The World's Forgotten Fishes - 39

* Sucking rivers dry: Poor
management has resulted in far too
much water being abstracted from
river systems, primarily for irrigation.
Agriculture uses around 70 per cent
of all water abstracted globally69 -
and this is likely to increase since the
world's demand for food is projected
to grow by 50 per cent by 205070.
* Dredging up too many fish and
too much sand: Critical natural
resources in freshwater ecosystems
are being unsustainably plundered
in many areas. Overfishing is
threatening many species populations,
especially when combined with
destructive fishing methods, which
also threaten the health of the
environment. Meanwhile, unregulated
and illegal sand mining alters
the structure of rivers and deltas,
destroying critical habitat, including
fish spawning habitat, putting the
survival of freshwater - and coastal -
fishes at risk.

IUCN RED LIST STATUS

* Wildlife crime: While most
people believe wildlife crime is all
about elephant ivory, tiger bones and
rhino horns, poaching and the illegal
wildlife trade are grave threats to
many freshwater fishes, including
sturgeons for illegal wild caviar,
European eels, the giants of the
Mekong, stingrays and some
endangered ornamental species.
* Species invasions: The intentional
and accidental spread of invasive
non-native species and diseases are
becoming more common, unbalancing
freshwater ecosystems and directly
threatening native species.
* Our warming world: Climate
change is already making its presence
felt, melting glaciers that feed rivers
and altering peak river flow events
in high mountain regions, changing
weather patterns and increasing water
temperatures. Freshwater fishes are
particularly vulnerable to climate
change71. Many are like polar bears:
they have nowhere to go when their
part of the world changes.
To compound these issues, freshwater
fishes are contending with other
threats to biodiversity that we're only
just beginning to understand, such as
noise, light and microplastics pollution
to name a few72 . There is no silver
bullet for these myriad threats, but
there are tried and tested solutions.
It's time to scale them up.

Number of species

Extinct

80

Extinct in the Wild

10

Critically Endangered (presumed extinct)

583 (115)

Endangered

870

Vulnerable

966

Near Threatened

511

Least Concern

5332

Data Deficient

264

Total assessed

© Faunagua / Paul van Damme

* Flood of pollutants: From
untreated sewage to agricultural
run-off, industrial wastewater and
mercury from gold mining, pollutants
are pouring into rivers, lakes and
wetlands, poisoning fishes and
fuelling toxic algae blooms. 300400 million tonnes of pollution are
dumped into freshwater ecosystems
every year67, and over 80 per cent of
all wastewater is flushed untreated
back into nature68.

10516

GILDED CATFISH: RECORDBREAKER AT RISK
These silver-gold South American
catfish can grow to 2m, but not
until they've survived the longest
freshwater migration of all fishes,
which starts when they spawn high
in the foothills of the Andes at the
headwaters of the Amazon. The
young fish drift and swim 5,800km
down to the mouth of the river,
where they live for two or three
years before tackling the mammoth
return leg. Rising waters after the
rainy season are the signal for them
to head back upstream: one year
later they're back in the mountains,
ready to breed. But the gilded
catfish's astonishing migration
can only take place when there
are healthy, free-flowing rivers to
support it. Hydropower dams are
increasingly blocking their way,
while deforestation and mining
are threatening crucial spawning
areas from Colombia to Bolivia. As
well as being an important source
of food for indigenous people and
local communities along the river,
this so-called 'goliath catfish' is an
indicator of freshwater ecosystem
health - and its future survival is in
doubt. It's an alarming sign for the
whole river system.

Fig 7. Summary of IUCN status of freshwater fishes73

The World's Forgotten Fishes page 39
The World's Forgotten Fishes

Table of Contents for the Digital Edition of The World's Forgotten Fishes
