Labile zones are readily open to change. They are unstable structures continually undergoing chemical, physical, or biological transformations. The relation between land and sea in a labile zone involves several contemporary categories that can be deconstructed through the analysis of endogenous intersections. Using ethnography as a method and the microsystems of fisheries as case studies, this lecture delves into the concept of vernacular to decipher human/other-than-human entanglements. Ethno-design emerges as a relevant framework for observing, collating, and analysing processes linking humans and non-humans, particularly humans and fish. The alliances established between humans, fish, and molluscs produce information and data whose representations extend across time, space, and cosmologies. Grasping these data and entanglements sheds light on the ongoing processes occurring in the unstable areas between land and sea.