It has been demonstrated that Macro Benthos need cold and well-oxygenated waters for their survival, they are very susceptible to contamination caused by man. Any human activity can increase water temperature and eliminate nymphs from their habitat. For this reason, an elevated number of macrobenthos is considered to be an excellent indicator of water quality for streams and rivers. The laying of the steel pipeline of 1km long requires the use of chemical compounds in order to destroy the rocks. It is evident that some of these chemical will flow in the stream causing irreversible damages to the natural balance.
The European bullhead is a useful indicator of water quality, he does not tolerate even slightly polluted waters. It is a nocturnal fish, resting during the day on the riverbed hiding among stones and algae. Its particular body composition makes it easily recognizable: only 15 cm length, a broad head, wide pectoral fins looking like wings and a rounded tail. It mainly feeds on macro bentonic population.
Rainbow trout live in cold and highly-oxygenated waters. Their survival depends on larvae, fish eggs, and insects in. the macro benthic population. Any reduction in the macro benthic population will compromise the population of rainbow trout. Trouts are a primary interest of fishermen. A decline in numbers will discourage the sport fishing in Sorba Valley and a eco-sustainable form of consumption.