This chapter describes semienclosed basins that receive freshwater input in relatively low volumes or with highly seasonal periodicity. In temperate basins, density gradients are dominated by salinity. In contrast, in basins with low or no freshwater discharge (described in this chapter), density gradients may also or exclusively be dominated by thermal gradients. Therefore, research on these basins, which has been scantily reported in the literature, should consider cooling and evaporation. In general, studies in these basins should include assessment of heat and water exchanges with the atmosphere, in addition to land-derived freshwater input. We know less about these systems than those in temperate latitudes because they are most likely found in tropical or subtropical latitudes or near the poles, where access to study sites is less frequent.