BALLAST WATER AS A VECTOR FOR TINTINNID TRANSPORT

Ballast tanks of cargo ships arriving in Coos Bay, Oregon, USA, from v arious Japanese ports were sampled from October 1987 to January 1991. A total of 33 tintinnid species from 15 genera were identified from ba llast water samples. Live tintinnids were observed on occasion. Many o f the species that were observed in these ballast water samples have a lso been found in the nearby Strait of Juan de Fuca, but others have n ever been reported in the eastern Pacific. The presence of tintinnids in ballast water obfuscates any conclusions about the natural distribu tions of these species. This study suggests that ballast water has bee n a vector for tintinnid transport, for many years, and that it may no longer be possible to determine the native distributions for many tin tinnid species.