The National Sea Grant College Program, in conjunction with the Great Lakes Sea Grant Network, has recently launched the Sea Grant Nonindigenous Species Site (SGNIS). Intended to serve as a national information center, SGNIS is structured as a database and provides "a comprehensive collection of research publications and education materials ... on zebra mussels and other aquatic nuisance species." The database is searchable by Title, Authors, Organization, Date of publication, or Keywords (subject), and typical returns provide hyperlinks to abstracts, and in come cases, the full text (.pdf format) of published articles. In addition to the publications listed here, a selection of external links points users to additional sites. This is an excellent resource, well conceived and up to date.