1810-39 1840-69 1870-99 1900-29 1930-59 1960-92 Figure 21.1. Time-course of the establishment (i.e., first detection in the wild) of alien species in the fresh waters of the Hudson River basin. Modified from Mills etal. (1996, 1997).
Table 21.2. Major vectors that have brought alien aquatic species into the Hudson basin, modified