A comparison between biomonitoring methods for the analysis of macrobenthic invertebrate communities in different river types of Friuli Venezia Giulia

According to the Framework Water Directive, 2000/60/EC, macrobenthic invertebrates are very important as bioindicators for the definition of the ecological Status of lotic systems. I Italy, different collection methods are requested for the application of biotic indices in wadeable and non-wadeable rivers: a proportionally distributed multihabitat sampling (MH) and the use of artificial substrates (AS), respectively. This work was performed to compare the results obtained with both methods in three different lotic environments: an alpine stream, a high plain river and a spring fed channel. Data obtained from the application of the two different techniques have led to a good overlapping of results for all analysed watercourses, even though some macrobenthic invertebrate taxa showed selectivity in the artificial substrate colonization. No significant differences were found even among the metrics of the STAR_ICMi index, provided by the D.M. 260/2010 for the assessment of the watercourses ecological status in Italy.