Guimaras mangroves recovering--DENR
Mangroves heavily contaminated by last year's massive oil spill in Guimaras are showing signs of resiliency and natural recovery, according to a study of the Department of Environment and Natural Resources (DENR).
The study conducted by a team from the DENR Western Visayas office on June 18-29 showed "significant signs of recovery" including regeneration of mangroves in areas where mortality of mangroves were previously observed.
"Even in severely contaminated sites, regeneration of different species were observed to be growing robustly and in numbers," according to the report. The assessment is the third conducted in affected mangrove areas after the Solar I sank on Aug. 11, 2006 and spilled around 2.1 million liters of bunker fuel.
New leaves have grown on trees which were previously recorded as having completed defoliated. Prominent growth of lenticels were also observed in heavily contaminated plant parts, according to the report. The lenticels serve as the breathing organ of the mangroves, which when functioning normally, can enhance the recovery process.
The team also observed other signs of natural recovery including the presence of fauna such as shells and worms in the contaminated sites.
The DENR team, however, recommended further physical clean-up of oil-coated debris in three sites to enhance the natural flushing of oil from the mangroves through wave action. The sites include Sitio Dungcaan in Barangay Lucmayan; Sitio Punta Araguy in Barangay Panobolon and Sitio Tamsik in San Antonio, all in Nueva Valencia town.
The team also recommended rehabilitation measures in 21 monitored sites including planting in 152.5 hectares and the establishment of three central and six subsidiary mangrove nurseries.
A perioding monitoring (once every quarter) of the recovery should also be conducted in the 13 severely contaminated sites and assess the status of mangroves, according to the report.
The oil sludge contaminated mangroves in at least 18 barangays in the towns of Nueva Valencia (11), Sibunag (6) and San Lorenzo (1), according to a DENR assessment conducted shortlty after the oil spill.
Based on the assessment conducted two weeks after the oil spill, 13 sites were heavily contaminated and another considered slightly contaminated.
Four sites, all in Nueva Valencia, showed significant deaths of mangroves with at least 509 dead mangrove trees.
The trees that were contaminated showed signs of damage including formation of callus on the trunks and debarking of mature mangrove trees. In some trees, an oily substance was observed leaking out from the inner bark.
Rhodora Capulso, head of the DENR regional public affairs office said the death of mangroves is caused by the oil blocking the lenticels of mangroves.
She denied reports that oil dispersants caused the death of mangroves in Sitio Lucmayan in Barangay Lapaz in Nueva Valencia.
"The dispersants were used in the offshore clean-up and there is a "no-touch" policy adopted by the scientific community in the rehabilitation of mangroves," Capulso said in a telephone interview.
She said high incidence of mangrove mortality like in Lucmayan were usually concentrated in areas where the oil sludge could not be easily flushed by the sea water.