Science - USA (2020-09-04)

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SCIENCE sciencemag.org 4 SEPTEMBER 2020 • VOL 369 ISSUE 6508 1155

CREDITS: (GRAPHIC) C. BICKEL/


SCIENCE


; (DATA) JIM HUDSON/HELLTH.COM


NEWS | IN DEPTH

As the stickleback grew numerous, they
became a formidable foe: They eat juvenile
pike and perch. In earlier studies, co-author
Ulf Bergström from the Swedish Univer-
sity of Agricultural Sciences and colleagues
found both species in the stomachs of stick-
lebacks. Eklöf, Bergström, and their col-
leagues caught and analyzed fish in 32 bays
and confirmed that where stickleback were
abundant, juvenile pike and perch were
scarce. Thus, as stickleback became more
plentiful in more places, pike and perch had
even less chance to recover.
This is not the first time that scientists
have documented a predator-prey reversal.
For example, large populations of herring in
the North Sea likely drove down numbers of
cod, their predator, by feasting on tiny cod
juveniles. But such connections have been
difficult to document. “This result seems re-
markably clear,” deYoung says.
The work also stands out because it
documents such a widespread and last-
ing ecological shift, adds Steve Carpenter,
a limnologist at the University of Wiscon-
sin, Madison. More typically, research-
ers have observed such shifts in a single
location, often a lake, showing how domi-
nance swings back and forth between two
species as temperature changes or fishing
becomes more intense, he says. The new
results “show that regime shifts can spread
among connected habitats and transform
an entire coastline rather rapidly.”
The stickleback surge is triggering other
ecosystem impacts. The fish eat snails
and crustaceans that previously kept
green algae in check, favoring the return
of algal blooms that had been declining
in these waters thanks to pollution con-
trol measures.
The work “clearly shows that the [dis-
appearance] of larger predators can cause
cascading effects all the way down to algae,
and that these changes can unfold over vast
spatial scales like falling dominoes,” says
Boris Worm, a marine biologist at Dalhou-
sie University. Worm worked in the Baltic
Sea as a Ph.D. student, and he mourns the
change, calling it “a slow-motion disaster
through the Baltic Sea.”
Eklöf and others are now considering
how to bring back pike and perch, per-
haps by locally fishing out stickleback or
stocking bays with juvenile pike and perch
too big for stickleback to eat. For now, the
lesson is clear. “The world is changing at
a very fast rate and ecosystems are shift-
ing, most times to less desirable states,”
says Julián Torres Dowdall, an evolution-
ary biologist at the University of Konstanz.
How politicians and managers respond to
the result of this study “is important to
our planet.” j

Cannabis research data reveals


a focus on harms of the drug


Funding for therapies grows slowly, new analysis finds


P O L I C Y

F


or research funders, marijuana is still
more vice than virtue. A new analysis
of cannabis research funding in the
United States, Canada, and the United
Kingdom has found that $1.56 billion
was directed to the topic between 2000
and 2018—with about half of the money
spent on understanding the potential harms
of the recreational drug. Just over $1 bil-
lion came from the biggest funder, the U.S.
National Institute on Drug Abuse (NIDA),
which doled out more money for research on
cannabis misuse and its negative effects than
for studies of cannabis and cannabis-derived
chemicals as a therapeutic drug. Total Ca-
nadian and U.K. spending was far lower, at
$32 million and $40 million, respectively;
U.K. funding also emphasized harms.
The data confirm “word on the street”
that government grants go to research that
focuses on harms, says Daniela Vergara, who
studies cannabis genomics at the University
of Colorado, Boulder. Still, research on the
medical potential of cannabis is growing
alongside overall cannabis research funding,
which rose from about $30 million in 2000 to
more than $143 million in 2018.
NIDA’s traditional focus is on addic-
tion and the adverse effects of drugs,
a spokesperson says. However, recently,
the agency has begun to explore the thera-
peutic potential of cannabinoids to treat

addiction, the spokesperson adds.
The analysis is based on data assembled by
Jim Hudson, a medical research consultant
who collected publicly available grant data
from 50 funding agencies and charities. He
classified the grants into categories based
on keywords. It’s the first attempt to analyze
cannabis grant data from a wide range of
sources, says Lee Hannah, a cannabis policy
researcher at Wright State University.
The analysis, posted last week on Hud-
son’s website, hints at the legal hurdles to the
research. In 2018, the $34 million spent on
therapeutics went mostly to research on can-
nabinoids—chemicals in cannabis—rather
than the cannabis plant itself. Vergara says
practicality is one reason: It’s often easier for
researchers to work with these isolated com-
pounds. But it’s also hard to get permission to
use the whole marijuana plant. The only legal
U.S. producer of research cannabis is the Uni-
versity of Mississippi, which grows cannabis
that is less potent than recreational pot.
The limited funding for therapeutic re-
search is part of a vicious circle, says Daniel
Mallinson, a cannabis policy researcher at
Pennsylvania State University, Harrisburg.
Research is restricted because the U.S. Drug
Enforcement Administration considers mari-
juana to have high potential for abuse and
does not see evidence for medical benefits.
But the evidence needed to show medical
benefits is hard to get because the research is
restricted, Mallinson says. j

By Cathleen O’Grady

10

20

30

40

50

60

70

US$ (millions)

0
2000 2005 2010 2015 2020

Attitudes, regulations, and markets

Cannabis therapeutics
Endocannabinoid system**
Cannabinoid therapeutics

Harms*

*Science’s harm category includes: eHects of cannabis; fetal or infant exposure;
use determinants; tolerance and withdrawal; prevention; and addiction treatments.

** Includes research on the body's cannabinoid receptors
and natural endocannabinoids that bind to them

Higher purposes
In 2018, research on the potential harms of cannabis received
about twice as much funding as research on cannabis and
cannabinoid therapeutics, according to an analysis of grants
from 50 public agency and charity funders.

Published by AAAS
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