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CURRENT PROBLEMS
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Being
at the heart of the country’s urban and industrial center, Laguna de
Bay is threatened by inevitable price of progress-rapid population
growth, land conversion, water pollution, and over fishing. |
LAND CONVERSION
The total land area of
the Laguna de Bay watershed is approximately 2, 920
sq. km. A major transformation was noted in the region in
1996-2000. During this period, 25 percent of areas for
commercial and non-commercial forest and 67 percent for
agriculture were greatly reduced to five percent and 52
percent, respectively, as the lake region became more
industrialized.
Built-up and industrial areas now
account for 29 percent of the total land area. Open unproductive
grasslands also grew from eight to 14 percent during the same period.
These changes in land use and land cover indicate the occurrence of
deforestation which could lead to soil erosion and impair the hydrology
of the basin.

TRUE COLORS
(Landsat images (above) showing basic land cover
changes in a span of nine years)

FALSE
COLORS
(Landsat images (above) showing basic land cover
changes in a span of nine years) |
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EXOTIC SPECIES
PROLIFERATION
In
the recent years, exotic
species of plants and
aquatic organisms were
introduced into the
sub-basins that, in
turn, have reached the
lake basin. Invasive
exotic species compete
with native species for
food and space.
The Thai catfish Clarias batrachus, displaced the native catfish
Clarias macrocephalus, and the golden apple snail Pomacea
canaliculata
displaced the native snail Pila
luzonica.
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WATER POLLUTION
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Results of the
1994-2004 water quality monitoring indicated that four out of 15 (27%)
rivers draining into the lake are highly polluted in terms of biological
oxygen demand (BOD) and dissolved oxygen (DO).
These rivers include
San Pedro and San Cristobal in Laguna; Tunasan, Marikina, and Mangangate
in Metro Manila; and Sapang Baho in Rizal.
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Biochemical oxygen
demand (BOD) is a measure of the quantity of oxygen used by
microorganisms (e.g., aerobic bacteria) in the oxidation of organic
matter. Hence, high BOD level implies high presence of microorganisms
brought about by pollution.
All the 15 rivers monitored exhibit high fecal contamination exposing to
health risk about 2.7 million population.
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All
design photos/graphics remain the copyright of Laguna Lake Development Authority
Km. 24
Manila East Road, Don
Hilario Cruz Avenue, Club Manila East Compound, Brgy. San Juan
Taytay, Rizal, Philippines
Tel. Nos.
284-4796; 284-4740 loc. 3388 | E-mail us at:
llda@denr.gov.ph
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