The recent invasion of water lilies in a portion of the Pasig River may have been due to water pollution from fertilizers used in aquaculture farming and domestic wastes, according to an office of the Department of Environment and Natural Resources (DENR).
DENR's Pasig River Coordinating and Management Office (PRCMO) said water lilies or water hyacinths are usually observed thriving in Pasig River during the rainy season.
"The recent proliferation of the aquatic plant in the Pasig River can be attributed to the high level of nutrients in the water, probably because of aquaculture farming areas in the upstream portion of the Pasig River System, as well as due to the domestic wastes that drain from the tributaries to the main river," PRCMO said in a social media post.
The DENR office called on the public to be "environmentally-responsible" to prevent from further polluting the Pasig River.
During a cleanup in Parola, Tondo last weekend, the department's "river warriors" were able to collect around 120 sacks of waste along the riverbanks near the entrance to Manila Bay.
Most of the wastes that were recovered were domestic or household wastes from residents living near or along waterways and water hyacinths flowing from Laguna de Bay, the PRCMO said.
It said that with the collective efforts of DENR-PRCMO and its partner-stakeholders, "we will not only stop the spread of water hyacinths, but more importantly, stop the abuse and misuse of our waterways for a cleaner, healthier, and safer environment and a better future."
Water hyacinth, with scientific name "Eichhoria crassipes," is an aquatic plant which can live and reproduce while floating on the surface of freshwaters.
The plant size ranges from six inches to 38 inches depending on its growing condition.
Its rate of proliferation under certain growth habitat could be extremely rapid, causing vast infestation of large areas of water.