announced it would become the world's
largest manta ray sanctuary. The archipelago's 5.8
million square kilometers of ocean are protected from
manta fishing and export. That's because government
officials were persuaded by evidence that mantas are
worth more alive than dead -- a study published last
year in online journal PLoS One said a manta ray is
worth up to $1 million during its lifetime, thanks to
tourists who will pay to swim with them, but only
worth up to $500 when dead. Now conservation
groups are teaching fishermen about the value of
manta ray tourism, and more than 200 policemen have
been prepped to enforce the law.
A Common Chemical Kills Coral Reefs. Thanks
to subscriber Jonathan Scott (Waltham, MA) for alerting
us to research showing that a common chemical
used in many soaps, shampoos and cosmetics is killing
young coral reefs at concentrations commonly found
in the environment. The study, in this month's issue
of Ecotoxicology, found that benzophenone-2 (BP-2) is
toxic to coral reefs, causing increased rates of death and
bleaching. BP-2 is found in U.S. wastewater, and once
in the environment, can quickly kill juvenile corals at
even low concentrations. BP-2 is similar to oxybenzone,
the active ingredient in many sunscreens (although it's
not used in U.S. sunscreens), and it's considered an
emerging contaminant of concern by the EPA.
He Can't Swim with Them, But He'll Protect
Them. In last month's Flotsam, we listed an item about
Leonardo DiCaprio saying he was mentally scarred
after swimming too close to great whites during a cage
dive in South Africa. That didn't prevent him from
taking out his wallet to fund marine protection efforts.
Last month, he gave a $3 million grant to the nonprofit
Oceana. Spread over a three-year period, the grant will
support Oceana's work to advocate for responsible
fishing measures, including a ban on California drift gillnets, which often catch and kill the 'bycatch' of dolphins,
turtles, whales and other marine animals.
Coroner's Warning: Dump Your Weights. Emma
Carlyon, a coroner in Cornwall, England, warns all divers to
dump their weights when in trouble on the surface. This is
after investgating the 2010 death of experienced diver Clive
Robert Jones, who become separated from his buddy during
a dive on a Cornish reef and was spotted on the surface
waving for help. After a minute he slipped underwater and
fellow divers later found Jones, 60, lying on the sea bed
and still wearing all his weights. His computer showed he
ascended 100 feet in less than a minute. The safety inspector
who examined the weight belt said the Velcro surrounding
the weights was too strong. While she could find no evidence
why Jones had surfaced so quickly, Carlyon accepted
that the weight harness Jones was wearing had been difficult
to remove, and wrote in a statement, "I think it would
be appropriate to write to dive organizations and to the
manufacturers of this belt to highlight the difficulty, as highlighted
in his case, in removing the belt and the need for
divers to check they are able to release the belts."
Starfish Can See. Starfish use photoreceptors, lightsensitive
organs at the tips of their arms, to find their way
home if they stray from the reef. But scientists didn't know
whether they're actually real eyes or simply structures that
detect changes in light intensity. Resarcher Anders Garm at
the University of Copenhagen in Denmark solved the mystery.
He collected healthy starfish and removed the arm-tip
photoreceptors from a third. He made similar incisions on
another third but left the eyes intact; the remaining starfish
stayed untouched. He moved all starfish from their rocks
onto the sandy bottom -- where they would starve if they
didn't get back to the reef. Intact starfish promptly scuttled
back to the rocks. Eyeless starfish scuttled just as fast, but in
random directions. That shows they need the photoreceptors
to recognize and move towards the reef by forming an
image of it -- which means they can process visual information.
Garn thinks the visual task of navigating towards large
stationary objects was an important step in eye evolution,
meaning even humans' eyes evolved so we could find our
way home.