River-aquifer interaction and meiofauna of hyporheic environment

The interactions that occur between surface water (rivers and lakes) and groundwater involve a number of processes that should be explored in order to understand their interconnections, since the rate of recharge and groundwater quality strongly depend on the characteristics of this interface. The area of interconnection, known as hyporheic zone is formed by a subsurface layer of sediment from the river bed and the aquifer, and its characteristics favor the establishment of some species, highlighting the meiofauna. Some biological processes responsible for modifying the recharge water quality involve those bodies. A study on hyporheic meiofauna community was performed at three points of Beberibe river, Olinda - PE. The meiofauna was composed of a total of 4965 individuals, distributed in eight taxa where 97% of organizations were represented by rotíferas, nematodes and annelids. The average total density varied between individuals 1446.3 / 10 cm2 in the summer and 12.1 individuals / 10 cm2 in winter. The community structure was correlated to the variables: winter, summer and grain size of the sediment and the combination of these factors were reflected in characteristics of hyporheic zone of Beberibe river -PE. Both in summer and in winter, the points where the densities groups were more significant were dominated by sandy fractions.