The turn of the 6^th and 5^th millenia BC witnessed probably the largest economic and cultural transformation of SE Europe, giving rise to a new technocomplex occupying the alluvial plains of the Tisza River and its tributaries in the southern parts of the Carpathian Basin. Representatives of the Tisza Culture were engaged in intensive farming complemented with foraging creating a complex system of hierarchical multilayered settlements (tells). The favorable natural endowments of the sites with a large variety of multiple ecotones ideal for multifocal subsistence, as well as the introduction of new farming techniques ensured the establishment of long-term sedentary lifeways. However, according to the archeology, a major shift in subsistence happened towards the end of the Late Neolithic marking the terminal part of the evolution of the culture. Traditional crop cultivation was gradually abandoned and hunting, animal husbandry gained more importance. Probably other second-line sources like fish and shellfish displayed a similar pattern. Finally, tells were disintegrated and a new cultural group emerged characterized by pastoralism. The exact background of these transformations is still unknown. In order to see whether or not potential transformations in the local alluvial environment had some role in shaping human behavior, a multiproxy paleoecological analysis was implemented on mollusk material of one of the largest tell sites of SE Hungary. Freshwater mollusks collected by humans in themselves characterize the quality of the water body from which they derive. They are also an excellent marker of socioeconomic response to environmental stress. According to our findings the emergence of new settlement phases and the intensified foraging could have been correlated with alteration in stream properties.