In southern Sinaloa, Ruiz-Luna and HernandezCornejo (1999) showed that 4 of 19 shrimp farms have replaced mangroves. Most shrimp farms in Sinaloa are located in the central and northern regions where it is possible to find shrimp ponds that interrupt the natural distribution of mangroves. This is evidence that mangroves are being displaced by shrimp farm facilities. In the state of Nayarit, and particularly in San Blas, mature mangrove ecosystems have been destroyed during construction of shrimp ponds. The implications and magnitude of the damage are still unknown.