Investigation of the marine communities of Midway Harbor and adjacent lagoon, Midway Atoll, Northwest Hawaiian Islands in 1998 (NCEI Accession 0001098)

Only three invertebrates identified in this survey are considered to be nonindigenous species in the Hawaiian Islands. One introduced bryozoan, Amathia distans, dominated the fouling communities atmost stations where artificial substrates were available. Another introduced bryozoan, Schizoporella errata, was also common at the same stations.

A non indigenous barnacle, Chthamalus proteus, recently introduced from the Caribbean, was common on pier pilings inside Midway harbor. No introduced invertebrates were present in natural habitats. The introduced snapper, Lutjanus kasmira, was also present along the reef outside the lagoon.

The threat to the native reef community by established non-indigenous species is considered minimal. The presence of these introduced species at Midway, especially Chthamalus proteus, suggests that vectors of future, potentially more deleterious introductions exist. Transport of these introductions was most likely as fouling on ship bottoms, but other sources of introductions, such as ballast water carried in ships, should be guarded against to protect the relatively pristine reefs of Midway Atoll.