[Coral-List] biogeography entangled with ecology

[Charles Birkeland]

The present concern for terminology is mixing words from different
disciplines. “Invasive” is an ecological term, not a term focused on
distribution (biogeography). “Indigenous” (“native”) and
“nonindigenous” (exotic, alien, introduced, naturalized) are concerned
with distribution or biogeography and not species interactions.
“Invasive” has negative species interaction connotations, whether
indigenous or nonindigenous. Indigenous COTS (like locusts) are
occasionally invasive. In Hawaii, Carijoa riisei became invasive, like
many introduced species, after a long lag period of decades of
latency.  The lionfishes are nonindigenous in the western Atlantic and
became invasive remarkably rapidly. This was quite unusual. The top
shell Trochus niloticus is native to most of Melanesia and Palau and
it was widely introduced before World War II to Micronesia (Guam,
Marshalls), Kiribati, Tuvalu, Samoa, Tonga, French Polynesia and
elsewhere. Although often quite common, they have not been considered
invasive because, as far as I know, they have not been seen to have a
major effect on the native biota (and they contribute to the local
economies). The jury is still out on a grouper and a snapper that were
introduced to Hawaii over half a century ago and have become
predominant. Being common does not necessarily imply “invasive”.  Each
case needs to be assessed individually.