Scientists hit Cimatu for blaming tourism for Palawan river damage

DARKENED CAVE CEILING Candidates in the Miss Earth 2009 beauty pageant visit Puerto Princesa’s Underground River in Palawan. Environment Secretary Roy Cimatu says the caves’ ceiling has darkened, possibly caused by too many people passing through. —JOAN BONDOC

PUERTO PRINCESA CITY—A group of foreign scientists conducting studies at the Puerto Princesa Underground River (PPUR) dismissed Environment Secretary Roy Cimatu’s claim that tourism had damaged the physical features of the province’s most popular natural attraction.

The Italy-based La Venta Esplorazioni Geografiche described as “fake news” Cimatu’s statement that the regular flow of tourists had increased the cave’s carbon dioxide levels and blackened its limestone ceilings.

“We declare that during our last two expeditions, we observed carefully all the PPUR and, by our opinion, nothing is changed in the last 25 years: in particular no increase of black color has been noticed in the touristic sector of the cave,” La Venta said in a statement released by the city government’s park office.

La Venta scientists have done several expeditions inside the complex river system beneath the St. Paul limestone mountains of northern Puerto Princesa City.

They have been credited for the discovery of fossils and the documentation of previously unknown physical features of the cave, including a hidden crystal chamber.

‘Exhalation of people’

Speaking at the Philippine Environmental Summit in Cebu City on Tuesday, Cimatu said the discoloration of the underground river’s limestone ceiling was caused by carbon dioxide exhaled by visitors.

“It’s carbon. Where does the carbon come from? Exhalation of people,” he said.

Cimatu said the national government would take drastic measures to stop environmental degradation in popular tourist sites apart from Boracay Island, to include El Nido and the Underground River in Palawan, and Panglao Island in Bohol province.

President Duterte has warned he will order the  closure of Boracay due to the deterioration of its water quality.

City tourism records show that more than 250,000 tourists visited Puerto Princesa during the last quarter of last year despite a travel advisory issued by countries like the United States and the United Kingdom because of terrorism threats.

In its statement, La Venta said there had not been any reported darkening of the ceiling of the Underground River.

Properly managed

“It is clearly fake news. Carbon dioxide cannot directly turn the limestone walls and ceilings into black. It may only cause a slight increase in condensation corrosion (and consequently, the corroded rock should become white),” La Venta said.

The natural attraction, the group said, has “hundred of square meters of black crusts” that were deposited over its lifetime even before it was opened to tourists.

“Actually in remote parts of the upper galleries, black powder is actively forming in place where no more than 10 people are present in over two years,” the statement added.

La Venta also asserted that the Underground River was properly being managed by its park staff, contrary to claims that it was deteriorating because of tourism. —Redempto Anda