Wetlands
Covering
about 4,600 hectares, wetlands around Manila Bay are useful in:
·
providing
food and habitat for fish, shorebirds and wildlife;
·
maintaining
and improving water quality of rivers, lakes and estuaries,
·
acting
as reservoir for watersheds, and
·
protecting
adjacent and downstream properties of the area from potential flood damage
Mudflats,
sand flats, swamps, beaches and rocky shores form part of the wetlands in
Manila Bay. Found mostly along the coast of Bataan and Pampanga, mudflats are
suitable habitats for shellfish.
Coral
Reefs
Contributing
to the balanced functioning of the ecosystem around Manila Bay, coral reefs in
the area provide sanctuary for fishes. Consequently, its decline through the
years has directly affected the fish yield.
Seagrass Beds
As a
diverse ecosystem, seagrass beds provide shelter for fishes and other marine
life forms. Like the coral reefs, most of the seagrass beds in Manila Bay are
found near its mouth, most notably in the areas of Malolos,Orion, Marivels,
Bataan and Corregidor.
Upland forests
Within
the watershed of Manila Bay upland forests abound which are sources of food,
timber, fuel wood and other products, as well as habitats for wildlife. These
forests provide protection from soil erosion and help maintain the water levels
and water quality in rivers and streams. Mount Makiling, Angat Dam watershed,
La Mesa Dam watershed, Mount Palay-Palay,
Fig.1 Area Map
Fig. 2
CONCLUDE AND APPLY:
1. Are all wetlands the same?
There
different types of wetlands:
·
Marsh
– a type of wetland ecosystem characterized by poorly drained mineral soils and
by plant life dominated by grasses. Marshes are common at the mouths of rivers,
especially where extensive deltas have been built. The marsh plants slow down
the flow of water and allow for the nutrient enriched sediments to be
deposited, thus providing conditions for the further development of the marsh.
·
Swamp
– a wetland ecosystem characterized by mineral soils with poor drainage and by
plant life dominated by trees. Swamps are found throughout the world, most
often in low-lying regions (with poor drainage) next to rivers, which supply
the swamp with water. Some swamps develop from marshes that slowly fill in,
allowing trees and woody shrubs to grow.
·
Bog – a type of wetland ecosystem characterized by wet, spongy, poorly
drained peaty soil, dominated by the growth of bog mosses, Sphagnum, and heaths, particularly Chamaedaphne. Bogs are usually acid areas, frequently
surrounding a body of open water. Bogs receive water exclusively from rainfall.
·
Fen – a type of wetland ecosystem characterized by peaty soil,
dominated by grasslike plants, grasses, sedges, and reeds. Fens are alkaline
rather than acid areas, receiving water mostly from surface and groundwater
sources.
2. What is the ecological
significance of the wetland area that you studied for that region of the
country?
Wetlands prevent flooding by holding
water much like a sponge. By doing so, wetlands help keep river levels normal
and filter and purify the surface water.
Wetlands accept water during storms
and whenever water levels are high. When water levels are low, wetlands slowly
release water.
Many animals that live in other
habitats use wetlands for migration or reproduction. For example, herons nest
in large old trees, but need shallow areas in order to wade for fish and
aquatic life. Amphibians often forage in upland areas but return to the water
to mate and reproduce.
While wetlands are truly unique,
they must not be thought of as isolated and independent habitat. To the
contrary, wetlands are vital to the health of all other biomes and to wildlife
and humans everywhere.
Unlike most other habitats, wetlands
directly improve other ecosystems. Because of its many cleansing benefits,
wetlands have been compared to kidneys. The analogy is good one. Wetlands and
kidneys both help control water flow and cleanse the system.
3. Why should wetland
environments be protected?
Because wetlands
also clean the water by filtering out sedimentation, decomposing vegetative
matter and converting chemicals into useable form. The ability of wetlands to
recycle nutrients makes them critical in the overall functioning of earth. No
other ecosystem is as productive, nor as unique in this conversion process. In
some places artificial wetlands were developed solely for the purpose of water
purification.
Sources:
http://www.personal.ceu.hu/students/03/nature_conservation/wwddetail/Types_classif.html
http://www.unepscs.org/Wetlands_Training/Wetland%20Case%20Studies%20and%20Country%20Reports/37-Management-Coastal-Wetlands-Manila-Bay-Philippines.pdf
Wikipedia
