ILOILO City – A government policy allowing the transfer of mangroves for infrastructure projects is facing sharp scientific opposition, with a leading mangrove expert warning that the rule could undermine the country’s natural coastal defenses and climate resilience.
In a Feb. 23, 2026 letter to Environment Secretary Raphael Lotilla, Dr. Jurgenne H. Primavera, chief mangrove scientific adviser of the Zoological Society of London and member of the National Academy of Science and Technology, urged the Department of Environment and Natural Resources (DENR) to rescind its Oct. 8, 2025 memorandum that sets interim guidelines for the earthballing and transfer of mangroves under what it calls “exceptional circumstances.”
While the directive reiterates that mangroves should not be removed or disturbed, it provides exemptions in cases involving public safety risks or infrastructure flagship projects endorsed by the government’s economic planning body. It requires proponents to follow “established methodologies” and comply with issuances of the Ecosystems Research and Development Bureau, Forest Management Bureau, and Biodiversity Management Bureau.
Primavera pointed out that the memorandum does not include or clearly detail these methodologies, raising concerns about how relocations would be scientifically undertaken and monitored.
She cited scientific studies showing that transferring mature mangroves results in poor survival rates. In 2019, DENR Region 6 stopped earthballing activities along the Iloilo River after observing the low survival of transplanted mangroves.
Primavera also referred to findings of the Mangrove Specialist Group of the International Union for Conservation of Nature (IUCN), which noted limited research support for mangrove transplantation due to physiological stress and logistical challenges in handling large trees in muddy coastal zones.
During a DENR roundtable discussion on sustainable coastal development in March 2025, experts presented data reflecting low survival outcomes for earthballed mangroves. A study from China reported only 20 to 25 percent survival after 10 months. A DENR–Ecosystems Research and Development Bureau study showed an average survival rate of 10 percent, while Australian research documented mortality within 2.5 years for mangroves with trunk diameters exceeding 5 centimeters.
Data from Ibajay, Aklan show that mature mangroves typically measure 9 to 16 centimeters in trunk diameter, indicating that many relocated trees may not survive.
Primavera stressed that mangroves are critical to climate resilience, acting as natural barriers against storm surges, coastal erosion, and flooding.
She cited the Jaro, Iloilo Floodway Project, where infrastructure development later saw the growth of a 40-hectare mangrove greenbelt, as an example of how nature-based approaches can complement development.
The Global Mangrove Alliance Philippines earlier called on the DENR and the Department of Public Works and Highways to review approvals involving mangrove earthballing tied to infrastructure projects.
Primavera renewed her appeal for the DENR to withdraw the October 2025 memorandum and ensure that coastal development policies are grounded in scientific evidence and long-term environmental sustainability./PN
