Page 28 - aruba-today-20180901

A28 SCIENCE
Saturday 1 September 2018
Telltale bits of DNA help track past and elusive wildlife

By EMILIANO RODRIGUEZ Danish geneticist Eske Will-
MEGA erslev, who pioneered
Associated Press the technique. He had
NEW YORK (AP) — On a been traveling to Siberia
scorching summer day, to sample permafrost. The
Mark Stoeckle threw a frozen soil was so cold that
bucket into the murky wa- he thought ancient ge-
ters of New York's East River netic material could have
to fill up three small plastic remained intact through-
bottles. out the years. In 2002, with
The biologist hopes the wa- a handful of permafrost
ter he collected contains samples the size of a sugar
the genetic trail of the riv- cube, he was able to iden-
er's diverse life including all tify the genetic material of
of its fish — and of course, bison, horses and many dif-
the occasional rat. ferent plants that lived hun-
"We've cleaned up the East dreds of thousands of years
River significantly, but we're ago. He also found the pre-
still dumping a lot of stuff," served DNA of mammoths.
said Stoeckle of Rockefeller Environmental DNA "helps
University. "This will give us a us reach the inaccessible,"
better idea of whether fish said Willerslev from the
are recovering or not." In this Sunday, Sept. 18, 2016 photo provided by Océanos Vivientes, marine biologist Ramón Bonfil Natural History Museum of
He doesn't have to catch submerges a bottle into the waters of the Chetumal Bay in Quintana Roo, Mexico. Denmark, adding that this
the slippery fish himself —a Associated Press approach will play a key
dangerous task given the role in scientists' quest to
river's rocky bottom and DNA floating in waterways For Sam Chew Chin, a fish to be a "muddy-boots and understand nature.
strong currents. He just or hiding in soil, which they ecologist at York College bloody-desk biologist." Examples of this are ap-
needs to look for the tiny call environmental DNA or in New York, the DNA sam- Studying fish meant cap- pearing in other fields,
bits of DNA they leave be- eDNA, promises to help in pling reminds him of child- turing them and eventu- where eDNA has changed
hind to track them. managing and protect- hood shows he loved such ally killing them. Now, he how researchers think
Animals lose hair, scales ing biodiversity. The tactic as Star Trek. searches for whales off of about conservation.
and feathers as they move. has become increasingly "Whenever they'd find a Long Island or fish in the When Colleen Kamoroff
They also discard skin cells popular within the past new planet, they would Hudson River by testing spent the summer collect-
and waste. All of these few years and has already scan it for life,'" he said. "De- water — an advance that ing water in 2015 from the
leave traces of genetic provided clues of ancient tecting environmental DNA has made his job faster and lakes in California's Sierra
material that can be de- mammoths in Siberia, early is kind of the closest we cheaper. Nevada, she saw a healthy
tected hours, weeks or warnings of frog die-offs in come to being able to do It wasn't always like that. group of native mountain
even millennia later. California and evidence of that. It's pretty neat." Nobody really cared about yellow-legged frogs hop-
Scientists say analyzing the elusive sawfish in Mexico. Chew Chin said he used eDNA a decade ago, said ping around.q

Researchers feed seaweed to

dairy cows to reduce emissions

DAVIS, Calif. (AP) — Univer- “I was extremely surprised University of California re-
sity of California research- when I saw the results,” searchers are studying
ers are feeding seaweed to said Ermias Kebreab, the whether feeding seaweed
dairy cows in an attempt to UC Davis animal scientist to dairy cows will reduce
make cattle more climate- who led the study. “I wasn’t their emissions of methane,
friendly. expecting it to be that dra- a potent greenhouse gas
UC Davis is studying wheth- matic with a small amount released by livestock. Early
er adding small amounts of seaweed.” Kebreab says results look promising, and
In this June 8, 2018 image taken from video, cows are milked at of seaweed to cattle feed his team plans to conduct more studies are planned.
a dairy farm at the University of California, Davis, in Davis, Calif., can help reduce their emis- a six-month study of a sea- (Aug. 31) Researchers
where researchers are feeding seaweed to dairy cows in a bid
to make cattle more climate-friendly. sions of methane, a potent weed-infused diet in beef worldwide have searched
Associated Press greenhouse gas that’s re- cattle starting in October. for ways to reduce cattle
leased when cattle burp, More studies will be need- emissions with various food
pass gas or make manure. ed to determine its safety additives such as garlic,
In a study this past spring, and efficacy, and sea- oregano, cinnamon and
researchers found meth- weed growers would have even curry — with mixed
ane emissions were re- to ramp up production to results. If successful, add-
duced by more than 30 make it an economical op- ing seaweed to cattle feed
percent in a dozen Holstein tion for farmers. Dairy farms could help California dairy
cows that ate the ocean and other livestock opera- farms comply with a state
algae, which was mixed tions are major sources of law requiring livestock op-
into their feed and sweet- methane, a heat-trapping erators to cut emissions by
ened with molasses to dis- gas many times more po- 40 percent from 2013 levels
guise the salty taste. tent than carbon dioxide. by 2030.q