Rivers, streams, and reservoirs are vitally important natural resources within landscapes that are threatened by anthropogenic activities such as land-use change, non-native species introduction, and over-fishing. These inland waters frequently form borders between nations, and require international collaborations to effectively monitor, manage and conserve native biodiversity and the ecosystems services they provide. Mesoamerica, a region that extends from southern Mexico to Panama, includes numerous freshwater bodies that define international boundaries. This region is characterized by high biodiversity and impoverished human populations that rely on the integrity of freshwaters; however, the ecology of Mesoamerican watersheds is relatively understudied. Our research in Mesoamerica will continue to address the effects of armored catfish on freshwater communities and ecosystems and will continue asking basic research questions focused on understanding linkages among species identity, ecological stoichiometry, consumer-driven nutrient dynamics, and ecosystem processes. Our research will also address: 1) the effects of dam construction ecosystem services provided by freshwaters, 2) the effects of urbanization and agricultural conversion (pastures to bananas to African palms) on community structure and ecosystem function of lotic systems, and 3) the impacts of tourism and land use change on freshwater systems within protected areas.