With the global glacier retreat at the onset of the Holocene, unconstrained drainage systems gradually became colonized by a myriad of species – aquatic plants, fish, molluscs and water fowl, as well as humans who made their lives along flowing water. The clustering of a number of Mesolithic sites – e.g. along the Muge and Sado valleys in Portugal, in the Danube Gorges of the North-Central Balkans, and in the Dnieper Rapids region in Ukraine – reveals a close connection with riverine environments, through seasonal visits, more permanent settlement, or in the events of the burial of the dead. Numerous archaeozoological, stable isotope and lipid residue analyses indicate that aquatic food sources constituted an important part of the diet, insofar that the term 'fishers' rather than 'hunter-gatherers' is perhaps more accurate when describing many early-mid Holocene communities in Europe. While Mesolithic research has been firmly embedded in the study of the environment, it was primarily conceptualized as a resource to be exploited or a passive backdrop to human activity. In more recent times, the paradigm shift known as the Ontological Turn afforded new ways of thinking about actors and material worlds whose properties do not simply exist, but emerge through mutually constitutive relationships. With their constant flow and ever-changing form, shifting between the seasons of freezing and flooding, pulsing with life during migratory fish runs, shaped by human agency and shaping human experience of the world, the rivers quite literally embody the vibrant nature of entanglement. Far from being one-sided, or two-sided even, these interactions were interwoven with the dynamics of the ecosystem as a whole, eliciting various multispecies responses. In this paper, rivers flowing through Mesolithic worlds are considered as socialized landscapes, mediums which afforded specific experiences and interspecies encounters, and as dynamic assemblages of beings and abiotic actors.

The author acknowledges financial support of the Ministry of Education, Science and Technological Development of the Republic of Serbia (Grant No. 451-03-9/2021-14/200358)