Historical and recent introductions of non-indigenous marine species into Pearl Harbor, Oahu, Hawaiian Islands

Abstract

The benthic organisms and fishes of Pearl Harbor were sampled in 1996, and results were compared with all previous collections and observations from Pearl Harbor assembled from published and unpublished literature and specimens in the Bishop Museum collections. Organisms were designated as native, non-indigenous or cryptogenic (i.e. of uncertain origin). Rates of introductions of non-indigenous and cryptogenic species by decade were estimated from the time of first collections in Pearl Harbor at the turn of the century. Of a total of 419 taxa collected or observed in the 1996 surveys, 95 species (23%) were introduced or cryptogenic, including 12 newly introduced species and 12 new cryptogenic species. Analysis suggests two periods of relatively high introduction rates corresponding to wartime periods. Of the 101 introduced species that have been collected from Pearl Harbor since the beginning of the century, we found 69 species (68%) in 1996. Most of the introduced species collected in 1996 with known geographic origins have distributions extending to the Indo-West Pacific; however, several species are known from the Red Sea and the Caribbean Sea. The only species from these recent introductions that has become abundant and widespread in Hawaii is the small intertidal barnacle Chthamalus proteus Dando and Southward, 1980, which was formerly restricted to the Caribbean.