Human behaviors that contribute to the spread of aquatic invasive species are influenced by myriad social psychological factors that vary across contexts and populations. Understanding such behavior is crucial for forming successful management strategies that minimize environmental impacts while generating support and cooperation among stakeholders. We identify several reasons why recreational anglers and boaters make decisions that benefit the environment. Specifically, our study addresses the following objectives: (1) examine reported behaviors that minimize the spread of aquatic invasive species, (2) test the effects of social normative beliefs on reported behaviors, and (3) determine the role of human-nature relationships in explaining behavioral patterns. Drawing on a path model of the decisions made by respondents who completed an on-site survey at two nature-based case study sites in Illinois, we observed that reported behavior was positively influenced by normative beliefs about those behaviors and human-nature relationships. Specifically, the Participant in Nature and Partner with Nature orientations were positively and negatively correlated with norms, respectively. In turn, norms positively predicted reported stewardship behaviors. These findings advance research on the human dimensions of aquatic invasive species by providing insights on the role of stable psychological processes that shape behavior, while informing management decisions aimed at minimizing biological invasions in freshwater ecosystems.