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Exotic Aquatic Organisms - International Development Research ...

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Appendix I<br />

Definitions of <strong>Exotic</strong>s<br />

The 1986 ASFA Thesaurus gives a "scope note" or "rough definition" of introduced species<br />

as "Establishment in a new geographical area of a species by migration or artificial<br />

transportation."<br />

The same Thesaurus gives a "rough definition" of transplantation as "Artificial" introduction<br />

of organisms into habitats where they do not occur naturally.<br />

The ASFA Thesaurus does not use the word exotic.<br />

Welcomme, R.L. 1988. (<strong>International</strong> introductions of inland aquatic species. FAO Tech.<br />

Pap. 294, 318 p.) follows the 1987 EIFAC Code of Practice, which used these definitions.<br />

Introduced species (includes both non-indigenous and exotic species): Any species<br />

intentionally or accidentally transported and released by man into an environment outside<br />

its present range.<br />

Transferred species (includes transplanted species): Any species intentionally or<br />

accidentally transported and released within its present range.<br />

"Transfers are usually intended to support stressed populations, introduce genetic<br />

diversity into a stock or to reestablish a species whose stocks have failed locally.<br />

Introductions are intended to insert a totally new element into the fauna".<br />

Welcomme commented, "One reservation is made with respect to these definitions in that a<br />

species is considered to have been introduced to a country once it has crossed national<br />

boundaries. This means that species are included in the listing if they are transported into a<br />

country as part of current commercial practice for food or ornament and not for stocking into<br />

natural environments. Experience has shown that even such species may have impacts through<br />

the release of pathogens or through escape."<br />

Marine species: Any aquatic species that does not spend its entire life cycle in fresh<br />

water.<br />

Introduced species (= non-indigenous species; includes both non-indigenous and exotic<br />

species): Any species intentionally or accidentally transported and released by man into<br />

an environment outside its present range.<br />

Transferred species (= transplanted species): Any species intentionally or accidentally<br />

transported and released within its present range.<br />

Quarantined species: Any species held in a confined or enclosed system that is designed<br />

to prevent any possibility of the release of the species, or any of its diseases or any other<br />

associated organisms into the environment.<br />

139

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