Fish Under Fire - Threats to Madagascar's Freshwater Diversity.
In the past 200 years, none of Madagascar's known mammal species have gone extinct.
In that same time, Madagascar has lost at least 6 kinds of native fishes, with 11
species so critically endangered that if current trends continue, they will become
extinct in the next decade. Fish and other animals living in freshwater habitats face a
large number of threats. Because river systems are interconnected, even animals living in
a stream running through a national park may be threatened by events upstream.
In this activity, you'll learn about some of the threats
to Madagascar's freshwater diversity as you swim up a
river. Though the river is imaginary, the threats are
real! As you try to swim upstream to lay your eggs,
you'll be faced with some of the many challenges
Madagascar's fish face.
Imaginary River System with a choice of fishes :
-
Fish A - This species is tolerant of many threats, but like most
freshwater fish it needs streams that flow year-round. Poor land
management and unwise water use can dry up streams and decimate the
aquatic creatures that depend on them. (Real Life example: Pachypanchax
sakarmayi died when the streams it lived went from permanent to
intermittent).
- Fish B - Hardy but delicious, this fish can
survive under a variety of conditions but is especially desirable as a
source of food and income. (Real Life example: Paretroplus sp.) -
overfished w/ gill nets.
- Fish C - This fish can't compete with
introduced species that are better at finding food and occupying nest
spaces. (Real Life Example: Pychochromoides itasy - the introduction of
Black Bass had a huge effect on its populations).
- Fish D -
This fish needs clear water, and can't survive when bad agricultural and
industrial practices cause rivers to turn murky with silt. (Real Life
Example: Betodia marojejy).
Eat Vanilla and Save Madagascar Fish!
Vanilla comes from an orchid that
likes to grow in the shade, so growers usually leave
trees standing - clearing only the underbrush - when
they plant vanilla. These trees help to stabilize
the soil and keep watercourses through Vanilla
orchards running clear - making them better places
for native fish to live and breed. The US is the
main importer of Malagasy vanilla, so one of the
best things you can do for threatened fish is to eat
that vanilla ice cream!
WCS - Helping
Protect Madagascar's Freshwater Habitats.
Because
rivers run through parks, the animals and plants
that live in them can often be threatened by what
happens up or down steam. When WCS helped support
the foundation of Masoala National Park in
Northeastern Madagascar, planners set the borders to
include entire river basins in order to help
conserve freshwater habitats.
Friend of Fish, Dr. Paul Loiselle
Paul
Loiselle is passionate about fishes. He has taken
numerous trips to Madagascar, and worked to help
conserve fishes in the wild. He has discovered and
described many new species, and breeds several that have
become extinct in the wild since he first collected them.
