Illuminating the need for ecological knowledge in economic valuation of mangroves under different management regimes - a critique

This is a commentary on a paper by Gilbert and Janssen (Gilbert, A.J., Jans sen, R., 1998. Ecol. Econ. 25, 323-346) that deals with valuation of manage ment alternatives for the Pagbilao mangroves, Philippines. Our main critiqu e focuses on the undervaluation of fisheries as well as the inability to qu antify the value of ecological services and internalize aquaculture's envir onmental costs. In addition, the sustainability criteria set up for the aqu aculture management alternatives is open to debate. These weaknesses affect the result of Gilbert and Janssen's analysis so that the Value of the unex ploited mangrove forest is underestimated, and the value and sustainability of converting the forest into aquaculture ponds are overestimated. If appl ied to decision-making, the erroneous results from this partial cost-benefi t analysis may have dire consequences for the mangroves and coastal communi ties of Pagbilao. (C) 2000 Elsevier Science B.V. All rights reserved.