The World's Forgotten Fishes - 8

INTRODUCTION

1%

OF AQUATIC
HABITAT IS
FRESHWATER
Figure 1: Approximately 1% of the earth's
surface area is freshwater and 71% is marine,
yet over half of known fish species are
found in freshwater.

Freshwater fishes are amazing for so
many reasons. From the spectacular
ornamental species like the angelfish*
that are amongst the world's most
popular pets to the beluga sturgeon that
historically grew as large as a great white
shark 2, and the gilded catfish that migrate
over 10,000km3, freshwater fishes have
adapted to life in a dizzying variety of
ways. They have evolved to fill every
available niche in almost every freshwater
ecosystem from clear alpine streams
to sediment rich tropical rivers, from
shallow ponds to the world's great lakes,
from flooded forests to waters flowing
through underground caves. And many
migrate between ecosystems - and even
thousands of kilometres out to sea.
They have swum through our societies
since the beginning of human history.
They have fed us for millennia and are
critical for the food and nutrition security,
livelihoods and cultures of hundreds
of millions of people across the globe.
Meanwhile, the challenge of catching
iconic or even common species - from
salmon to mahseer, tigerfish to carp -
inspires millions of anglers to spend
billions of dollars each year on the vast
recreational fishing industry. And when
it comes to both angling and keeping
aquariums, just being around fishes is
good for our health by reducing stress and
lowering our blood pressure.
Freshwater fishes play important
roles within our ecosystems and serve
as indicators of the health of those
ecosystems. They are an aquatic version
The World's Forgotten Fishes page 8

51%

OF KNOWN FISH
SPECIES ARE FOUND
IN FRESHWATER
of the canary in the coalmine for the
world's rivers, lakes and wetlands. If our
freshwater ecosystems deteriorate to the
point where they can't support a healthy
population of fish, we can be sure they
won't be fit for humans either.
Yet, in many senses, these are the
world's forgotten fishes. Today, nearly
a third of freshwater fish species are
threatened with extinction due to a
devastating combination of threats from
damming rivers to draining wetlands,
abstracting too much water for irrigation
to releasing too much untreated waste,
from unsustainable and damaging fishing
practises to introductions of invasive
non-native species - and, of course, the
escalating impacts of climate change.
Since the 1970s, migratory freshwater
fish populations have declined by an
estimated 76 per cent on average4, while
populations of freshwater mega-fishes
(fish heavier than 30kg) have declined by
an even more catastrophic 94 per cent5.
But very few people have any inkling of
the speed at which freshwater fishes are
being lost - or what the consequences
will be if we don't reverse this disastrous
trend.
Despite their importance and the
magnitude of the threats they face,
freshwater fishes, and freshwater
biodiversity in general, remain an
afterthought for policymakers and the
public at large. Rivers continue to be
valued primarily as water pipes for cities,
industry, agriculture and power, ignoring
their many 'hidden' benefits, such as the
freshwater fisheries they sustain. Very
rarely, for example, are the full values
of freshwater fisheries factored into
decisions about hydropower dams or
dredging for navigation or sand mining.

This can't continue. Humanity can't
afford to lose any more of the world's
forgotten fishes or the freshwater
ecosystems they inhabit. Rivers, lakes
and wetlands are our life support systems
and the extraordinary diversity of fishes
within them are essential to their health
and ours. To secure our own future, we
must act now.
The good news is that we know what
needs to be done: the world must
implement an Emergency Recovery Plan
for freshwater biodiversity6. Developed
by scientists and freshwater experts from
across the world, this practical, sciencebased plan incorporates six pillars -
each of which has been implemented in
different parts of the world:
1. Let rivers flow more naturally;
2. Improve water quality in freshwater
ecosystems;
3. Protect and restore critical habitats;
4. End overfishing and unsustainable
sand mining in rivers and lakes;
* Scientific names for all species in the text are on page 47
The World's Forgotten Fishes

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