The 32,000 hectare Candaba swamp in Pampanga province is now an ocean expanse after heavy monsoon rain poured over Luzon and the rest of the Philippines last week. Gone for the moment are the swathes of green rice fields that can be seen when one is traveling to the north on the section of the Candaba Viaduct of the North Luzon Expressway.
The swamp’s water obviously rose high enough to submerge every vegetation thriving in the area. Only a few mango and palm trees are out of reach of the swelling water. Small islands are formed and jut out from the vast swamp as a result of rising water.
One will have an eerie feeling when he sees the present state of the Candaba wetlands. It’s water world out there, with the full might of the swamp dangerously creeping into residential houses hugging its fringes.
The inundated Candaba Swamp is a reminder to us of what nature can restore if the environment is altered or reduced to accommodate man-made formations or structures. The Candaba Swamp is merely reclaiming its natural territory to start a rejuvenation process and play its role as an agent of biodiversity.
The Candaba Swamp is comprised of marshes, freshwater ponds and grasslands. The field is normally submerged during the wet season and dries out between November and April. Local farmers convert it into an agricultural area, where they plant rice and watermelon that are sold across the globe.
The swamp also serves as fishing grounds covering 43,000 hectares of arable farmlands. Its fields are very fertile because of the sustained deposits of humus and decaying plant residues.
For photographers and bird watchers, the Candaba Swamp is a paradise for their profession due to the many species of colorful ducks and threatened water birds that flock to the area to escape the biting cold of the northern hemisphere during the winter season. It is a staging and wintering area for ducks, egrets and other water birds, or the Anatidae species.
Migratory birds arrive from as far as Siberia, Korea, Japan, China, Australia and New Zealand to breed in the Candaba Swamp. The Department of Environment and Natural Resources says between 5,000 and 10,000 birds regularly visit the swamp from October up to April. The department has recorded 54 species of migratory birds in the wetlands since 1940. About 100,000 ducks, according to the DENR, were observed in a single day in 1982.
Aside from acting as a staging area for exotic birds, the Candaba Swamp plays a key role in preserving the ecological balance. Similar to marshes and other wetlands, the Candaba Swamp provides an important habitat for everything from microbes to frogs to waterfowl. Peatlands, mangroves, swamps and seagrass beds, according to one DENR official, are the world’s most effective carbon sinks.
Wetlands capture and store carbon from the atmosphere through plant photosynthesis and by acting as sediment traps for runoff. Carbon is held in the living vegetation as well as in litter, peats, organic soils and sediments that have built up, in some cases, over thousands of years.
Peatlands cover just 3 percent of the planet’s surface but they store about 30 percent of all land-based carbon, or twice the number of all the world’s forests combined. The same DENR official added inland wetlands, like rivers and lakes, absorb and store water from excessive rains and mitigate floods.
Swamps appear as wastelands but healthy wetlands absorb and accumulate excess rainfall that is stored for the dry season. They offset extreme weather events and protect communities from disasters. Swamps also function as kidneys of the planet because they improve water quality.
They collect surface runoff from cities and farmlands and act as natural water filter by eliminating other pollutants and catching suspended sediments that can kill aquatic plants and animals. In the case of the Candaba Swamp, it filters toxic chemicals coming from the upstream water of the Pampanga River before it drains to Manila Bay, and recharge groundwater aquifers that are crucial for irrigation and drinking water.
But the swamp’s role in the ecosystem may diminish due to challenges bedeviling the water system. A DENR executive cited excessive growth of vegetation, drying of wetlands and fishponds due to climate change, land conversion of wetland into agricultural land, and hunting, trapping and poaching of birds in the area.
Climate change, drought and land conversion may be altering the ecosystem in the swamp and turning away migratory birds, whose numbers have declined in recent years. The Candaba Swamp as a key habitat for animals and plants must be given a chance to breathe and act its role as protector of the environment.
Editor’s note: Biodiversity 101 column is open to contributors who share the advocacies of protecting the environment and promoting sustainable practices that are being pushed by the United Nations. Such contributions are subject to the availability of space and the paper’s editorial policies. The contributions should not exceed 600 words or 4,000 characters.