Biosecurity poses the problem of how to live with and manage the complex, contingent and emergent circulations of life. This excess of circulating life manifests in a host of different circumstances: from the biopolitical attempt to sort ‘good’ from ‘bad’ circulations disrupted by a zoonotic virus making use of air transportation networks; to fluid microbial topologies that challenge the bounded individual body; from a biosurveillance network signal prompting anticipatory governance responses; to the intersection of financial and microbial geographies in the risky practices of industrial agribusiness. The ‘shock of the real’ from these eventful and everyday occurrences not only illuminates empirical connections between circulating bodies, microbes, knowledges, electronic signals, seeds, capital, food and anxiety, but also highlights that the complexity of securing processes that are elaborating new forms of life cannot be fully captured through any one theoretical lens. In this review article I consider the burgeoning field of biosecurity studies through attention to these differing concepts of circulation, and suggest neglected circulations for future research.