Agriculture and Environment: Shrimp
Environmental Impacts of Production: Nonnative Species
For some time, the species Penaeus vannamei from the west coast of Latin America has been farmed along the Caribbean and Atlantic coasts from South Carolina to Brazil and more recently in Asia.
Likewise, shrimp of the species P. monodon from Asia have been transported throughout Asia and brought to Latin America. P. monodon shrimp from Africa have been taken to Asia and the Pacific, and there has been a flow of this same species from Southeast Asia to South Asia and vice versa. Escapes, however, have not yet shown up in wild shrimp catch.
The introduction of shrimp from different regions, even of the same species, introduces new DNA and the characteristics that have not evolved in situ.
These interactions are probably insignificant within ponds, but when shrimp escape during winter exchange or harvest they could cause genetic pollution that could alter the inbred characteristics, and perhaps the viability, of wild populations.
Spread of diseases
The introduction of disease pathogens from other areas is equally important. Diseases previously found only in Taiwan and China have now spread throughout Asia and even into Latin America, where they have caused billions of dollars in damage each year. The impact of disease pathogens on wild stocks is not documented, but anecdotal information suggests that it may be serious.
Drastic reduction in shrimp populations
For example, in 1992-93 when diseases reduced shrimp aquaculture production in China by 60-70%, the production of wild-caught shrimp in that country also declined by 90%. It is not clear whether the disease was transmitted from the wild to the ponds or vice versa, but there does seem to be some direct relationship.