Planted ‘bakhaw’ sustained worst ‘Yolanda’ damage
May I place in proper perspective the study of the Ecosystems Research and Development Bureau (ERDB) of the Department of Environment and Natural Resources (“Gov’t study shows ‘Yolanda’ damage to mangroves bigger than reported,” News, 6/2/14).
1. The reported mangrove damage applies only to plantations—which confirms our earlier findings of widespread mangrove mortality only in planted “bakhaw” (Rhizophora ) areas. In contrast, natural stands of “piapi” (Avicennia marina), “pagatpat” (Sonneratia alba) and other species are recovering. The greater damage in planted mangroves reported by the ERDB compared to our study (1,700 hectares vs 100-200 hectares) may in part be due to more sampling sites covered by the former.
2. Most bakhaw (Rhizophora stylosa, R. apiculata and R. mucronata) along the seafront are the wrong species planted in the wrong sites. The scientific community has been pointing this out for over two decades now—since the 1990s. Yet bakhaw are favored over piapi and pagatpat.
3. Dozens of scientific papers and also gray literature from NGOs and other reports provide evidence of the ecological incorrectness of these practices. Even the very low seedling counts reported by the ERDB in the bakhaw zones (83-195/ha) show their nonsuitability and poor site adaptation compared to the natural stands (475/ha) in Palo, Leyte. We found even higher average densities of 6,000-18,000 seedlings/ha in the natural mangroves in Eastern Samar.
4. Therefore we ask: Did “Yolanda” cause the devastation of the 1,700-hectare bakhaw-planted areas (per ERDB report); or were the bakhaw already dying six months, or one or two years, or more before Yolanda?
5. Even in areas still to be planted, it will do no good to plant bakhaw all over again on seagrass beds. Based on our January/March 2014 survey, the natural stands along Eastern Visayas coastlines are dominated by piapi and pagatpat, as are those in Western and Central Visayas and the archipelago. Bakhaw can be found behind the piapi-pagatpat zone and in more protected sites such as tidal creeks and rivers. The nursery protocols for A. marina and S. alba are described in the “Community-based Mangrove Rehabilitation Manual” (2012).
6. Assuming, for the sake of discussion, that the 1,700-hectare plantations were devastated by Yolanda, these represent only 6 percent of the total—the more or less 28,000-hectare mangroves-occupied shorelines at various landfall sites—from Eastern Samar to Palawan (Rollon et al., May 2014 Tacloban Workshop presentation). Meaning that 94 percent of mangroves (representing natural stands, as observed in our January/March 2014 surveys) sustained zero to only partial damage, and that our original statement remains valid—that the mangroves in the Yolanda-affected provinces are recovering and need “protection” rather than planting.
This should guide the wise use of the P1 billion and other funds earmarked for mangroves by the government, NGOs and international development agencies.
—J.H. PRIMAVERA, PhD,
Pew Fellow in Marine Conservation,
cochair, IUCN Mangrove Specialist Group,
chief mangrove scientific advisor,
Zoological Society of London,
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