Abstract
Non-indigenous species have long been employed by aquaculturists. In some instances these species had been introduced and become accepted members of the local ecosystem long before they were reared by aquaculturists. Tilapia in Asia are a good example. In other cases, problems associated with the culture of local species led culturists to find related non-indigenous species as alternatives. Examples are the introduction of Latin American shrimp species into the United States and Atlantic salmon, (Salmo salar), to the west coast of North America. The use of non-indigenous species is more widely accepted in association with inland aquaculture than marine aquaculture. A number of diseases, primarily viral in nature, have occurred on shrimp farms around the world. Countries that have used non-indigenous shrimp species have not been immune to the problem, so diseases have been imported along with the shrimp. There is a major concern that these diseases will spread to native populations. The lack of assurance that animals cultured in the marine environment can be contained is a major factor. Escape as a result of culture system failure, vandalism, accidents and carelessness cannot be completely avoided. Concerns that escapees will become established and possibly displace native species have prompted the marine aquaculture community to reconsider the use of non-indigenous species in general and to concentrate on local species.