A NEW INTEGRATED INDEX FOR ASSESSMENT OF THE ECOLOGICAL STATUS OF RIVERS AS BASED ON FUNCTIONAL FEEDING GROUPS OF THE MACROZOOBENTHOS

摘要

Practicability of the new Integral index of the organic pollution degree (I_T) based on functional feeding groups (FFG) of the macrozoobenthos was tested for assessment of the ecological status of the Mesta river. Dynamic balance of the proportion of two functional feeding groups - shredders (SH) and deposit feeders (DF) can be indicative for the formal description of sapro-biological/ecological situation of the studied river system as far as these groups represented the marginal saprobic situations-xeno-oligosaprobity (SH) and polysaprobity (DF). The application of the newly developed Integral index I_T as based on the changes within the invertebrates' community trophic structure appeared good correlations with the degree of saprobity as a relative measure for the ecological status of the studied river system of Mesta. Using the draft national standards for presentation of ecological status by ecological quality ratio (EQR) via the Pantle and Buck's saprobic index (SPUB), the mean values and ranges for I_(TM) were calculated for each quality classes according the requirements of the European WFD 2000/60/EC.