- The Guardian Saturday 30 April 2022
(^48) World
Fish on drugs Cocktail of medications
is ‘contaminating ocean food chain’
Salomé Gómez-Upegui
N
icknamed “grey
ghosts” for their
lustrous silver
scales, remarkable
stealth and speed,
bonefi sh can swim
at up to 40mph. This species,
protected by catch-and-release
laws in the US, is revered by anglers
around the world, many of whom
visit Florida to seek the elusive fi sh.
But evidence points to a steep
drop in bonefi sh numbers in south
Florida. Populations have fallen
more than 50% over four decades,
researchers estimate.
Dr Jennifer Rehage , a fi sh
ecologist and associate professor
at Florida International University
(FIU), has spoken to many anglers
about the fi sh’s disappearance from
Florida’s seagrass fl ats: “They’ve
said to me: ‘I’ve fi shed [bonefi sh]
all my life and I can’t fi nd them.run-off , but human and livestock
wastewater is one of the main
causes – especially what humans
send down the toilet.
While specifi c health eff ects
on marine life are not yet fully
understood, there is evidence of
multiple negative results. “[It] can
provoke several consequences,
mainly on the behaviour of fi sh,
but it can also aff ect their ability
to reproduce and their endocrine
system,” says Elena Fabbri , a
professor at the department
of biological, geological and
environmental sciences at Bologna
University in Italy.
In 2013, scientists from Umeå
University in Sweden – which
partnered with FIU on the bonefi sh
study – found that wild perch were
less fearful and more antisocial
when exposed to anti-anxiety
medications, which could aff ect
feeding and breeding.
A 2016 study by the same
university found salmon exposed
to this medication swam faster andI haven’t seen a bonefi sh in fi ve
years, and it’s freaking me out.’”
For the past three years, Rehage
has been leading a study to fi nd
out why, and has discovered
something that may help explain
it: pharmaceuticals. Of the 93
bonefi sh her team sampled, all
tested positive for at least one
pharmaceutical, including heart
medications, opioids, antifungals
and antidepressants, according to
their results , published in February.
In 56% of fi sh, researchers
detected pharmaceutical quantities
at levels “above which we expect
negative eff ects”. One bonefi sh
in Key West tested positive for 17
pharmaceuticals – eight of them
antidepressants that were up to 300
times above the human therapeutic
level. Pharmaceutical exposure
in south Florida’s bonefi sh was
“widespread and concerning ”.
The researchers also studied
125 animals that bonefi sh prey on,
including shrimp, crabs and small
fi sh. Each contained an average of11 pharmaceutical contaminants,
indicating that the contamination
is not limited to bonefi sh.
While more is known about
the impacts of pharmaceutical
pollution in freshwater species,
marine impacts have been far less
studied. There is still not enough
information to directly link
bonefi sh decline with drugs, but
“the potential for pharmaceuticals
to be a problem is formidable and
concerning”, Rehage says.
T he average American has
about 12 prescriptions a year.
Pharmaceuticals reach the water
in various ways , including through
manufacturing and rainwater‘The potential for
drugs to be a problem
is formidable’Dr Jennifer Rehage
Florida ecologist