Potentials and pitfalls of integrating data from diverse sources: Lessons from a historical database for Great Lakes stream fishes

There is considerable enthusiasm for, and value in, the development and ana lysis of large databases that integrate physical and biological data from d iverse sources and over broad spatial, temporal, and taxonomic scales. Ther e also are special challenges. We introduce the Biological Impacts of Low-h ead Dams (BILD) historical database, developed for assessing the impacts of small barriers used in the control of parasitic sea lamprey (Petromyzon ma rinus) on assemblages of stream fishes throughout the Great Lakes drainage basin. We also highlight challenges encountered in developing the database. Considerable effort and care were required while designing and analyzing t he database because of variability in the information the contributing agen cies had collected, as well as how the information had been collected, orga nized and stored. Furthermore, only a small portion of the data is suitable for addressing the impacts of small barriers on stream fish assemblages. W e therefore provide general recommendations for developing databases integr ating data from diverse sources and provide cautions about expectations for them. Our overview is intended to assist fisheries scientists, managers, a nd funding agencies asked either to develop an historical database, or to p rovide data or funding for one.