Human-mediated dispersal is an escalating threat to freshwater biodiversity, yet the specific role of researchers themselves as vectors for aquatic invertebrates remains poorly understood. This study investigates the potential for scientists to inadvertently transport Cladocera (water fleas)—including individuals, ephippia, and remains—during sediment sampling in a shallow-water lake in the Rakamaz region of northeastern Hungary. The findings highlight the possibility that microcrustacean propagules can be redistributed during field activity, underscoring the need for careful sampling procedures and consistent sediment handling to minimise unintentional mediation and protect the integrity of freshwater ecological research.