Publication2 med aquascape Publication1cs complete | Page 94

Derick Herrera Solano & Jennifer Contreras Picado
Costa Rica is home to 250 species of freshwater
fish (Angulo et al, 2013), representing 0.9% of the
fish species in the world. This wealth of fish fauna
is explained by the confluence of several factors
that are summarized in fish fauna division devel-
oped by Bussing (2002) where the Mesoamerican
region is divided into four provinces fish (Fig. 1),
each of them is characterized by groups species
with similar geographic distributions and ende-
mism in species and genera is also typical of each
province. In Costa Rica match three of the four
fish counties: Nicaraguan Chiapas, San Juan and
Isthmian.
However, it has not been properly recognized,
this wealth fish fauna, valued in recent years,
which has led today to a deterioration of freshwa-
ter ecosystems alarming Costa Ricans and unno-
ticed by most, worsening the situation, because
that ignorance of reality is the major cause of the
problem.
According to Bussing (2002), the worst damage to
aquatic ecosystems is difficult to perceive in a
photograph. In recent years, there has been a sig-
nificant decrease in number of species and
numbers of individuals of fish in certain rivers. In
the Central Valley, the main damage done is sew-
age, waste coffee, and industrial chemicals. In the
other sectors of the country, the use of agrochemi-
cals to irrigate crops of bananas, cocoa, cotton, rice
and pineapple periodically remove the fish fauna of
many rivers. The mills, dairies, sawmill and other
industries, also drop their waste into rivers, de-
stroying fish stocks.
Another form of pollution are sediments of land
adjacent to the rivers; erosion is a natural phenom-
enon and the fish are adapted to natural periods of
high turbidity during floods of the rainy season, but
with the clearing of forests and ploughing the land
for agriculture, the sediment carried by the rivers is
much larger and can affect some species, reducing
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