“…The distribution of aquatic macroinvertebrate species and communities is controlled by a variety of environmental factors such as depth, water quality (Hellawell, 1986), substrate type (Reynoldson et al, 1995;Chapman et al, 1997), sediment grain size (Tolkamp, 1980), organic matter content in sediments (Rodriguez et al, 2001;Ciutat et al, 2006) or contaminants (Clements & Kiffney, 1993;Phipps et al, 1995). The occurrence of macrophytes is also of great importance for macrozoobenthos (Hargeby et al, 1994;Scheffer, 1998;Declerck et al, 2005), as well as the presence of a "coarse" detritus (particle diameter > 480 ”m) in sediments (Moss & Timms, 1989;KornijĂłw et al, 1995;Merritt et al, 2002) which arise mainly from plant decomposition.…”