Extinction

There are approximately 70 species of mangroves around the world (Polidoro et al. 2010). When activities such as logging, shrimp farming, coastal agriculture, hotel development, and other activities are valued over the ecosystem services the intact mangroves provide, genetic diversity is among the first—but least considered—casualty. The trees and associated species (e.g., birds, snakes, crabs) are visibly lost, but so too are the specific genotypes and phenotypes that have evolved in microhabitats around the world to withstand insects, tidal fluctuations, precipitation patterns and salinity regimes. Mangroves are not species-rich to begin with, especially in comparison with other tropical forests (Alongi 2002). And in the areas where replanting is attempted, it is often done with seeds from elsewhere, and often done with one species, rather than the mix of species that originally existed. As Polidoro et al. (2010) have stated:

“Although regeneration of degraded mangrove areas is thought to be a viable option in some areas (Saenger 2002, Walters et al. 2008), successful regeneration is generally only achieved by the planting of monocultures of fast-growing species, such as Rhizophora or Avicenna species. Many rare and slow growing species are not replaced (Alongi 2002), and many species cannot be easily replanted with success. In sum, mangrove areas may be able to be rehabilitated in some regions, but species and ecosystems cannot be effectively restored” (p. 8).

Thus, once these species and subspecies are lost, they cannot be recovered, no matter how many well-intentioned restoration efforts are made. The solution to ensuring the mangroves are there to provide the ecosystem services we depend on is not to remove them in the first place.