The scientific fishing for catfish in the month of May

After the activities of scientific fishing for catfish conducted in the Avigliana Lakes Natural Park in April (the report can be found here), a second campaign was also carried out in May by the staff of the National Research Council – Institute for Water Research (CNR – IRSA) with the support of the park rangers of the Protected Areas of the Cozie Alps. On this occasion, the operations were again conducted as part of the Life Predator Project, of which the Park Authority is a partner, aimed at containing Silurus glanis in the freshwater bodies of Southern Europe where it represents an invasive alien species.

Once again, operations took place in the Lago Grande di Avigliana using the electrofishing technique, which allows for the temporary stunning of fish through a weak electric discharge applied in the water, allowing for their safe recovery with a net.

Data Comparison

The May campaign was conducted over 3 days and resulted in the capture of 66 catfish for a total biomass exceeding 137 kg. In April, there were 6 days and a catch of 26 catfish per day averaging 64.4 kg. In May, the number of catfish was slightly lower (22 per day), while the average weight was considerably lower (45 kg per day). Regarding the length and weight of the individuals, the overall average for April was 65 cm with an average of 2.6 kg, while in May it was 58 cm with an average of 2.1 kg. In both sessions, individuals of both sexes were collected in almost equal measures. The largest specimens captured in the two campaigns are also comparable: the largest recovered in May reached 115 cm in length and 8.5 kg in weight, while in April it measured 120 cm and 10.7 kg.
Of great interest are also the similarities revealed by the analysis of stomach contents. As observed in the April session, in May the red swamp crayfish (Procambarus clarkii) was also confirmed as one of the main prey of the catfish in the Avigliana lakes. Crayfish remains were found in 65% of the catfish caught in April and in 74% of those caught in May.