commercial shrimp farms is not economicallyworthwhile. This is the case even if the costsof restoring mangrove forests after shrimppond abandonment are ignored. For exam-ple,Table 3 indicates that the net presentvalue of local uses of the mangrove forestsby a small coastal community such as ThaPo Village are around $632 to $823 per ha.This is three to four times higher than theeconomic returns to shrimp farming,exclud-ing the costs of mangrove rehabilitation,thatare reported in Table 5. Once the valuesof off-shore fishery linkages and coastlineprotection are also included,it is clear thatthe economic benefits of conserving man-groves far exceed the economic returns frommangrove conversion to commercial shrimpponds.Table 5 also indicates that,if commer-cial shrimp farmers are required to restoremangrove forests,then shrimp farming inmangrove areas may not be economicallyviable. This result suggests that the de factoopen access availability of mangrove forestsfor conversion to shrimp farming in southernThailand may cause economic distortions incommercial shrimp farming in two ways.First,as shrimp farmers do not have tocompensate anyone for conversion of man-grove forests,they tend to overexploit theseresources. Shrimp farm operations are essen-tially subsidized in their use of coastal landresources; hence,the operations are finan-